Which file server to choose with secure access and the ability to create temporary accounts and directories?

Question

FTP

Good day.
We need a solution that can give users secure access via the Internet to a file resource, while we need a convenient functionality for registering accounts, when registering, the lifetime of the account and folder to which access will be given should be indicated. It would be nice if access would be without third-party clients (FileZilla), but secure.
SFTP + Radius comes to mind, probably owncloud, but maybe someone else will suggest some other options.