Extend ldap3's start_tls and fix tests

Author: jorgectf

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

@@ -219,6 +219,11 @@ private module LDAP {
               .(DataFlow::LocalSourceNode)
               .flowsTo([serverCall.getArg(2), serverCall.getArgByName("use_ssl")])
         )
+        or
+        exists(DataFlow::AttrRead startTLS |
+          startTLS.getAttributeName().matches("%start_tls%") and
+          startTLS.getObject().getALocalSource() = this
+        )
       }
     }
 

python/ql/test/experimental/query-tests/Security/CWE-522/ldap3_remote.py

@@ -48,7 +48,7 @@ def three():
 def four():
     host = "ldap://" + remote_host
 
-    srv = Server(host, port=1337, True)
+    srv = Server(host, 1337, True)
     conn = Connection(srv, "dn", "password")
     conn.search("dn", "search_filter")
     return conn.response
@@ -87,7 +87,7 @@ def six():
 def seven():
     host = schema + request.args['host']
 
-    srv = Server(host, port=1337, True)
+    srv = Server(host, 1337, True)
     conn = Connection(srv, "dn", "password")
     conn.search("dn", "search_filter")
     return conn.response
@@ -112,7 +112,7 @@ def eight():
 @app.route("/nine")
 def nine():
     host = schema + "somethingon.theinternet.com"
-    srv = Server(host, port=1337, False)
+    srv = Server(host, 1337, False)
     conn = Connection(srv, "dn", "password")
     conn.search("dn", "search_filter")
     return conn.response