WebAuthN: "prf" extension support #7238
Description
The PRF extension to WebAuthN allows deriving secret keying material from a given WebAuthN credential.
At least Chrome seems to support it behind a flag (there's a demo on the linked reference). According to some initial testing, neither Safari nor Firefox on macOS do.
Support seems to depend on both the browser and OS (as at least Firefox on macOS leans to an OS-provided API for its WebAuthN implementation).