Hi, I am currently about to port a legacy / custom authentication mechanism from 2.3 to 2.4.
Many things have changed in this area, and I have unfortunately not been able to find any valid documentation about this topic.
I have looked here: https://doc.dovecot.org/2.4.4/developers/design/auth_process.html but as far as I can see all the content is about the code design for dovecot 2.3, not 2.4.
Just to mention a few examples: There is not anymore a struct named mech_module, there is no such file as mech.h, and also the API for the central callback functions such as auth_new() and auth_initial() seems to have changed a lot (both arguments and return types).
Maybe a somewhat unfinished version of the documentation can be found on a specific branch?
Thank you, Kristoffer Møllerhøj.