smbclient produces 'STATUS_ACCESS_DENIED' error on windows 2016 server

[johnmantios]

I want to write some files to a remote windows file system. When I do it from my local workstation (windows 10) the code is executed correctly without any errors. However, when I try to do the same thing from a windows 2016 server I get a 'STATUS_ACCESS_DENIED' error for that share. For what it's worth, I can map that specific share to the server so I have excluded the possibility of this being a networking issue. I am wondering whether this is a specific smbprotocol version error and if yes how can I change the used protocol version since I use the high-level smbclient interface. If this is not version related, are there any ideas about what might be wrong?

smbprotocol==1.6.2

The code I use for the file writing transaction:

class SMBClient:
    def __init__(self, host: str) -> None:
        self.host = host
        self.base_path = fr"\\{host}"

        self._create_session()

    def _create_session(self) -> None:
        cred_args = {
            "username": os.environ.get("nsa_user"),
            "password": os.environ.get("nsa_pass"),
        }

        smbclient.register_session(self.host, **cred_args)

        del cred_args

    @staticmethod
    def close() -> None:
        smbclient.reset_connection_cache()

    def write_file(
        self,
        path: str,
        file_buff: _io.BufferedReader,
        fmode: str = "ab",
        timestamp: bool = False,
    ) -> None:

        # append timestamp to filename if requested
        if timestamp:
            path_obj = Path(path)
            current_ts = datetime.utcnow().strftime("%Y%m%d")

            new_file = f"{path_obj.stem}_{current_ts}{path_obj.suffix}"
            path = os.path.join(str(path_obj.parent), new_file)

        full_path = os.path.join(self.host, path)
        with smbclient.open_file(full_path, mode=fmode) as fd:
            fd.write(file_buff.read())

smb_client = SMBClient(os.environ.get("ingestion_host"))
smb_client.write_file(
f"{os.environ[config[destination][filename]]}\\{instance_name}{suffix}",
buffer,
"ab",
 False,
 )
smb_client.close()

[jborean93]

I would recommend you install the latest version. But here are some things I recommend you try:

• If you have a working server test your clients with the same credentials and see what works and what doesn't
• Make sure the credentials you are using are actually valid, you can see the Security event logs to see why an auth may have failed
• Update to the latest smbprotocol version, 1.6.2 is a few releases behind

You can always try to hardcode the credentials to rule out any environment differences in your tests.

[jborean93]

Closing as there was no response to the last message.