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submitted 10 months ago by [email protected] to c/[email protected]
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[-] [email protected] 15 points 10 months ago

They can detect that too - at least, they can detect the common software. You might be able to do it with a custom QEMU setup but good luck guaranteeing that for your exam.

[-] [email protected] 29 points 10 months ago* (last edited 10 months ago)

I used to be a reseller of this highly specialized navigation software. The licensing was handled via hardware fingerprinting of the harddrive. I'm not 100% sure on how it worked, but it grabbed some raw data off of the boot device, and from that generated a fingerprint. This fingerprint was then sent to the guys who made the software, and they would then send us a license key and a hefty bill. The license key only worked with syatems running off of that particular harddrive. If a customer had a harddrive failure, we had to send them the actual harddrive for them to verify, so they would issue a free key to whichever replacement drive was used.

I did a lot of experimenting with that software. It was linux based and very tweakable, but the licensing part of it was a bit of a mystery. I managed to crack it through some surprisingly simple out-of-the-box thinking, but one limitation I could never figure out how to circumvent was its refusal to generate a fingerprint from virtual drives.

For starters, it only worked with drives registering as /dev/hdX or /dev/sdX. Anything outside of that and it wouldn't generate a fingerprint.

This was especially frustrating when a well-paying customer offered a nice bonus if we could install it on a macbook for him. After a few days of tweaking I managed to install and run it, only to discover that fingerprinting the drive couldn't be done due to the device node being/dev/nvmeSomething. And after avfew more days of hacking I managed to fake that too, and they outright refused to issue a license due to them not wanting to support our unofficial hacks.

Where was I going with this? Oh, right, vmware.. i never managed to get it to run in vmware. We had this other well paying customer who wanted the ability to alt-tab between the software and Windows. Unfortunately, any fingerprinting done from within vmware, regardless how I set up the storage, resulted in a fingerprint file with no data.

Fun fact: the software ui was written in raw xlib. I got to know the owner and lead dev fairly well, and he hinted that the codebase was a complete mess to the point where something as simple as an input dialog for a config option I recommended was A LOT of work.

[-] wheeldawg 3 points 10 months ago

I would love to know how that's possible.

[-] [email protected] 10 points 10 months ago

The easy way involves looking at the devices and drivers you have installed. Things like a VirtualBox display or a SPICE guest driver are dead giveaways. next, they might look at your processor and see if it has as many cores as it should, but that's more involved.

[-] wheeldawg 1 points 10 months ago

Holy shit why is it even getting anywhere near that nosy? I didn't know it was anything like that. And I even worked for them for a little while.

[-] [email protected] 0 points 10 months ago* (last edited 10 months ago)

Holy shit why is it even getting anywhere near that nosy?

Because it also serves as an anti-cheat...in the most literal sense. It is trying to make sure students can't cheat by having other things open like answer pages or Google.

[-] wheeldawg 1 points 10 months ago

Oh, duh. That seems a little obvious in retrospect. But damn, they go pretty harsh then.

[-] [email protected] 1 points 10 months ago* (last edited 10 months ago)

The qualifications industry is heavily reputation based. If they get a reputation for letting cheaters slide, their reputation tanks among employers and therefore no one will want that qualification.

And these qualifications are expensive as hell too.

this post was submitted on 12 Sep 2023
1192 points (97.9% liked)

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