Fix intermediate session id preauth tracking

On some hosts, the SESSION_SETUP_RESPONSE message that are not complete
may not set the new session id on the response. This causes problems
when the session is finalised as it tries to lookup the session based on
the session id allocated in the last message which won't line up with
any intermediate messages with a session id of 0.

The fix is to not update the session id tracker for the first
SESSION_SETUP_RESPONSE message but rather the last message where the
session id will actually be allocated.

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 1.10.1 - TBD
+
+* Fix pre auth session id tracking if the intermediate token messages return 0 as the session id
+
 ## 1.10.0 - 2022-11-07
 
 * Require Python 3.7 or newer (dropped 3.6)

pyproject.toml

@@ -6,7 +6,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "smbprotocol"
-version = "1.10.0"
+version = "1.10.1"
 description = "Interact with a server using the SMB 2/3 Protocol"
 readme = "README.md"
 requires-python = ">=3.7"

requirements-dev.txt

@@ -7,4 +7,4 @@ pyspnego
 pytest
 pytest-cov
 pytest-mock
-tox
+tox

src/smbprotocol/session.py

@@ -276,6 +276,7 @@ def connect(self):
             raise SMBAuthenticationError("Failed to authenticate with server: %s" % str(err.message))
 
         self.connection.preauth_session_table[self.session_id] = self
+
         in_token = self.connection.gss_negotiate_token
         if self.auth_protocol != "negotiate":
             in_token = None  # The GSS Negotiate Token can only be used for Negotiate auth.
@@ -307,11 +308,11 @@ def connect(self):
             # If this is the first time we received the actual session_id, update the preauth table with the server
             # assigned id.
             session_id = response["session_id"].get_value()
-            if self.session_id < 0:
+            if self.session_id < 0 and session_id:
                 del self.connection.preauth_session_table[self.session_id]
                 self.connection.preauth_session_table[session_id] = self
 
-            self.session_id = session_id
+                self.session_id = session_id
 
             setup_response = SMB2SessionSetupResponse()
             setup_response.unpack(response["data"].get_value())