How to configure Apache+WebDav+PostgresSQL authorization?

Question

PostgreSQL

There is an apache server that acts as a webdav server. When accessing a resource through a browser or webdav, the client is asked for a login/password. Now users and passwords are created via htdigest in a file.
At the same time, there is a database on Postgres where data is stored, including users of the system. Instead of passwords, hashes are stored, as expected.
I can not understand how to make authorization using mod_dbd. In all manuals, a simple example that involves storing passwords in cleartext.
How to check the incoming password, taking into account its encryption in the database?