Book Image

MQTT Essentials - A Lightweight IoT Protocol

5 (1)
Book Image

MQTT Essentials - A Lightweight IoT Protocol

5 (1)

Overview of this book

This step-by-step guide will help you gain a deep understanding of the lightweight MQTT protocol. We’ll begin with the specific vocabulary of MQTT and its working modes, followed by installing a Mosquitto MQTT broker. Then, you will use best practices to secure the MQTT Mosquitto broker to ensure that only authorized clients are able to publish and receive messages. Once you have secured the broker with the appropriate configuration, you will develop a solution that controls a drone with Python. Further on, you will use Python on a Raspberry Pi 3 board to process commands and Python on Intel Boards (Joule, Edison and Galileo). You will then connect to the MQTT broker, subscribe to topics, send messages, and receive messages in Python. You will also develop a solution that interacts with sensors in Java by working with MQTT messages. Moving forward, you will work with an asynchronous API with callbacks to make the sensors interact with MQTT messages. Following the same process, you will develop an iOS app with Swift 3, build a website that uses WebSockets to connect to the MQTT broker, and control home automation devices with HTML5, JavaScript code, Node.js and MQTT messages
Table of Contents (16 chapters)
MQTT Essentials - A Lightweight IoT Protocol
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Forcing the TLS protocol version

It is a good practice to use the highest possible TLS protocol version. By default, Mosquitto 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 to the previous TLS versions.

Now, we will make the necessary changes in the configuration file to force the usage of TLS 1.2. In case 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 lines at the end of the configuration file:

    tls_version tlsv1.2 

We specified the tlsv1.2 value for the tls_version option to make Mosquitto work only with TLS 1.2. Any client that uses an earlier TLS version...