feat: filter-out known spoofed data

[matejglejtek]

Detect data from RemoteIDSpoofer using analysis of single message container.

Spoofer description.

Check if messages contain spoofed data by checking known traits of spoofed data, like mac address, timestamps, message contents. Save resulting MessageContainerAuthenticityStatus to MessageContainer.

Basic block is the abstract SpooferDetector class that has method calculateSpoofedProbability. Each subclass of SpooferDetector check one part of the MessageContainer, e.g. mac address, timestamp or message of certain type. Method returns probability of data being spoofed between 0 and 1:

• 0 -> real, 0.5 -> cannot decide, 1 -> spoofed

Detectors can return various values of probability. E.g spoofed data always have 0 as first char of mac addr, but real data also can have 0 at start, so if it is zero I used probability of 0.75 that data are spoofed.

The MessageContainerAuthenticator class contains array of these detectors. When container is updated, the authenticator checks it by running all the detectors and counting the score. Then MessageContainerAuthenticityStatus is worked out from the score:

• < max/2 - untrusted; (max/2, max/4*3) - suspicious; > max/4*3 - counterfeit

If detector cannot decide, it returs 0.5 so half of score means nothing could be decided. If score is bigger than half, at least one detector detected suspicious data so i used this as threshold for suspicious status. For counterfeit status I used threshold of more than 3/4 of score.

Used in dronetag/drone-scanner#78.

DT-3038

[albertmoravec]

Very clean 👍

I really appreciate that we are only making a suggestion on authenticity of the data received and do not take any destructive action. I think it is the best way forward.

[marianhlavac]

The end result is great and the architecture seems well thought out.

I'm very sorry for coming with this in such late phase, but I feel that this should be a feature exclusive to Drone Scanner and we should prefer keeping all of the code in Drone Scanner only. But feel free to open a discussion if you disagree.

It will also be necessary to later work with buffer of stored messages, so please let's move this functionality into Drone Scanner and continue the code review there.

[matejglejtek]

It will also be necessary to later work with buffer of stored messages, so please let's move this functionality into Drone Scanner and continue the code review there.

Ok, I moved the functionality to DroneScanner, dronetag/drone-scanner#78, I am closing this PR.