More cleanups for bug #56814 and some more external entity leaks of #…

…56164 git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1617849 13f79535-47bb-0310-9956-ffa450edef68
apache · Aug 13, 2014 · eabb6a9 · eabb6a9
1 parent cd80405
commit eabb6a9
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Showing 10 changed files with 109 additions and 81 deletions.
diff --git a/src/ooxml/java/org/apache/poi/openxml4j/opc/PackageRelationshipCollection.java b/src/ooxml/java/org/apache/poi/openxml4j/opc/PackageRelationshipCollection.java
@@ -24,9 +24,9 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 
 import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
 import org.apache.poi.openxml4j.exceptions.InvalidOperationException;
+import org.apache.poi.util.DocumentHelper;
 import org.apache.poi.util.POILogFactory;
 import org.apache.poi.util.POILogger;
-import org.apache.poi.util.SAXHelper;
 import org.w3c.dom.Attr;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
@@ -311,7 +311,7 @@ private void parseRelationshipsPart(PackagePart relPart)
             throws InvalidFormatException {
         try {
             logger.log(POILogger.DEBUG, "Parsing relationship: " + relPart.getPartName());
-            Document xmlRelationshipsDoc = SAXHelper.readSAXDocument(relPart.getInputStream());
+            Document xmlRelationshipsDoc = DocumentHelper.readDocument(relPart.getInputStream());
 
             // Browse default types
             Element root = xmlRelationshipsDoc.getDocumentElement();

diff --git a/src/ooxml/java/org/apache/poi/openxml4j/opc/internal/ContentTypeManager.java b/src/ooxml/java/org/apache/poi/openxml4j/opc/internal/ContentTypeManager.java
@@ -33,7 +33,6 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 import org.apache.poi.openxml4j.opc.PackagePartName;
 import org.apache.poi.openxml4j.opc.PackagingURIHelper;
 import org.apache.poi.util.DocumentHelper;
-import org.apache.poi.util.SAXHelper;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.NodeList;
@@ -371,7 +370,7 @@ public void clearOverrideContentTypes() {
 	private void parseContentTypesFile(InputStream in)
 			throws InvalidFormatException {
 		try {
-			Document xmlContentTypetDoc = SAXHelper.readSAXDocument(in);
+			Document xmlContentTypetDoc = DocumentHelper.readDocument(in);
 
 			// Default content types
 			NodeList defaultTypes = xmlContentTypetDoc.getDocumentElement().getElementsByTagName(DEFAULT_TAG_NAME);

diff --git a/...va/org/apache/poi/openxml4j/opc/internal/unmarshallers/PackagePropertiesUnmarshaller.java b/...va/org/apache/poi/openxml4j/opc/internal/unmarshallers/PackagePropertiesUnmarshaller.java
@@ -31,7 +31,7 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 import org.apache.poi.openxml4j.opc.internal.PackagePropertiesPart;
 import org.apache.poi.openxml4j.opc.internal.PartUnmarshaller;
 import org.apache.poi.openxml4j.opc.internal.ZipHelper;
-import org.apache.poi.util.SAXHelper;
+import org.apache.poi.util.DocumentHelper;
 import org.w3c.dom.Attr;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
@@ -105,7 +105,7 @@ public PackagePart unmarshall(UnmarshallContext context, InputStream in)
 
 		Document xmlDoc;
 		try {
-			xmlDoc = SAXHelper.readSAXDocument(in);
+			xmlDoc = DocumentHelper.readDocument(in);
 
 			/* Check OPC compliance */
 

diff --git a/src/ooxml/java/org/apache/poi/util/DocumentHelper.java b/src/ooxml/java/org/apache/poi/util/DocumentHelper.java
@@ -17,6 +17,10 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 
 package org.apache.poi.util;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.reflect.Method;
+
 import javax.xml.XMLConstants;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
@@ -25,20 +29,78 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
+import org.xml.sax.SAXException;
 
-public class DocumentHelper {
+public final class DocumentHelper {
+    private static POILogger logger = POILogFactory.getLogger(DocumentHelper.class);
+
+    private DocumentHelper() {}
 
-    private static final DocumentBuilder newDocumentBuilder;
-    static {
+    /**
+     * Creates a new document builder, with sensible defaults
+     */
+    public static synchronized DocumentBuilder newDocumentBuilder() {
         try {
-            newDocumentBuilder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
+            DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
+            documentBuilder.setEntityResolver(SAXHelper.IGNORING_ENTITY_RESOLVER);
+            return documentBuilder;
         } catch (ParserConfigurationException e) {
             throw new IllegalStateException("cannot create a DocumentBuilder", e);
         }
     }
 
+    private static final DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
+    static {
+        documentBuilderFactory.setNamespaceAware(true);
+        documentBuilderFactory.setValidating(false);
+        trySetSAXFeature(documentBuilderFactory, XMLConstants.FEATURE_SECURE_PROCESSING, true);
+        trySetXercesSecurityManager(documentBuilderFactory);
+    }
+
+    private static void trySetSAXFeature(DocumentBuilderFactory documentBuilderFactory, String feature, boolean enabled) {
+        try {
+            documentBuilderFactory.setFeature(feature, enabled);
+        } catch (Exception e) {
+            logger.log(POILogger.INFO, "SAX Feature unsupported", feature, e);
+        }
+    }
+    private static void trySetXercesSecurityManager(DocumentBuilderFactory documentBuilderFactory) {
+        // Try built-in JVM one first, standalone if not
+        for (String securityManagerClassName : new String[] {
+                "com.sun.org.apache.xerces.internal.util.SecurityManager",
+                "org.apache.xerces.util.SecurityManager"
+        }) {
+            try {
+                Object mgr = Class.forName(securityManagerClassName).newInstance();
+                Method setLimit = mgr.getClass().getMethod("setEntityExpansionLimit", Integer.TYPE);
+                setLimit.invoke(mgr, 4096);
+                documentBuilderFactory.setAttribute("http://apache.org/xml/properties/security-manager", mgr);
+                // Stop once one can be setup without error
+                return;
+            } catch (Exception e) {
+                logger.log(POILogger.INFO, "SAX Security Manager could not be setup", e);
+            }
+        }
+    }
+
+    /**
+     * Parses the given stream via the default (sensible)
+     * DocumentBuilder
+     * @param inp Stream to read the XML data from
+     * @return the parsed Document 
+     */
+    public static Document readDocument(InputStream inp) throws IOException, SAXException {
+        return newDocumentBuilder().parse(inp);
+    }
+
+    // must only be used to create empty documents, do not use it for parsing!
+    private static final DocumentBuilder documentBuilderSingleton = newDocumentBuilder();
+
+    /**
+     * Creates a new DOM Document
+     */
     public static synchronized Document createDocument() {
-        return newDocumentBuilder.newDocument();
+        return documentBuilderSingleton.newDocument();
     }
 
     /**

diff --git a/src/ooxml/java/org/apache/poi/util/SAXHelper.java b/src/ooxml/java/org/apache/poi/util/SAXHelper.java
@@ -18,19 +18,17 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 package org.apache.poi.util;
 
 import java.io.IOException;
-import java.io.InputStream;
 import java.io.StringReader;
 import java.lang.reflect.Method;
 
 import javax.xml.XMLConstants;
-import javax.xml.parsers.DocumentBuilder;
-import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.parsers.SAXParserFactory;
 
-import org.w3c.dom.Document;
 import org.xml.sax.EntityResolver;
 import org.xml.sax.InputSource;
 import org.xml.sax.SAXException;
+import org.xml.sax.XMLReader;
 
 
 /**
@@ -39,43 +37,43 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 public final class SAXHelper {
     private static POILogger logger = POILogFactory.getLogger(SAXHelper.class);
 
-    private static final EntityResolver IGNORING_ENTITY_RESOLVER = new EntityResolver() {
+    private SAXHelper() {}
+
+    /**
+     * Creates a new SAX XMLReader, with sensible defaults
+     */
+    public static synchronized XMLReader newXMLReader() throws SAXException, ParserConfigurationException {
+        XMLReader xmlReader = saxFactory.newSAXParser().getXMLReader();
+        xmlReader.setEntityResolver(IGNORING_ENTITY_RESOLVER);
+        trySetSAXFeature(xmlReader, XMLConstants.FEATURE_SECURE_PROCESSING, true);
+        trySetXercesSecurityManager(xmlReader);
+        return xmlReader;
+    }
+
+    static final EntityResolver IGNORING_ENTITY_RESOLVER = new EntityResolver() {
         @Override
         public InputSource resolveEntity(String publicId, String systemId)
                 throws SAXException, IOException {
             return new InputSource(new StringReader(""));
         }
     };
-
-    private static final DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
+    
+    private static final SAXParserFactory saxFactory;
     static {
-        documentBuilderFactory.setNamespaceAware(true);
-        documentBuilderFactory.setValidating(false);
-        trySetSAXFeature(documentBuilderFactory, XMLConstants.FEATURE_SECURE_PROCESSING, true);
-        trySetXercesSecurityManager(documentBuilderFactory);
-    }
-
-    /**
-     * Creates a new document builder, with sensible defaults
-     */
-    public static synchronized DocumentBuilder getDocumentBuilder() {
-        try {
-            DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
-            documentBuilder.setEntityResolver(IGNORING_ENTITY_RESOLVER);
-            return documentBuilder;
-        } catch (ParserConfigurationException e) {
-            throw new IllegalStateException("cannot create a DocumentBuilder", e);
-        }
+        saxFactory = SAXParserFactory.newInstance();
+        saxFactory.setValidating(false);
+        saxFactory.setNamespaceAware(true);
     }
-
-    private static void trySetSAXFeature(DocumentBuilderFactory documentBuilderFactory, String feature, boolean enabled) {
+            
+    private static void trySetSAXFeature(XMLReader xmlReader, String feature, boolean enabled) {
         try {
-            documentBuilderFactory.setFeature(feature, enabled);
+            xmlReader.setFeature(feature, enabled);
         } catch (Exception e) {
             logger.log(POILogger.INFO, "SAX Feature unsupported", feature, e);
         }
     }
-    private static void trySetXercesSecurityManager(DocumentBuilderFactory documentBuilderFactory) {
+
+    private static void trySetXercesSecurityManager(XMLReader xmlReader) {
         // Try built-in JVM one first, standalone if not
         for (String securityManagerClassName : new String[] {
                 "com.sun.org.apache.xerces.internal.util.SecurityManager",
@@ -85,22 +83,12 @@ private static void trySetXercesSecurityManager(DocumentBuilderFactory documentB
                 Object mgr = Class.forName(securityManagerClassName).newInstance();
                 Method setLimit = mgr.getClass().getMethod("setEntityExpansionLimit", Integer.TYPE);
                 setLimit.invoke(mgr, 4096);
-                documentBuilderFactory.setAttribute("http://apache.org/xml/properties/security-manager", mgr);
+                xmlReader.setProperty("http://apache.org/xml/properties/security-manager", mgr);
                 // Stop once one can be setup without error
                 return;
             } catch (Exception e) {
                 logger.log(POILogger.INFO, "SAX Security Manager could not be setup", e);
             }
         }
     }
-
-    /**
-     * Parses the given stream via the default (sensible)
-     * SAX Reader
-     * @param inp Stream to read the XML data from
-     * @return the SAX processed Document 
-     */
-    public static Document readSAXDocument(InputStream inp) throws IOException, SAXException {
-        return getDocumentBuilder().parse(inp);
-    }
 }
diff --git a/src/ooxml/java/org/apache/poi/xssf/eventusermodel/ReadOnlySharedStringsTable.java b/src/ooxml/java/org/apache/poi/xssf/eventusermodel/ReadOnlySharedStringsTable.java
@@ -22,12 +22,11 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 import java.util.List;
 
 import javax.xml.parsers.ParserConfigurationException;
-import javax.xml.parsers.SAXParser;
-import javax.xml.parsers.SAXParserFactory;
 
 import org.apache.poi.openxml4j.opc.OPCPackage;
 import org.apache.poi.openxml4j.opc.PackagePart;
 import org.apache.poi.openxml4j.opc.PackageRelationship;
+import org.apache.poi.util.SAXHelper;
 import org.apache.poi.xssf.usermodel.XSSFRelation;
 import org.xml.sax.Attributes;
 import org.xml.sax.InputSource;
@@ -134,10 +133,8 @@ public ReadOnlySharedStringsTable(PackagePart part, PackageRelationship rel_igno
      */
     public void readFrom(InputStream is) throws IOException, SAXException {
         InputSource sheetSource = new InputSource(is);
-        SAXParserFactory saxFactory = SAXParserFactory.newInstance();
         try {
-           SAXParser saxParser = saxFactory.newSAXParser();
-           XMLReader sheetParser = saxParser.getXMLReader();
+           XMLReader sheetParser = SAXHelper.newXMLReader();
            sheetParser.setContentHandler(this);
            sheetParser.parse(sheetSource);
         } catch(ParserConfigurationException e) {

diff --git a/src/ooxml/java/org/apache/poi/xssf/extractor/XSSFEventBasedExcelExtractor.java b/src/ooxml/java/org/apache/poi/xssf/extractor/XSSFEventBasedExcelExtractor.java
@@ -24,8 +24,6 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 import java.util.Map;
 
 import javax.xml.parsers.ParserConfigurationException;
-import javax.xml.parsers.SAXParser;
-import javax.xml.parsers.SAXParserFactory;
 
 import org.apache.poi.POIXMLProperties;
 import org.apache.poi.POIXMLProperties.CoreProperties;
@@ -35,6 +33,7 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 import org.apache.poi.openxml4j.exceptions.OpenXML4JException;
 import org.apache.poi.openxml4j.opc.OPCPackage;
 import org.apache.poi.ss.usermodel.DataFormatter;
+import org.apache.poi.util.SAXHelper;
 import org.apache.poi.xssf.eventusermodel.ReadOnlySharedStringsTable;
 import org.apache.poi.xssf.eventusermodel.XSSFReader;
 import org.apache.poi.xssf.eventusermodel.XSSFSheetXMLHandler;
@@ -174,10 +173,8 @@ public void processSheet(
        }
 
        InputSource sheetSource = new InputSource(sheetInputStream);
-       SAXParserFactory saxFactory = SAXParserFactory.newInstance();
        try {
-          SAXParser saxParser = saxFactory.newSAXParser();
-          XMLReader sheetParser = saxParser.getXMLReader();
+          XMLReader sheetParser = SAXHelper.newXMLReader();
           ContentHandler handler = new XSSFSheetXMLHandler(
                 styles, comments, strings, sheetContentsExtractor, formatter, formulasNotResults);
           sheetParser.setContentHandler(handler);

diff --git a/src/ooxml/java/org/apache/poi/xssf/extractor/XSSFExportToXml.java b/src/ooxml/java/org/apache/poi/xssf/extractor/XSSFExportToXml.java
@@ -28,8 +28,6 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 import java.util.Map;
 import java.util.Vector;
 
-import javax.xml.parsers.DocumentBuilder;
-import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.transform.OutputKeys;
 import javax.xml.transform.Source;
@@ -45,7 +43,7 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
 import org.apache.poi.ss.usermodel.Cell;
 import org.apache.poi.ss.usermodel.DateUtil;
-import org.apache.poi.util.XMLHelper;
+import org.apache.poi.util.DocumentHelper;
 import org.apache.poi.xssf.usermodel.XSSFCell;
 import org.apache.poi.xssf.usermodel.XSSFMap;
 import org.apache.poi.xssf.usermodel.XSSFRow;
@@ -106,15 +104,6 @@ public void exportToXML(OutputStream os, boolean validate) throws SAXException,
         exportToXML(os, "UTF-8", validate);
     }
 
-    private Document getEmptyDocument() throws ParserConfigurationException{
-
-        DocumentBuilderFactory dbfac = XMLHelper.getDocumentBuilderFactory();
-        DocumentBuilder docBuilder = dbfac.newDocumentBuilder();
-        Document doc = docBuilder.newDocument();
-
-        return doc;
-    }
-
     /**
      * Exports the data in an XML stream
      *
@@ -132,7 +121,7 @@ public void exportToXML(OutputStream os, String encoding, boolean validate) thro
 
         String rootElement = map.getCtMap().getRootElement();
 
-        Document doc = getEmptyDocument();
+        Document doc = DocumentHelper.createDocument();
 
         Element root = null;
 

diff --git a/src/ooxml/java/org/apache/poi/xssf/extractor/XSSFImportFromXML.java b/src/ooxml/java/org/apache/poi/xssf/extractor/XSSFImportFromXML.java
@@ -24,16 +24,15 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 
 import javax.xml.namespace.NamespaceContext;
 import javax.xml.parsers.DocumentBuilder;
-import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.xpath.XPath;
 import javax.xml.xpath.XPathConstants;
 import javax.xml.xpath.XPathExpressionException;
 import javax.xml.xpath.XPathFactory;
 
+import org.apache.poi.util.DocumentHelper;
 import org.apache.poi.util.POILogFactory;
 import org.apache.poi.util.POILogger;
-import org.apache.poi.util.XMLHelper;
 import org.apache.poi.xssf.usermodel.XSSFCell;
 import org.apache.poi.xssf.usermodel.XSSFMap;
 import org.apache.poi.xssf.usermodel.XSSFRow;
@@ -76,11 +75,9 @@ public XSSFImportFromXML(XSSFMap map) {
      * @throws ParserConfigurationException if there are problems with XML parser configuration
      * @throws IOException  if there are problems reading the input string
      */
-    public void importFromXML(String xmlInputString) throws SAXException, XPathExpressionException, ParserConfigurationException, IOException {
+    public void importFromXML(String xmlInputString) throws SAXException, XPathExpressionException, IOException {
 
-        DocumentBuilderFactory factory = XMLHelper.getDocumentBuilderFactory();
-        factory.setNamespaceAware(true);
-        DocumentBuilder builder = factory.newDocumentBuilder();
+        DocumentBuilder builder = DocumentHelper.newDocumentBuilder();
 
         Document doc = builder.parse(new InputSource(new StringReader(xmlInputString.trim())));