Book Image

Hands-On MQTT Programming with Python

By : Gaston C. Hillar
Book Image

Hands-On MQTT Programming with Python

By: Gaston C. Hillar

Overview of this book

<p>MQTT is a lightweight messaging protocol for small sensors and mobile devices. This book explores the features of the latest versions of MQTT for IoT and M2M communications, how to use them with Python 3, and allow you to interact with sensors and actuators using Python.</p> <p>The book begins with the specific vocabulary of MQTT and its working modes, followed by installing a Mosquitto MQTT broker. You will use different utilities and diagrams to understand the most important concepts related to MQTT. You will learn to make all the necessary configuration to work with digital certificates for encrypting all data sent between the MQTT clients and the server. You will also work with the different Quality of Service levels and later analyze and compare their overheads.</p> <p>You will write Python 3.x code to control a vehicle with MQTT messages delivered through encrypted connections (TLS 1.2), and learn how leverage your knowledge of the MQTT protocol to build a solution based on requirements. Towards the end, you will write Python code to use the PubNub cloud-based real-time MQTT provider to monitor a surfing competition.</p> <p>In the end, you will have a solution that was built from scratch by analyzing the requirements and then write Python code that will run on water-proof IoT boards connected to multiple sensors in surfboards.</p>
Table of Contents (9 chapters)

Forcing the TLS protocol version to a specific number

It is good practice to use the highest possible TLS protocol version. By default, a Mosquitto server accepts TLS 1.0, 1.1, and 1.2. If all the clients are capable of working with the highest TLS protocol version supported by Mosquitto, we should force Mosquitto to use only the highest version. This way, we make sure that we won't be vulnerable to attacks on previous TLS versions.

Now, we will make the necessary changes in the configuration file to force the use of TLS 1.2. If you are running the Mosquitto server in a Terminal window in macOS or Linux, press Ctrl + C to stop it. In Windows, stop the appropriate service.

Go to the Mosquitto installation directory and open the mosquitto.conf configuration file.

In macOS, Linux, or Windows, add the following line at the end of the configuration file:

tls_version tlsv1.2