How to check if Android Permission is actually being used?

Question

I am maintaining one existing (very-huge, very-sensitive) Android Application.
The other day, I have received an email from my client that, the Application mig

Answer 1

There is a group at Berkeley that wrote a paper about Android permissions. They talk about over-permissions and developed a tool called Stowaway that would analyze your APK for unused permissions. The analysis was based on the app's API calls and their own mapping of the permissions needed for each API call (see the paper for details). The tool throws a flag if there is a permission in the manifest that is not mapped to any of the API calls found in the APK.

For a while, a web-based version of the tool was available at http://www.android-permissions.org/, but it is from the Gingerbread era and was never updated. The page now suggests using PScout.

PScout does a better job than Stowaway at generating the permission maps. However, PScout does not include an APK analyzer, so you will have to manually compare the mappings they provide with API calls made by your app. Unfortunately, if you're interested in maps for versions beyond 5.1.1, you'll have to generate them yourself using the provided PScout code and your own Framework source.

You might also check out the various APK analyzers here to see if they include the functionality you are looking for.