Python: Allow import of refined variable

However, as illustrated by the `CWE-327-InsecureProtocol` test, this fix
is NOT good enough, since now even the `secure_context` is considered to
be insecure (for both versions). Ouch.

Will fix this in a later commit, since it was only discoverd late on.

Author: RasmusWL

python/ql/lib/change-notes/2023-02-17-import-refined-variable.md

@@ -0,0 +1,4 @@
+---
+category: minorAnalysis
+---
+* Fixed module resolution so we allow imports of definitions that have had an attribute assigned to it, such as `class Foo; Foo.bar = 42`.

python/ql/lib/semmle/python/dataflow/new/internal/ImportResolution.qll

@@ -79,6 +79,9 @@ module ImportResolution {
         or
         // to handle definitions guarded by if-then-else
         essaDef = v.getDefinition().(PhiFunction).getAnInput()
+        or
+        // refined variable
+        essaDef = v.getDefinition().(EssaNodeRefinement).getInput().getDefinition()
       )
     |
       defn.getNode() = essaDef.(AssignmentDefinition).getValue()

python/ql/test/experimental/import-resolution/main.py

@@ -95,7 +95,7 @@ def local_import():
 
 # check that refined definitions are handled correctly
 import refined # $ imports=refined as=refined
-check("refined.SOURCE", refined.SOURCE, refined.SOURCE, globals()) #$ MISSING: prints=SOURCE
+check("refined.SOURCE", refined.SOURCE, refined.SOURCE, globals()) #$ prints=SOURCE
 
 exit(__file__)
 

python/ql/test/query-tests/Security/CWE-327-InsecureProtocol/InsecureProtocol.expected

@@ -13,8 +13,12 @@
 | import_all_one_file.py:25:14:25:45 | ControlFlowNode for copy_completely_insecure_context | Insecure SSL/TLS protocol version TLSv1 allowed by $@. | import_all_one_file.py:9:36:9:67 | ControlFlowNode for Attribute() | call to ssl.SSLContext |
 | import_all_one_file.py:25:14:25:45 | ControlFlowNode for copy_completely_insecure_context | Insecure SSL/TLS protocol version TLSv1_1 allowed by $@. | import_all_one_file.py:9:36:9:67 | ControlFlowNode for Attribute() | call to ssl.SSLContext |
 | import_all_one_file.py:29:14:29:39 | ControlFlowNode for copy_also_insecure_context | Insecure SSL/TLS protocol version TLSv1_1 allowed by $@. | import_all_one_file.py:12:30:12:61 | ControlFlowNode for Attribute() | call to ssl.SSLContext |
+| import_use.py:9:14:9:27 | ControlFlowNode for secure_context | Insecure SSL/TLS protocol version TLSv1 allowed by $@. | import_def.py:3:18:3:49 | ControlFlowNode for Attribute() | call to ssl.SSLContext |
+| import_use.py:9:14:9:27 | ControlFlowNode for secure_context | Insecure SSL/TLS protocol version TLSv1_1 allowed by $@. | import_def.py:3:18:3:49 | ControlFlowNode for Attribute() | call to ssl.SSLContext |
 | import_use.py:13:14:13:40 | ControlFlowNode for completely_insecure_context | Insecure SSL/TLS protocol version TLSv1 allowed by $@. | import_def.py:7:31:7:62 | ControlFlowNode for Attribute() | call to ssl.SSLContext |
 | import_use.py:13:14:13:40 | ControlFlowNode for completely_insecure_context | Insecure SSL/TLS protocol version TLSv1_1 allowed by $@. | import_def.py:7:31:7:62 | ControlFlowNode for Attribute() | call to ssl.SSLContext |
+| import_use.py:17:14:17:34 | ControlFlowNode for also_insecure_context | Insecure SSL/TLS protocol version TLSv1 allowed by $@. | import_def.py:10:25:10:56 | ControlFlowNode for Attribute() | call to ssl.SSLContext |
+| import_use.py:17:14:17:34 | ControlFlowNode for also_insecure_context | Insecure SSL/TLS protocol version TLSv1_1 allowed by $@. | import_def.py:10:25:10:56 | ControlFlowNode for Attribute() | call to ssl.SSLContext |
 | pyOpenSSL_fluent.py:8:27:8:33 | ControlFlowNode for context | Insecure SSL/TLS protocol version SSLv2 allowed by $@. | pyOpenSSL_fluent.py:6:15:6:44 | ControlFlowNode for Attribute() | call to SSL.Context |
 | pyOpenSSL_fluent.py:8:27:8:33 | ControlFlowNode for context | Insecure SSL/TLS protocol version SSLv3 allowed by $@. | pyOpenSSL_fluent.py:6:15:6:44 | ControlFlowNode for Attribute() | call to SSL.Context |
 | pyOpenSSL_fluent.py:8:27:8:33 | ControlFlowNode for context | Insecure SSL/TLS protocol version TLSv1 allowed by $@. | pyOpenSSL_fluent.py:6:15:6:44 | ControlFlowNode for Attribute() | call to SSL.Context |