This commit implements rate limitation for the TCAT commands Present PSKd Hash TLV (0x10), Present PSKc Hash TLV (0x11) and Present Install-code Hash TLV (0x12) to prevent password guessing attacks. It also removes the TCAT command Request PSKd Hash TLV (0x14), to prevent offline password guessing attacks with a single Hash value retrieved from the device. Note: The commit does not remove the Request PSKd Hash TLV implementation in the Python commissioner such that the non-existence of the command TLV can still be tested.
TCAT Commissioner (BBTC) Client
Overview
This is a Python implementation of a Bluetooth-Based Thread Commissioning (BBTC) client, based on Thread's TCAT (Thread Commissioning over Authenticated TLS) functionality.
Installation
If you don't have the poetry module installed (check with poetry --version), install it first following the official installation instructions.
For example, if pipx is available:
pipx install poetry
If pipx is not available, it can be installed for Linux/Windows/MacOS following the pipx installation instructions.
Then, install this project using Poetry:
poetry install
This will install all the required modules to a virtual environment, which can be used by calling poetry run <COMMAND> from the project directory.
Note: Installation on Windows requires that Build Tools for Visual Studio C/C++ be installed first.
Usage
To see the supported commandline arguments of BBTC client, use:
poetry run python3 bbtc.py --help
In order to connect to a TCAT device, run:
poetry run python3 bbtc.py {<device specifier> | --scan}
where <device specifier> can be:
--name <NAME>- name advertised by the device--mac <ADDRESS>- physical address of the device's Bluetooth interface
Using the --scan option will scan for every TCAT device and display them in a list, to allow selection of the target.
For example:
poetry run python3 bbtc.py --name 'Thread BLE'
The application will connect to the first matching device discovered and set up a secure TLS channel. The user is then presented with the CLI.
Usage with a specific TCAT Commissioner identity
The TCAT Commissioner's certificate specifies what permissions it has obtained for specific features of managing a TCAT Device. By default, the identity in the auth directory is used. In order to use a different TCAT Commissioner certificate (identity), use the --cert_path argument, as follows:
poetry run python3 bbtc.py --cert_path <certs-path> {<device specifier> | --scan}
where <certs-path> is the directory where the private key, certificate, and CA certificate(s) of the TCAT Commissioner are stored.
For example to use a pre-configured identity CommCert2 (related to Thread certification tests):
poetry run python3 bbtc.py --cert_path ./auth-cert/CommCert2 --name 'Thread BLE'
The auth-cert directory contains some other identities too, for testing purposes. Refer to Thread TCAT test plan documents for details.
See GENERATING_CERTIFICATES.md for details on generating own certificates.
TCAT Commissioner CLI Commands
The application supports the following interactive CLI commands:
help- Display available commands.commission- Commission the device with current dataset.thread start- Enable Thread interface.thread stop- Disable Thread interface.hello- Send "hello world" application data and read the response.exit- Close the connection and exit.dataset- View and manipulate current dataset. Usedataset helpfor more information.