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WIP: backport XXE vulnerability fix #55

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WIP: backport XXE vulnerability fix #55

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20 changes: 18 additions & 2 deletions src/net/sf/freecol/common/io/FreeColXMLReader.java
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Original file line number Diff line number Diff line change
Expand Up @@ -88,7 +88,7 @@ public FreeColXMLReader(InputStream inputStream) throws IOException {
super();

try {
XMLInputFactory xif = XMLInputFactory.newInstance();
XMLInputFactory xif = newXMLInputFactory();
setParent(xif.createXMLStreamReader(inputStream, "UTF-8"));
} catch (XMLStreamException e) {
throw new IOException(e);
Expand All @@ -109,7 +109,7 @@ public FreeColXMLReader(Reader reader) throws IOException {
super();

try {
XMLInputFactory xif = XMLInputFactory.newInstance();
XMLInputFactory xif = newXMLInputFactory();
setParent(xif.createXMLStreamReader(reader));
} catch (XMLStreamException e) {
throw new IOException(e);
Expand All @@ -118,6 +118,22 @@ public FreeColXMLReader(Reader reader) throws IOException {
this.readScope = ReadScope.NORMAL;
}

/**
* Create a new XMLInputFactory.
*
* Respond to CVE 2018-1000825.
*
* @return A new <code>XMLInputFactory</code>.
*/
private static XMLInputFactory newXMLInputFactory() {
XMLInputFactory xif = XMLInputFactory.newInstance();
// This disables DTDs entirely for that factory
xif.setProperty(XMLInputFactory.SUPPORT_DTD, false);
// disable external entities
xif.setProperty("javax.xml.stream.isSupportingExternalEntities", false);
return xif;
}


/**
* Should reads from this stream intern their objects into the
Expand Down
3 changes: 3 additions & 0 deletions src/net/sf/freecol/common/io/FreeColXMLWriter.java
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Expand Up @@ -42,6 +42,7 @@
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import javax.xml.XMLConstants;

import net.sf.freecol.common.model.FreeColObject;
import net.sf.freecol.common.model.Location;
Expand Down Expand Up @@ -237,6 +238,8 @@ public void close() {
.toString()));
result = new StreamResult(this.outputWriter);
factory = TransformerFactory.newInstance();
factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, "");
factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_STYLESHEET, "");
transformer = factory.newTransformer();
for (int i = 0; i < indentProps.length; i += 2) {
transformer.setOutputProperty(indentProps[i],
Expand Down
3 changes: 3 additions & 0 deletions src/net/sf/freecol/common/model/FreeColObject.java
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Expand Up @@ -49,6 +49,7 @@
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.XMLConstants;

import net.sf.freecol.common.ObjectWithId;
import net.sf.freecol.common.io.FreeColXMLReader;
Expand Down Expand Up @@ -895,6 +896,8 @@ public static String readId(Element element) {
public void readFromXMLElement(Element element) {
try {
TransformerFactory factory = TransformerFactory.newInstance();
factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, "");
factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_STYLESHEET, "");
Transformer xmlTransformer = factory.newTransformer();
StringWriter stringWriter = new StringWriter();
xmlTransformer.transform(new DOMSource(element),
Expand Down
3 changes: 3 additions & 0 deletions src/net/sf/freecol/common/networking/Connection.java
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Original file line number Diff line number Diff line change
Expand Up @@ -40,6 +40,7 @@
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.XMLConstants;

import net.sf.freecol.common.FreeColException;
import net.sf.freecol.common.debug.FreeColDebugger;
Expand Down Expand Up @@ -101,6 +102,8 @@ protected Connection(String name) {
Transformer myTransformer = null;
try {
TransformerFactory factory = TransformerFactory.newInstance();
factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, "");
factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_STYLESHEET, "");
myTransformer = factory.newTransformer();
myTransformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION,
"yes");
Expand Down
3 changes: 3 additions & 0 deletions src/net/sf/freecol/common/networking/DOMMessage.java
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Expand Up @@ -37,6 +37,7 @@
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.XMLConstants;

import net.sf.freecol.common.io.FreeColXMLWriter;
import net.sf.freecol.common.debug.FreeColDebugger;
Expand Down Expand Up @@ -448,6 +449,8 @@ public static Element getChildElement(Element element, String tagName) {
public static String elementToString(Element element) {
try {
TransformerFactory factory = TransformerFactory.newInstance();
factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, "");
factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_STYLESHEET, "");
Transformer xt = factory.newTransformer();
StringWriter sw = new StringWriter();
xt.transform(new DOMSource(element), new StreamResult(sw));
Expand Down
3 changes: 3 additions & 0 deletions src/net/sf/freecol/tools/GenerateDocumentation.java
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Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,7 @@
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.XMLConstants;

import net.sf.freecol.common.i18n.Messages;
import net.sf.freecol.common.model.StringTemplate;
Expand Down Expand Up @@ -192,6 +193,8 @@ public static void generateDocumentation(String[] languages) {
Messages.loadMessageBundle(Messages.getLocale(languageCode));
try {
TransformerFactory factory = TransformerFactory.newInstance();
factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, "");
factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_STYLESHEET, "");
Source xsl = new StreamSource(new File("doc", XSL));
Transformer stylesheet;
try {
Expand Down