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

Author: michaelnebel

csharp/ql/src/Security Features/InsecureRandomness.ql

@@ -14,7 +14,7 @@
 
 import csharp
 import semmle.code.csharp.frameworks.Test
-import semmle.code.csharp.dataflow.DataFlow::DataFlow::PathGraph
+import Random::InsecureRandomness::PathGraph
 
 module Random {
   import semmle.code.csharp.security.dataflow.flowsources.Remote
@@ -38,21 +38,24 @@ module Random {
   /**
    * A taint-tracking configuration for insecure randomness in security sensitive context.
    */
-  class TaintTrackingConfiguration extends TaintTracking::Configuration {
-    TaintTrackingConfiguration() { this = "RandomDataFlowConfiguration" }
+  module InsecureRandomnessConfig implements DataFlow::ConfigSig {
+    predicate isSource(DataFlow::Node source) { source instanceof Source }
 
-    override predicate isSource(DataFlow::Node source) { source instanceof Source }
+    predicate isSink(DataFlow::Node sink) { sink instanceof Sink }
 
-    override predicate isSink(DataFlow::Node sink) { sink instanceof Sink }
+    predicate isBarrier(DataFlow::Node node) { node instanceof Sanitizer }
 
-    override predicate isSanitizer(DataFlow::Node node) { node instanceof Sanitizer }
-
-    override predicate isAdditionalTaintStep(DataFlow::Node pred, DataFlow::Node succ) {
+    predicate isAdditionalFlowStep(DataFlow::Node pred, DataFlow::Node succ) {
       // succ = array_or_indexer[pred] - use of random numbers in an index
       succ.asExpr().(ElementAccess).getAnIndex() = pred.asExpr()
     }
   }
 
+  /**
+   * A taint-tracking module for insecure randomness in security sensitive context.
+   */
+  module InsecureRandomness = TaintTracking::Global<InsecureRandomnessConfig>;
+
   /** A source of cryptographically insecure random numbers. */
   class RandomSource extends Source {
     RandomSource() {
@@ -112,10 +115,8 @@ module Random {
   }
 }
 
-from
-  Random::TaintTrackingConfiguration randomTracking, DataFlow::PathNode source,
-  DataFlow::PathNode sink
-where randomTracking.hasFlowPath(source, sink)
+from Random::InsecureRandomness::PathNode source, Random::InsecureRandomness::PathNode sink
+where Random::InsecureRandomness::flowPath(source, sink)
 select sink.getNode(), source, sink,
   "This uses a cryptographically insecure random number generated at $@ in a security context.",
   source.getNode(), source.getNode().toString()