emqx4.3/changes/ee/feat-13810.en.md

Add clinet-info authentication.

Client-info (of type cinfo) authentication is a lightweight authentication mechanism which checks client properties and attributes against user defined rules. The rules make use of the Variform expression to define match conditions, and the authentication result when match is found. For example, to quickly fence off clients without a username, the match condition can be is_empty_val(username) associated with a check result deny.