Add SqlAlchemy module

Author: mrthankyou

python/ql/src/experimental/semmle/python/frameworks/SqlAlchemy.qll

@@ -0,0 +1,70 @@
+/**
+ * Provides classes modeling security-relevant aspects of the 'SqlAlchemy' package.
+ * See https://pypi.org/project/SQLAlchemy/.
+ */
+
+private import python
+private import semmle.python.dataflow.new.DataFlow
+private import semmle.python.dataflow.new.TaintTracking
+private import semmle.python.ApiGraphs
+
+
+private module SqlAlchemy {
+  private class SqlAlchemySessionInstance extends API::Node {
+    SqlAlchemySessionInstance() {
+      this in [
+          API::moduleImport("sqlalchemy.orm").getMember("Session").getReturn(),
+          API::moduleImport("sqlalchemy.orm").getMember("sessionmaker").getReturn().getReturn()
+        ]
+    }
+
+    override string toString() { result = "Use of SqlAlchemy Session instance method" }
+  }
+
+  private class SqlAlchemyEngineInstance extends API::Node {
+    SqlAlchemyEngineInstance() {
+      this = API::moduleImport("sqlalchemy").getMember("create_engine").getReturn()
+    }
+
+    override string toString() { result = "Use of SqlAlchemy Engine instance method" }
+  }
+
+  private class SqlAlchemyQueryInstance extends API::Node {
+    SqlAlchemyQueryInstance() {
+      this instanceof SqlAlchemySessionInstance and
+      this = this.getMember("query").getReturn()
+    }
+
+    override string toString() { result = "Use of SqlAlchemy Query instance method" }
+  }
+
+  private class SqlAlchemyExecuteCall extends DataFlow::CallCfgNode, SqlExecution::Range {
+    SqlAlchemyExecuteCall() {
+      exists(SqlAlchemySessionInstance sessionInstance, SqlAlchemyEngineInstance engineInstance |
+        this = sessionInstance.getMember("execute").getACall() or
+        this = engineInstance.getMember("connect").getReturn().getMember("execute").getACall() or
+        this = engineInstance.getMember("begin").getReturn().getMember("execute").getACall()
+      )
+    }
+
+    override DataFlow::Node getSql() { result = this.getArg(0) }
+  }
+
+  private class SqlAlchemyScalarCall extends DataFlow::CallCfgNode, SqlExecution::Range {
+    SqlAlchemyScalarCall() {
+      exists(SqlAlchemySessionInstance sessionInstance |
+        this = sessionInstance.getMember("scalar").getACall()
+      )
+    }
+
+    override DataFlow::Node getSql() { result = this.getArg(0) }
+  }
+
+  private class SqlAlchemyQueryCall extends DataFlow::CallCfgNode, SqlExecution::Range {
+    SqlAlchemyQueryCall() {
+      exists(SqlAlchemyQueryInstance queryInstance | this = queryInstance.getAMember().getACall())
+    }
+
+    override DataFlow::Node getSql() { result = this.getArg(0) }
+  }
+}