MQTT client authentication using a password

Authenticate the Username using the client password. We can authenticate the client using a different identity to the identity used to authorize the client to publish and subscribe to topics.

The telemetry (MQXR) service uses JAAS to authenticate the client Username. JAAS uses the Password supplied by the MQTT client.

The IBM MQ administrator decides whether to authenticate the Username, or not to authenticate at all, by configuring the MQTT channel a client connects to. Clients can be assigned to different channels, and each channel can be configured to authenticate its clients in different ways. Using JAAS, we can configure which methods must authenticate the client, and which can optionally authenticate the client.

The choice of identity for authentication does not affect the choice of identity for authorization. You might want to set up a common identity for authorization for administrative convenience, but authenticate each user to use that identity. The following procedure outlines the steps to authenticate individual users to use a common identity:

1. The IBM MQ administrator sets the MQTT channel identity to any name, such as MQTTClientUser, using IBM MQ Explorer.
2. The IBM MQ administrator authorizes MQTTClient to publish and subscribe to any topic:

    setmqaut -m QM1 -t q -n SYSTEM.MQTT.TRANSMIT.QUEUE -p MQTTClient -all +put
   setmqaut -m QM1 -t topic -n SYSTEM.BASE.TOPIC -p MQTTClient -all +pub +sub
   

3. The MQTT client application developer creates an MqttConnectOptions object and sets Username and Password before connecting to the server.
4. The security developer creates a JAAS LoginModule to authenticate the Username with the Password and includes it in the JAAS configuration file.
5. The IBM MQ administrator configures the MQTT channel to authenticate the UserName of the client using JAAS.