Android Declassification Infrastructure

1. Android Declassification Infrastructure Matan David Yuval Evron Project Advisor: Roei Schuster

2. Smart Phones • Go with us everywhere we go. • Getting richer in capabilities and sensors. • We install different applications on our phone. • An over-privileged application could pose a serious threat to us as end users.

3. Android OS • Unveiled by Google at 2007. • Based on the Linux OS. • Used by 50% of smartphone owners in the U.S. • Over 400 million Android devices in use by February 2012. • Over 1,000,000 Android devices activated every day.

4. Android Permissions • Enables apps to “communicate” with different hardware components (Camera, SD Card..) • <uses-permission android:name= "android.permission.CAMERA"/> • Not very fine grained. • Each permission grants access to not only one service, but to several.

5. Our Project • Does not involve changing the OS infrastructure itself. • Identify the most commonly used and most vulnerable permissions . • Subdivide them into smaller, finer grained permissions. • A “Declassifier”.

6. Project Goals • Enable much safer Android programming. • Applications utilizing our infrastructure will be less privileged and more secure. • No compromise on application functionality. • Make porting of applications as simple as possible.

7. Success Criteria • Try to influence as many applications as possible. • Success will be measured by revising consumer applications, limiting their privileges, while preserving their original capabilities.

8. Implemented Declassifier Services • Android Permission – android.permission.READ_CONTACTS Declassifier Permissions: • my.declassifier.CONTACTS_PHOTO_BY_NAME_PERMISSION • my.declassifier.CONTACTS_PHONE_BY_NAME_PERMISSION • my.declassifier.CONTACTS_ADDRESS_BY_NAME_PERMISSION • my.declassifier.CONTACTS_BIRTHDAY_BY_NAME_PERMISSION • my.declassifier.CONTACTS_EMAIL_BY_NAME_PERMISSION • my.declassifier.CONTACTS_IS_STARRED_BY_NUMBER_PERMISSION • Android Permission - android.permission.WRITE_EXTERNAL_STORAGE Declassifier Permissions: • my.declassifier.EXTERNALSTORAGE_WRITE_FILE_PERMISSION • my.declassifier.EXTERNALSTORAGE_DELETE_FILE_PERMISSION • my.declassifier.EXTERNALSTORAGE_ALL_FILENAMES_PERMISSION • my.declassifier.EXTERNALSTORAGE_CLEAR_ALL_DATA_PERMISSION • Android Permission – android.permission.READ_PHONE_STATE Declassifier Permissions: • my.declassifier.PHONE_STATED_READ_PHONE_TYPE_PERMISSION • my.declassifier.PHONE_STATE_READ_SUBSCRIBER_ID_PERMISSION • my.declassifier.PHONE_STATE_READ_CALL_STATE_PERMISSION • my.declassifier.PHONE_STATE_READ_SIM_SERIAL_NUMBER_PERMISSION

9. Implemented Declassifier Services • Android Permission -android.permission.READ_CALENDAR Declassifier Permissions: • my.declassifier.CALENDAR_EVENT_DATE_BY_TITLE_PERMISSION • my.declassifier.CALENDAR_LOCATION_BY_TITLE_PERMISSION • my.declassifier.CALENDAR_DESCRIPTION_BY_TITLE_PERMISSION • Android Permission -android.permission.RECORD_AUDIO Declassifier Permissions: • my.declassifier.START_VOICE_RECORD_PERMISSION • Android Permission -android.permission.CHANGE_WIFI_STATE Declassifier Permissions: • my.declassifier.TURN_OFF_WIFI_PERMISSION • my.declassifier.TURN_ON_WIFI_PERMISSION • my.declassifier.CONNECT_TO_WIFI_PERMISSION

10. Implementation We broke down our Declassifier into 3 types: • BroadcastReceiver – • The app sends an ordered broadcast, with all the information encapsulated inside an Intent. Intent i = newIntent("com.example.Declassifier. CALENDAR_EVENT_BY_TITLE_ACTION"); i.putExtra("Title",titleNameStr); • The app also supplies a custom BroadcastReceiver which will handle the Declassifier’s result (callback mechanism). • The Declassifier filters out requests which to not satisfy the relevant permissions, and the app filters out returned results from unauthorized sources.

11. Implementation • ContentProvider – • Encapsulates data and provides it to applications through the single ContentResolver interface. • Content is queried: Uri uri = Uri.parse("content://" + AUTHORITY + "/" + BASE_PATH + "/" + GET_EVENT_DESCRIPTION_BY_TITLE); Cursor cursor = cr.query(uri,null,selection,null,null); • A cursor to the content is returned. • The Declassifier checks if the given URI is permitted access (using the path-permission mechanism) and filters out queries that are not.

12. Implementation • Activity - • Pops up a confirmation screen on the service the 3rd party application is trying to access. • The User has the option of granting or denying the application access. • If permission is granted, the calling application uses service as needed. • If permission is denied, the calling application will return appropriate message and end running method.

13. Ported Applications • SMS Popup – For use with the Phone State declassifier • http://code.google.com/p/android-smspopup/ • Auto Answer – For use with the Contacts declassifier. • http://code.google.com/p/auto-answer/ • My Simple Notepad – For use with the External Storage declassifier. • http://code.google.com/p/my-simple-notepad/feeds • Wifi Compass – For use with the Wifideclassifier. • http://code.google.com/p/wificompass/ • GVoiceMail – For use with the Voice Record declassifier. • http://code.google.com/p/gvoicemail/

14. Running Examples - Auto Answer

15. Running Examples - Auto Answer

16. Running Examples - Auto Answer

17. Running Examples - GVoiceMail

18. Running Examples - GVoiceMail

19. Running Examples - GVoiceMail

20. Running Examples - GVoiceMail

21. Running Examples - GVoiceMail

22. Running Examples - wificompass

23. Running Examples - wificompass

24. Running Examples - wificompass

25. Running Examples - wificompass

26. Running Examples - wificompass

27. Running Examples - wificompass

28. Running Examples - wificompass

29. Running Examples - my-simple-notepad

30. Running Examples - my-simple-notepad

31. Running Examples - my-simple-notepad

32. Running Examples - my-simple-notepad

33. Running Examples - my-simple-notepad

34. Running Examples - my-simple-notepad

35. Running Examples - SMSPopup

36. Running Examples - SMSPopup