Ruby: add SqlConstruction concept

Author: nickrolfe

ruby/ql/lib/codeql/ruby/Concepts.qll

@@ -11,9 +11,47 @@ private import codeql.ruby.Frameworks
 private import codeql.ruby.dataflow.RemoteFlowSources
 private import codeql.ruby.ApiGraphs
 
+/**
+ * A data-flow node that constructs a SQL statement.
+ *
+ * Often, it is worthy of an alert if a SQL statement is constructed such that
+ * executing it would be a security risk.
+ *
+ * If it is important that the SQL statement is indeed executed, use `SqlExecution`.
+ *
+ * Extend this class to refine existing API models. If you want to model new APIs,
+ * extend `SqlConstruction::Range` instead.
+ */
+class SqlConstruction extends DataFlow::Node instanceof SqlConstruction::Range {
+  /** Gets the argument that specifies the SQL statements to be constructed. */
+  DataFlow::Node getSql() { result = super.getSql() }
+}
+
+/** Provides a class for modeling new SQL execution APIs. */
+module SqlConstruction {
+  /**
+   * A data-flow node that constructs a SQL statement.
+   *
+   * Often, it is worthy of an alert if a SQL statement is constructed such that
+   * executing it would be a security risk.
+   *
+   * If it is important that the SQL statement is indeed executed, use `SqlExecution`.
+   *
+   * Extend this class to model new APIs. If you want to refine existing API models,
+   * extend `SqlConstruction` instead.
+   */
+  abstract class Range extends DataFlow::Node {
+    /** Gets the argument that specifies the SQL statements to be constructed. */
+    abstract DataFlow::Node getSql();
+  }
+}
+
 /**
  * A data-flow node that executes SQL statements.
  *
+ * If the context of interest is such that merely constructing a SQL statement
+ * would be valuable to report, consider using `SqlConstruction`.
+ *
  * Extend this class to refine existing API models. If you want to model new APIs,
  * extend `SqlExecution::Range` instead.
  */
@@ -27,6 +65,9 @@ module SqlExecution {
   /**
    * A data-flow node that executes SQL statements.
    *
+   * If the context of interest is such that merely constructing a SQL
+   * statement would be valuable to report, consider using `SqlConstruction`.
+   *
    * Extend this class to model new APIs. If you want to refine existing API models,
    * extend `SqlExecution` instead.
    */

ruby/ql/lib/codeql/ruby/security/SqlInjectionCustomizations.qll

@@ -25,12 +25,19 @@ module SqlInjection {
   private class RemoteFlowSourceAsSource extends Source, RemoteFlowSource { }
 
   /**
-   * A SQL statement of a SQL execution, considered as a flow sink.
+   * An SQL statement of a SQL execution, considered as a flow sink.
    */
   private class SqlExecutionAsSink extends Sink {
     SqlExecutionAsSink() { this = any(SqlExecution e).getSql() }
   }
 
+  /**
+   * An SQL statement of a SQL construction, considered as a flow sink.
+   */
+  private class SqlConstructionAsSink extends Sink {
+    SqlConstructionAsSink() { this = any(SqlConstruction e).getSql() }
+  }
+
   /**
    * A comparison with a constant string, considered as a sanitizer-guard.
    */