Nauthilus
Nauthilus is a general purpose authentication service written in Go. It is designed to work as a central place where all kinds of
authentication requests are handled. No matter if you need to authenticate users from a mail server or a web page.
Services are connected to Nauthilus.
Screenshots
This is an example of Nauthilus, how it is integrated in Dovecot and Roundcube.
Login screen
Entering TOTP code
Official website
The documentation is found on https://nauthilus.org.
The documentation itself is another project at https://github.com/croessner/nauthilus-website.
Feel free to make it better! :-)