I've a number of kiosk computer implemented my company's application which use firefox as front end user interface. All the users have to do is just staying on firefox to do their job. However when they click on firefox's "File" Menu and click open or save page as, the file dialog show up so they can explore the file system including my back end application files and mapped network drive which I seriously want to hide for security reason. I've found methods to hide those in nautilus using the .hidden file but it doesn't work in file/save dialog.
As I'm very new to Linux, I created user accounts for them as standard users and I think all user has read access to file system by default (and should they need it to make operating system and application run properly?) Then can't I take read permission out from them? Please correct me if I'm wrong.
So can i just prevent users from open file dialog? An approach i can think now is that are there any file system or library file that handle those file/save dialog? so that i can edit permission of them and the users will get permission denied dialog instead.
If not possible, any suggestion to hide file system and mapped network folder in file dialog? Please help every suggestion will be appreciated. Thanks in advance.