Check BTS for the NC List [$50]

Created by: He3556

If the "unsupported flag" (see https://github.com/SecUpwN/Android-IMSI-Catcher-Detector/issues/100#issuecomment-67913431) is not set, we still need to check if every BTS is providing a NC (Neighboring Cell) list. The NC list is used to provide information to the cell phone to select a new antenna if there is an antenna with better signal reception than the currently connected one. But the cell phone doesn't need to scan or connect to all BTSs to get this info and saves energy.

Our code is already reading the NC list with API calls and other methods. But there might be some phones that do not support this (like many Samsungs), so there will be an empty list. If the list is empty, then we need to set the unsupported flag=1. In the logcat you see when the phone is polling for the information. And on the menu you see the NC list under Cell Information, on those phones providing it.

If the flag = 0 and the NC list of the currently connected Cell is empty, then we have a positive detection of a suspicious BTS. Most IMSI-catchers doesn't provide an NC list or they manipulate it. (Finding manipulations will be the next task to test for.) In particular, if we find a cell-id (CID) that is not in the OCID DB, this check is important. Thus we should run this test immediately.

There is a $5 open bounty on this issue. Add to the bounty at Bountysource.