Java: Refactor XSS.ql

Author: aschackmull

java/ql/src/Security/CWE/CWE-079/XSS.ql

@@ -14,25 +14,26 @@
 import java
 import semmle.code.java.dataflow.FlowSources
 import semmle.code.java.security.XSS
-import DataFlow::PathGraph
 
-class XssConfig extends TaintTracking::Configuration {
-  XssConfig() { this = "XSSConfig" }
+module XssConfig implements DataFlow::ConfigSig {
+  predicate isSource(DataFlow::Node source) { source instanceof RemoteFlowSource }
 
-  override predicate isSource(DataFlow::Node source) { source instanceof RemoteFlowSource }
+  predicate isSink(DataFlow::Node sink) { sink instanceof XssSink }
 
-  override predicate isSink(DataFlow::Node sink) { sink instanceof XssSink }
+  predicate isBarrier(DataFlow::Node node) { node instanceof XssSanitizer }
 
-  override predicate isSanitizer(DataFlow::Node node) { node instanceof XssSanitizer }
+  predicate isBarrierOut(DataFlow::Node node) { node instanceof XssSinkBarrier }
 
-  override predicate isSanitizerOut(DataFlow::Node node) { node instanceof XssSinkBarrier }
-
-  override predicate isAdditionalTaintStep(DataFlow::Node node1, DataFlow::Node node2) {
+  predicate isAdditionalFlowStep(DataFlow::Node node1, DataFlow::Node node2) {
     any(XssAdditionalTaintStep s).step(node1, node2)
   }
 }
 
-from DataFlow::PathNode source, DataFlow::PathNode sink, XssConfig conf
-where conf.hasFlowPath(source, sink)
+module XssFlow = TaintTracking::Make<XssConfig>;
+
+import XssFlow::PathGraph
+
+from XssFlow::PathNode source, XssFlow::PathNode sink
+where XssFlow::hasFlowPath(source, sink)
 select sink.getNode(), source, sink, "Cross-site scripting vulnerability due to a $@.",
   source.getNode(), "user-provided value"