Auth MFA

This section contains methods commonly used for Multi-Factor Authentication (MFA) and are invoked behind the supabase.auth.mfa namespace.

Currently, we only support time-based one-time password (TOTP) as the 2nd factor. We don't support recovery codes but we allow users to enroll more than 1 TOTP factor, with an upper limit of 10.

Having a 2nd TOTP factor for recovery frees the user of the burden of having to store their recovery codes somewhere. It also reduces the attack surface since multiple recovery codes are usually generated compared to just having 1 backup TOTP factor.