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Hacking a VW Golf Power Steering ECU

blog.willemmelching.nl

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Re: Hacking a VW Golf Power Steering ECU

#141

Post by garaetjjte »

captainmuon wrote: post #134
formerly_proven wrote: post #27

> 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…

I'm really surprized this is reliable (of course they know what they are doing). Maybe because all the wirebonds to the dies are encased in epoxy (?) and the other bonds are so thick. Even then I would be worried they would snap off or lift their pads. I wasn't directly involved but I still have nightmares about wirebonding. For a large partice physics experiment, we bonded electronics to silicon (wafer) sensors. Tho…

This isn't epoxy, it's some sort of sticky soft coating. Wirebonds looks fragile to me too, but after all every packaged chip have wirebonded pins, so at least it shouldn't be worse.

Re: Hacking a VW Golf Power Steering ECU

#142

Post by froh »

j4hdufd8 wrote: post #17
blincoln wrote: post #9

This may go without saying, but a word of caution for anyone who wants to try this themselves: doing any sort of automated scanning of ECU hardware (e.g. the equivalent of trying to find undocumented opcodes in a CPU) stands a good chance of bricking the hardware (permanently), so plan to buy several of them if you want/need to go that route.

What does it mean to permanently brick the hardware?

Is a colloquialism for breaking it beyond repair. The origin is that you turn the fancy expensive electronic device into a heavy paperweight like block, just like a brick.

For the "how" of what happens inside so it can't be repaired please see the sibling comments.

Re: Hacking a VW Golf Power Steering ECU

#144

Post by monocasa »

chrisseaton wrote: post #130
monocasa wrote: post #126

Earlier quoted context omitted.

That's not quite what I'm seeing, instead that what I believe you're talking about (Morse code over open air with a Diana cipher backed by one time pads) were pretty much exclusively used by special forces in Vietnam. The issues with key distribution inherent in one time pads otherwise got in the way of cross team cooperation too much since each pad would only exist in two places (the spec ops team, and a major base…

> That's not quite what I'm seeing ... it wasn't actually deployed in the general case I'm was literally trained in the British variant of technique I'm describing. There's a wikipedia article about it, and it's referenced from this cryptography wiki's one-time-pad page. Other countries used similar systems. https://en.wikipedia.org/wiki/BATCO https://cryptography.fandom.com/wiki/One-time_pad

So if I'm understanding BATCO correctly, there's an average key reuse by a single sender after 13 messages because of the how the traffic key rotation selects a row? That, combined with the sense I'm getting that the cipher sheets were distributed widely (auth tables imply multiple senders using the same cipher sheet at the same time) seems to imply broad reuse of key rows, making it a pad, but not a one time pad. Do my assumptions filing in the blanks line up?

I'll give it that's it's definitely way better than DRYAD, which is pretty universally not considered a OTP because of the much greater key reuse (like how auth uses the same cipher tables as encrypt, leaking tables). So it boils down to the practical use case on whether it falls into OTP.

Re: Hacking a VW Golf Power Steering ECU

#145

Post by chrisseaton »

monocasa wrote: post #144
chrisseaton wrote: post #130

Earlier quoted context omitted.

> That's not quite what I'm seeing ... it wasn't actually deployed in the general case I'm was literally trained in the British variant of technique I'm describing. There's a wikipedia article about it, and it's referenced from this cryptography wiki's one-time-pad page. Other countries used similar systems. https://en.wikipedia.org/wiki/BATCO https://cryptography.fandom.com/wiki/One-time_pad

So if I'm understanding BATCO correctly, there's an average key reuse by a single sender after 13 messages because of the how the traffic key rotation selects a row? That, combined with the sense I'm getting that the cipher sheets were distributed widely (auth tables imply multiple senders using the same cipher sheet at the same time) seems to imply broad reuse of key rows, making it a pad, but not a one time pad. Do…

Yes entire radio net is moving through the shared pad together - so you when you send you consume a bit of the pad, and when someone sends to you they use the next bit of the pad, then you use the next, etc.

A new row per message means you don't re-use between messages (message is something like a sentence).

Each message should be short enough that you don't re-use (a 22-symbol message is already crazy), and you are not allowed to re-use if that means re-using a target symbol, but yes you might slightly re-use within messages if you're being sloppy.

In reality you don't get through the pad very quickly due to the 'compression' of a dictionary for typical parts of messages.

(This is all public info, not disclosing anything here.)

Re: Hacking a VW Golf Power Steering ECU

#146

Post by Prcmaker »

bob1029 wrote: post #75
outworlder wrote: post #62

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.

I've got to agree with this. While I am a fan of some of the assistances that come with vehicles, I am not a fan of the level of assistance some vehicles build in. I've lost power steering and powered brake assistance before (separate occasions), on different vehicles and while technically you still have steering or brakes (not drive by wire) , the loss of mechanical advantage is enough to mean you are effectively a passenger. While modern reliability has reduced the occurrence, the impact when that failure occurrs has only gotten worse.

Re: Hacking a VW Golf Power Steering ECU

#147

Post by throwaway0a5e »

wkearney99 wrote: post #138
throwaway0a5e wrote: post #107

Earlier quoted context omitted.

I couldn't care less. People hacking up things are a rounding error compared to the rest of the motoring public. If your vehicle is capable of meeting the performance expectations of everyone else I don't care what you drive. If your horse and buggy, ebike conversion, etc. can do highway speed and get there within the distance of the merge lane then feel free to ride that crap on the interstate. Likewise I don't see…

ah yes, the casual arrogance of treating other people's lives as just 'rounding errors'. The only fortunate part, I suppose, is the kind of personality disorder that thinks/acts that way is likewise a rounding error.

>ah yes, the casual arrogance of treating other people's lives as just 'rounding errors'.

>The only fortunate part, I suppose, is the kind of personality disorder that thinks/acts that way is likewise a rounding error.

Oh take your hand wringing and shove it.

How many man hours per capita per year are spent operating sketchy modified vehicles?

How many man hours per capita per year are spent driving distracted, intoxicated etc?

While they are not mutually exclusive the former is clearly a rounding error compared to the latter because the slice of the population that is even in a position to engage in it is minuscule compared to the broad mass market appeal of the latter. These people are no more of a concern to society than shark bites.

Re: Hacking a VW Golf Power Steering ECU

#148

Post by Nextgrid »

phkahler wrote: post #95

>> Only try this on an actual car if you know what you’re doing. Even though only two very small patches are made to the model specific calibration values, making changes to your EPS might have unintended consequences. The author has no idea what he's doing, or more specifically what hazards might be lurking right under his nose. I worked in EPS for 6 years and it's all really cool stuff right up until you download c…

> are all protections still in place when taking an external command

Diagnostic-specific commands are often restricted when the vehicle is in motion. On VW I remember that any "write" command such as an actuator test being declined even for "innocent" stuff such as lights or power windows on the body control module.

Re: Hacking a VW Golf Power Steering ECU

#149

Post by Nextgrid »

londons_explore wrote: post #135
phkahler wrote: post #95

>> Only try this on an actual car if you know what you’re doing. Even though only two very small patches are made to the model specific calibration values, making changes to your EPS might have unintended consequences. The author has no idea what he's doing, or more specifically what hazards might be lurking right under his nose. I worked in EPS for 6 years and it's all really cool stuff right up until you download c…

I have a totally stock EPS that will just apply random full torque left or right if the battery voltage drops below ~10 volts. One would imagine that's a scenario they tested for, but apparently not! It happens very easily on my car when all the electrics are turned on for a few hours while driving with low revs, like driving on a cold dark day on a 40mph road. The first time I did it, my thumb was dislocated because…

Could a higher capacity battery help?

Re: Hacking a VW Golf Power Steering ECU

#150

Post by Nextgrid »

C19is20 wrote: post #131
olivermarks wrote: post #94

Earlier quoted context omitted.

My concern is that all vehicles are becoming more and more surveilled, transmitting hugely personal data. Once level 4 centralized control is possible I predict pre permissioned requested travel will quickly follow. We urgently need a new generation of very basic transportation devices. The 3rd world relies on Toyo HiLuxes etc which are still easy to keep running. LandRover used to be all over the third world because…

Gdpr could be your friend.

GDPR is not enforced enough and it's very hard to get it enforced. Data protection authorities are completely useless at handling complaints from my experience.
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