Redmine

Is it possible to have synchronized Redmine and Subversion (without Apache) ?

I use Nginx as webserver, so I'm connecting to SVN via protocol svn://domain/repo. (because there is no dav_svn support for Nginx)
User permissions are saved in Authz file and passwords are saved via SASL.
Everything works fine, I can also browse repository in Redmine.

But when I add user to Redmine project which have assigned repository, I need also set user permissions for that repository (automatically).
So user will be able to checkout from SVN by Redmine username/password.
Is that possible to achieve with Redmine?

I was thinking about LDAP server, but I don't think that Redmine will properly set repository permissions to LDAP server.

Thank you