/FAT32-Android

FAT32 modifications to add permissions for Android

Primary LanguageShell

*********FAT32 modifications for Android***********
***************************************************

Author: Gaurav Tungatkar, Nikhil Talpalikar

Description: 
Modifications to the vfat driver in the Linux kernel module to add a permissions
layer to FAT32. This project tries to implement unix style permissions on top of
FAT32.

Rationale: 
Android based smartphones increasingly use FAT32 formatted SD cards for storing
all sorts of data. With virtually no protection provided by FAT32, this opens up
security holes for data corruption. Adding unix style permissions is useful here
because in Android, every application gets a different user id. Each application
can be thought of as a user and unix style user-group-world permissions can help
enforce separation between applications.

Design:
Each folder has a hidden ".permissions" file which stores the mode and uid, gid
information for each file in that folder. Hacks in file open, to read this
special file and file in the permissions. chmod, chown supported, making changes
to entries in the ".permissions" file.
See demo video.