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Hacking a VW Golf Power Steering ECU

blog.willemmelching.nl

81–90 of 174 posts

Re: Hacking a VW Golf Power Steering ECU

#81

> The electronics seemed to be fabricated using bare dies attached to some substrate, probably to lower cost and improve reliability at higher temperatures. The board is made up of two parts, a low-power part with the CPU and CAN transceivers, and some high-power part with 6 MOSFETs forming a three phase H-Bridge. > https://blog.willemmelching.nl/images/vw/IMG_3181.jpg It doesn't really look cheap to me (large machin…

Yeah, it looks like it's extremely optimised for reliability. The construction reminds me of some of the space stuff I'd seen made by a company I worked for (it was all done before my time though). It probably wouldn't be incredibly expensive in this case (automotive) because all the wire bonding and tab welding can be automated, but clearly cost isn't the main concern behind the design!

Automotive has quite broad temperature and vibration requirements and is supposed to work for 15 years+ so it makes sense to pick something like this.

Re: Hacking a VW Golf Power Steering ECU

#82
post #10

As cool as this is, I will never EVER hack/jailbreak car steering. I can't put my faith in unsupported (non-OEM may be a better term for it) software keeping me safe. I watch the tesla autopilot videos of them totally messing up and that is fully supported but still failing too much. But cool POC for sure.

What did you get your elevator operator for Christmas?

Well, presumably you're not letting your neighbor down the hall flash your elevator's firmware. He/she said non-OEM.

Re: Hacking a VW Golf Power Steering ECU

#84

Earlier quoted context omitted.

> Excuse me, how do you envision the use of one-time pads in the real world? You load up as much one-time pad as you will have data to transmit - sometimes hundreds of MB of key if required. Storage is cheap.

Hundreds of Megabytes? That’s a big number to you? Did you step out of a time warp from 1990? Also you are surprisingly quite clueless about basic crypto if you think storage is the biggest issue with practically using one time pads (though it is indeed one). I’m pretty sure even the Wikipedia article can explain this so no reason to spoon feed it here.

> Hundreds of Megabytes? That’s a big number to you?

If you only have a hundred MB of data to send… a hundred MB of key is sufficient to use as a one-time pad.

Until digitisation the military literally did encryption over radios using physical pads - everyone carried a big one-time-pad (just a few tens of KB though). It was done as a lookup table rather than an XOR though.

Re: Hacking a VW Golf Power Steering ECU

#85
post #75

Earlier quoted context omitted.

But you did say this: > Putting a computer between my foot/hands and the physics unfolding in front of me is a total non-starter. Which ABS does, there's literally a computer in between your inputs and the 'physics'. So which is it? There was a time when ABS was not considered a simple problem. They had to invent it for the Concorde. > You can typically disable these pretty easily (pull fuse/drive system configure).…

Allow me to be more precise: I do not want to operate a vehicle wherein the exclusive means of conveying my control inputs to the final destinations is via a computer. Some limited augmentations to existing direct inputs are acceptable in my view.

Is the phrase you are looking for "drive by wire"?

Re: Hacking a VW Golf Power Steering ECU

#86
post #18

Earlier quoted context omitted.

What does it mean to permanently brick the hardware?

Most ECUs have diagnostic messages that can read/write memory. This is often intended to be controlled by what "mode" the ECU is in (manufacturing/engineering/production/dealer-service), but these aren't always well tested or properly implemented controls. Fuzzing these leads to weird behavior and state machines with not-well-tested transitions. Whether you can reset these to a known state is ECU specific, and often…

And sometimes it will require gear that isn't publicly available.

Re: Hacking a VW Golf Power Steering ECU

#87
post #31
post #21

Earlier quoted context omitted.

Do you consider an automatic emergency break as less reliable than it helps? Because we do have a lot of numbers on cars were there is a computer in-between. Which should indicate to me that it is safer to drive with one instead of without one. Like just yesterday (I'm driving a new car) I thought about emergency breaking automatic vs. manual and I actually feel safer knowing that the car can potentially break faster…

> I thought about emergency breaking automatic vs. manual and I actually feel safer knowing that the car can potentially break faster. For me, the knowledge that some other engineer designed a system that is a complete black box (from my perspective), which can arbitrarily stop my car with incredible braking force is terrifying. What happens if the emergency braking system decides to have a bug while you are exiting…

I've written about this before on HN, I had a late model C class Mercedes that decided to emergency brake on the surface of a small bridge sending the car into a spin, the same thing happened in a turn when there was a large sign present.

In both cases the error seems to have been related to the radar picking up a return and interpreting that as an imminent frontal collision when there was absolutely no reason for that. I had the vehicle checked out, they said it was performing to spec so I sold it. No more Mercedes for me.

Re: Hacking a VW Golf Power Steering ECU

#88
post #61

Earlier quoted context omitted.

Reintroducing border control would be a good 1st step. But gods forbid movement of „goods“ is endangered :)

I know of no state that controls their outbound goods, so it'd be on the countries benefiting from this to get more strict, not gonna happen.

Here in Lithuania we’re still checking cars leaving to Belarus to make sure they ain’t stolen. Random car papers checks on Poland/Lithuania border is still a thing too. Both to make sure Porsche stolen in Berlin last night don’t end up in Moscow 24 hours later.

Unfortunately it’s hard to check every boot for stolen headlights and steering wheels without border control

Re: Hacking a VW Golf Power Steering ECU

#89

Earlier quoted context omitted.

> Do you mean the XOR encryption used? As someone working on the embedded linux(!= than embedded MCU) side i was very surprised to find such a crude "encryption" scheme employed. I'm not a cryptographer - but I don't think there's anything wrong with XOR encryption, and I'm not sure why you're putting it in scare-quotes - XOR with a sufficiently large key is absolutely fine, and with a one-time pad is unbreakable. XO…

> XOR with very large keys is how critical military encryption systems such as radios work. Is it that large keys are factors of very large prime numbers so that to know the keys you will need a very powerful computer?

There are only two factors of any prime number, large or otherwise: 1 and the number.

But even correcting to what you must have meant to suggest doesn't make sense.

Re: Hacking a VW Golf Power Steering ECU

#90

Earlier quoted context omitted.

Yes you can programatically generate a key.

And we call that a stream cipher, not "XOR encryption", even though it uses a XOR operation. You're programmatically generating a keystream , which is not the same thing as a key.

See, this is why we can't have secure things.
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