I can use `mod_auth_basic` or `mod_auth_digest` for authenticating users.
I can sign in or sign out using mod_auth_form.
How to sign up when using the Apache authentication system?
I guess that module has to write to dbm password files.
Just to be clear, I want to use `mod_authn_socache` to maintain the cache.
Is there any module or mechanism to do this?