Swift: Add consistent CSV extension points.

Author: geoffw0

swift/ql/lib/codeql/swift/security/CleartextLoggingExtensions.qll

@@ -25,6 +25,9 @@ class CleartextLoggingAdditionalTaintStep extends Unit {
   abstract predicate step(DataFlow::Node n1, DataFlow::Node n2);
 }
 
+/**
+ * A sink defined in a CSV model.
+ */
 private class DefaultCleartextLoggingSink extends CleartextLoggingSink {
   DefaultCleartextLoggingSink() { sinkNode(this, "logging") }
 }

swift/ql/lib/codeql/swift/security/PathInjectionExtensions.qll

@@ -29,6 +29,9 @@ class PathInjectionAdditionalTaintStep extends Unit {
   abstract predicate step(DataFlow::Node node1, DataFlow::Node node2);
 }
 
+/**
+ * A sink defined in a CSV model.
+ */
 private class DefaultPathInjectionSink extends PathInjectionSink {
   DefaultPathInjectionSink() { sinkNode(this, "path-injection") }
 }

swift/ql/lib/codeql/swift/security/PredicateInjectionExtensions.qll

@@ -24,6 +24,9 @@ class PredicateInjectionAdditionalTaintStep extends Unit {
   abstract predicate step(DataFlow::Node n1, DataFlow::Node n2);
 }
 
+/**
+ * A sink defined in a CSV model.
+ */
 private class DefaultPredicateInjectionSink extends PredicateInjectionSink {
   DefaultPredicateInjectionSink() { sinkNode(this, "predicate-injection") }
 }

swift/ql/lib/codeql/swift/security/UncontrolledFormatStringExtensions.qll

@@ -34,7 +34,7 @@ private class DefaultUncontrolledFormatStringSink extends UncontrolledFormatStri
     // the format argument to a `FormattingFunctionCall`.
     this.asExpr() = any(FormattingFunctionCall fc).getFormat()
     or
-    // a sink defined in a Csv model.
+    // a sink defined in a CSV model.
     sinkNode(this, "uncontrolled-format-string")
   }
 }

swift/ql/lib/codeql/swift/security/XXEExtensions.qll

@@ -4,6 +4,7 @@ import swift
 private import codeql.swift.dataflow.DataFlow
 private import codeql.swift.frameworks.AEXML
 private import codeql.swift.frameworks.Libxml2
+private import codeql.swift.dataflow.ExternalFlow
 
 /** A data flow sink for XML external entities (XXE) vulnerabilities. */
 abstract class XxeSink extends DataFlow::Node { }
@@ -201,3 +202,10 @@ private predicate lib2xmlOptionLocalTaintStep(DataFlow::Node source, DataFlow::N
     source.asExpr() = int32Init.getAnArgument().getExpr() and sink.asExpr() = int32Init
   )
 }
+
+/**
+ * A sink defined in a CSV model.
+ */
+private class DefaultXxeSink extends XxeSink {
+  DefaultXxeSink() { sinkNode(this, "xxe") }
+}