Hi,
inspired by this discussion, I started to port / implement a Timebased On-Time Password (TOTP, as defined per RFC 6238) algorithm as library for the PLC.
A very early first version is finished right now, and I decided to make it public available in my repository :
Please note, that I’ve done just some basic tests until now, so I can’t guarantee anything … but at least those basic tests looked good so far 
What does the the library support?
- 6-digit numeric time-based one time password compatibility with standard authenticator apps (like Google or Microsoft Authenticator)
- integrated shared secret generation based on two string informations or one string information plus a certificate
- otpauth link generation for the shared secret exchange with the authenticator app
- usable for two-factor authentication together with AR UserRole system (not implemented, that’s just a use-case example)
- also usable for some kind of “password of the day” use-cases (but then not with standard authenticator apps, as they just support 30s valid passwords)
In the sample task showing the basic usage of the library, additionally a QRcode can be displayed directly via the AR embedded webserver (there’s a 2nd library named WsQRlib used, that is also available in the repository).
Everything is under MIT license.
Happy coding and best regards!
@patrick.tanner, maybe it’s interesting for your use-case.
, so it may take some time until I can test it.