Azure IoT Hub support library for Mongoose OS

This library provides Azure IoT Hub support for Mongoose OS.

Currently only plain MQTT is supported.

See Azure IoT + Mongoose OS tutorial at https://mongoose-os.com/docs/quickstart/cloud/azure.md

Authentication

Authentication by both SAS token and X.509 certificate is supported. See the Authentication section of the documentation for explanation.

mos azure-iot-setup

The easiest way to setup Azure cloud connection is by using mos azure-iot-setup. Makes sure you have the az CLI tool installed, create an IoT Hub, then run:

$ mos azure-iot-setup --azure-hub-name MY-HUB-NAME --azure-device-id NEW-DEVICE-ID

SAS Token

To use symmetric key authentication, obtain the connection string from the web interface or by using the az CLI utility:

$ az iot hub device-identity show-connection-string --hub-name my-hub --device-id test1
{
  "cs": "HostName=my-hub.azure-devices.net;DeviceId=test1;SharedAccessKey=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="
}

Enable the Azure client and set the azure.cs config setting:

$ mos config-set azure.enable=true "azure.cs=HostName=my-hub.azure-devices.net;DeviceId=test1;SharedAccessKey=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="

X.509 Certificate

To use authentication by an X.509 certificate, upload the certificate and private key files in PEM format on the device and configure azure.host_name, azure.device_id, azure.cert and azure.key:

$ mos put test4.crt.pem
$ mos put test4.key.pem
$ mos config-set azure.enable=true azure.host_name=my-hub.azure-devices.net azure.device_id=test4 \
                 azure.cert=test4.crt.pem azure.key=test4.key.pem

Note: It is possible to store private key in a cryptochip, such as ATECC508A (for example, as described here for Google IoT Core). Just specify azure.key=ATCA:0 to use private key in slot 0 of the chip. [mos azure-iot-setup] supports ATECC508 key storage - just add --use-atca to the setup command above.