This might be a silly question, but with my inexperience I am not sure where to start looking.
I want a file server that would first authenticate a user and check that the user is permitted to access the specific file he/she is looking for before serving the file through some secure method (e.g. FTPS).
What software and/or technologies should I look into? I imagined such a setup might be called an "access restricted file server", but Googling the expression has not been very fruitful.
This is for a hobby so I don't have a very large budget. I have a reasonably modern laptop running Ubuntu that I could dedicate for this purpose. On the other hand, I don't want to rule out web services like Google App Engine etc.