[feat] Add support for MQTT 5 refresh auth

[robertsLando]

Specs: https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Re-authentication

Discussed in #1794

^{Originally posted by sseiber February 26, 2024}
I'm using JWT Token authentication sucessfully by setting the mqtt client properties before connecting:

properties: {
    authenticationMethod: 'OAUTH2-JWT', // for Azure EventGrid
    authenticationData: <auth-token>
}

I need to be able to re-authenticate with the service when the token needs to be refreshed by sending an auth packet:

{
    cmd: 'auth',
    reasonCode: 0x19,
    properties: {
        authenticationMethod: 'OAUTH2-JWT',
        authenticationData: <auth-token>
    }
}

However, I don't see a way to send a specific packet. I'm following an example that uses MQTTnet to provide this functionality (see SendExtendedAuthenticationExchangeDataAsync):
https://github.com/dotnet/MQTTnet/blob/f82d382f23ec8388ed8a33c48b7ede08e2c18622/Source/MQTTnet/Client/MqttClient.cs#L296

Is there a method or standard pattern in mqtt.js for doing this?

[lesmoutonssauvages]

Hello @robertsLando , Facing the same feature needs, any news on this ?

Have you a workaround idea ?

[robertsLando]

You can build and send the packet manually with something like: https://github.com/mqttjs/MQTT.js/blob/main/src/lib/client.ts#L893

[robertsLando]

If anyone is interested in this you could add a bounty for this here: https://gitpay.me

[suraj-mandal]

Hi, can I contribute to this feature as well @robertsLando?

[robertsLando]

@suraj-mandal sure