Page History

...

Kafka currently supports non-configurable SASL extensions in its SCRAM authentication protocol for delegation token validation.

It would be useful to provide configurable SASL extensions for the OAuthBearer authentication mechanism as well, such that clients could attach arbitrary data for the principal authenticating into Kafka. Even though the JWT token standard supports customizable fields (in the form of claims), there are use cases where the client is unable to add additional ones (e.g: Kafka client receives a signed JWT token from a third-party).

This way, a custom principal can hold information derived from the authentication mechanism, which could prove useful for better tracing and troubleshooting, for example. This can be done in a way which allows for easier extendability in future SASL mechanisms.

...