C#: Re-factor RegexInjection to use the new API.

Author: michaelnebel

csharp/ql/lib/semmle/code/csharp/security/dataflow/RegexInjectionQuery.qll

@@ -24,9 +24,11 @@ abstract class Sink extends DataFlow::ExprNode { }
 abstract class Sanitizer extends DataFlow::ExprNode { }
 
 /**
+ * DEPRECATED: Use `RegexInjection` instead.
+ *
  * A taint-tracking configuration for untrusted user input used to construct regular expressions.
  */
-class TaintTrackingConfiguration extends TaintTracking::Configuration {
+deprecated class TaintTrackingConfiguration extends TaintTracking::Configuration {
   TaintTrackingConfiguration() { this = "RegexInjection" }
 
   override predicate isSource(DataFlow::Node source) { source instanceof Source }
@@ -36,6 +38,22 @@ class TaintTrackingConfiguration extends TaintTracking::Configuration {
   override predicate isSanitizer(DataFlow::Node node) { node instanceof Sanitizer }
 }
 
+/**
+ * A taint-tracking configuration for untrusted user input used to construct regular expressions.
+ */
+private module RegexInjectionConfig implements DataFlow::ConfigSig {
+  predicate isSource(DataFlow::Node source) { source instanceof Source }
+
+  predicate isSink(DataFlow::Node sink) { sink instanceof Sink }
+
+  predicate isBarrier(DataFlow::Node node) { node instanceof Sanitizer }
+}
+
+/**
+ * A taint-tracking module for untrusted user input used to construct regular expressions.
+ */
+module RegexInjection = TaintTracking::Global<RegexInjectionConfig>;
+
 /** A source of remote user input. */
 class RemoteSource extends Source instanceof RemoteFlowSource { }
 

csharp/ql/src/Security Features/CWE-730/RegexInjection.ql

@@ -16,11 +16,11 @@
 import csharp
 import semmle.code.csharp.security.dataflow.RegexInjectionQuery
 import semmle.code.csharp.frameworks.system.text.RegularExpressions
-import semmle.code.csharp.dataflow.DataFlow::DataFlow::PathGraph
+import RegexInjection::PathGraph
 
-from TaintTrackingConfiguration c, DataFlow::PathNode source, DataFlow::PathNode sink
+from RegexInjection::PathNode source, RegexInjection::PathNode sink
 where
-  c.hasFlowPath(source, sink) and
+  RegexInjection::flowPath(source, sink) and
   // No global timeout set
   not exists(RegexGlobalTimeout r)
 select sink.getNode(), source, sink, "This regular expression is constructed from a $@.",