Fix Impacket logoff session id check (#291)

Fixes the session lookup logic when the logoff response contains a
session id of 0. This occurs when using an Impacket server and will have
the client just lookup the session id from the request.

Also adjusts the connection cache clearing behaviour to remove the
connection from the cache regardless of the result of the disconnect
behaviour.

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 1.14.1 - TBD
+
+* Add workaround for Impackets logoff response not setting the session id for message verification
+* Remove connection from global connection cache even if failing to close it
+
 ## 1.14.0 - 2024-08-26
 
 * Dropped support for Python 3.7

pyproject.toml

@@ -6,7 +6,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "smbprotocol"
-version = "1.14.0"
+version = "1.14.1"
 description = "Interact with a server using the SMB 2/3 Protocol"
 readme = "README.md"
 requires-python = ">=3.8"

src/smbclient/_pool.py

@@ -440,10 +440,10 @@ def reset_connection_cache(fail_on_error=True, connection_cache=None):
     if connection_cache is None:
         connection_cache = _SMB_CONNECTIONS
 
-    for name, connection in list(connection_cache.items()):
+    for name in list(connection_cache.keys()):
+        connection = connection_cache.pop(name)
         try:
             connection.disconnect()
-            del connection_cache[name]
         except Exception as e:
             if fail_on_error:
                 raise

src/smbprotocol/connection.py

@@ -1360,8 +1360,12 @@ def _process_message_thread(self):
                     # unreliable for async responses. Instead get the Session Id from the original request object if
                     # the Session Id is 0xFFFFFFFFFFFFFFFF.
                     # https://social.msdn.microsoft.com/Forums/en-US/a580f7bc-6746-4876-83db-6ac209b202c4/mssmb2-change-notify-response-sessionid?forum=os_fileservices
+                    # Impacket also sets session id to 0 on the logoff response
+                    # so fallback to the request for that one
+                    # https://github.com/jborean93/smbprotocol/issues/289#issuecomment-2396040117.
+                    command = header["command"].get_value()
                     session_id = header["session_id"].get_value()
-                    if session_id == 0xFFFFFFFFFFFFFFFF:
+                    if session_id == 0xFFFFFFFFFFFFFFFF or (session_id == 0 and command == Commands.SMB2_LOGOFF):
                         session_id = request.session_id
 
                     # No need to waste CPU cycles to verify the signature if we already decrypted the header.
@@ -1378,7 +1382,6 @@ def _process_message_thread(self):
                     with self.sequence_lock:
                         self.sequence_window["high"] += credit_response
 
-                    command = header["command"].get_value()
                     status = header["status"].get_value()
                     if command == Commands.SMB2_NEGOTIATE:
                         self.preauth_integrity_hash_value.append(b_header)