ppkarwasz commented on code in PR #201: URL: https://github.com/apache/roller/pull/201#discussion_r4181781498
########## app/src/main/java/org/apache/roller/weblogger/util/SecureXmlParsers.java: ########## @@ -0,0 +1,94 @@ +/* + * 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. For additional information regarding + * copyright in this work, please see the NOTICE file in the top level + * directory of this distribution. + */ + +package org.apache.roller.weblogger.util; + +import javax.xml.parsers.ParserConfigurationException; +import javax.xml.parsers.SAXParserFactory; + +import org.apache.commons.xml.secure.SecureSAXParserFactory; +import org.apache.xmlrpc.util.SAXParsers; +import org.jdom2.JDOMException; +import org.jdom2.input.sax.XMLReaderJDOMFactory; +import org.xml.sax.SAXException; +import org.xml.sax.XMLReader; + +/** + * The XML parser configuration Roller uses for every document it parses itself. + * + * <p>Parsers come from Apache Commons Secure XML, which configures the JAXP + * implementation so that nothing a document names is resolved, and throws + * rather than continuing if a setting cannot be applied. On top of that, + * Roller refuses any document type declaration: none of the documents Roller + * reads needs one. + */ +public final class SecureXmlParsers { + + /** Xerces feature name, honoured by the JDK's own parser. */ + static final String DISALLOW_DOCTYPE = + "http://apache.org/xml/features/disallow-doctype-decl";; + + /** Supplies JDOM with readers from {@link #newSAXParserFactory()}. */ + public static final XMLReaderJDOMFactory JDOM_READERS = new XMLReaderJDOMFactory() { + @Override + public XMLReader createXMLReader() throws JDOMException { + try { + return newSAXParserFactory().newSAXParser().getXMLReader(); Review Comment: The new `1.1.0` version of Commons Secure XML, which is already under vote and will be released today, introduces `SecureSAXParserFactory.newNSXMLReader()`. ########## app/src/main/java/org/apache/roller/weblogger/util/SecureXmlParsers.java: ########## @@ -0,0 +1,94 @@ +/* + * 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. For additional information regarding + * copyright in this work, please see the NOTICE file in the top level + * directory of this distribution. + */ + +package org.apache.roller.weblogger.util; + +import javax.xml.parsers.ParserConfigurationException; +import javax.xml.parsers.SAXParserFactory; + +import org.apache.commons.xml.secure.SecureSAXParserFactory; +import org.apache.xmlrpc.util.SAXParsers; +import org.jdom2.JDOMException; +import org.jdom2.input.sax.XMLReaderJDOMFactory; +import org.xml.sax.SAXException; +import org.xml.sax.XMLReader; + +/** + * The XML parser configuration Roller uses for every document it parses itself. + * + * <p>Parsers come from Apache Commons Secure XML, which configures the JAXP + * implementation so that nothing a document names is resolved, and throws + * rather than continuing if a setting cannot be applied. On top of that, + * Roller refuses any document type declaration: none of the documents Roller + * reads needs one. + */ +public final class SecureXmlParsers { + + /** Xerces feature name, honoured by the JDK's own parser. */ + static final String DISALLOW_DOCTYPE = + "http://apache.org/xml/features/disallow-doctype-decl";; + + /** Supplies JDOM with readers from {@link #newSAXParserFactory()}. */ + public static final XMLReaderJDOMFactory JDOM_READERS = new XMLReaderJDOMFactory() { + @Override + public XMLReader createXMLReader() throws JDOMException { + try { + return newSAXParserFactory().newSAXParser().getXMLReader(); + } catch (ParserConfigurationException | SAXException e) { + throw new JDOMException("Could not create an XML reader", e); + } + } + + @Override + public boolean isValidating() { + return false; + } + }; + + private SecureXmlParsers() { + } + + /** + * Returns a namespace-aware, non-validating SAX parser factory that + * resolves nothing a document names and refuses document type + * declarations. + * + * @throws IllegalStateException if the configuration cannot be applied + */ + public static SAXParserFactory newSAXParserFactory() { + SAXParserFactory factory = SecureSAXParserFactory.newNSInstance(); + factory.setValidating(false); + try { + factory.setFeature(DISALLOW_DOCTYPE, true); + } catch (ParserConfigurationException | SAXException e) { + throw new IllegalStateException( + "The XML parser does not support refusing document type declarations", e); + } Review Comment: If https://github.com/apache/roller/pull/198#discussion_r4181617672 is implemented, I don't think there is a compelling reason to disable `DOCTYPE`. As far as I know, only SOAP and XMPP explicitly ban `DOCTYPE` declarations. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
