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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

#21

Post by Veritio »

bob1029 wrote: post #15
marcodiego wrote: post #11

Power Steering ECU... this things determines how the driving wheel makes the car turn. Safety issues must be considered.

I will never purchase a vehicle for my own purposes that does not use hydraulics for brakes and steering. Putting a computer between my foot/hands and the physics unfolding in front of me is a total non-starter.

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.

In the brochure of my mother's potentially future car, it actually advertise emergency breaking with emergency steering to drive left or right. I also found that quite good to have as it should be able to determine much faster if it can evade and where to evade.

Or do you mean this different?

Re: Hacking a VW Golf Power Steering ECU

#22

Post by markus_zhang »

chrisseaton wrote: post #6
ptsneves wrote: post #3

Earlier quoted context omitted.

> One interesting difference and trend in automotive control modules (also mentioned in Willem's fantastic write-up) is that many EU modules started adding signature checking and encrypted updates in the late 2000s 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. On the other hand i reckon t…

> 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?

Re: Hacking a VW Golf Power Steering ECU

#25

Post by chrisseaton »

markus_zhang wrote: post #22
chrisseaton wrote: post #6

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?

XOR with a one-time pad doesn't work off factors of large numbers - you're thinking of asymmetric encryption there. You literally just XOR each plain text byte with a key byte.

Re: Hacking a VW Golf Power Steering ECU

#26

Post by ugjka »

lillecarl wrote: post #13
bri3d wrote: post #8

Earlier quoted context omitted.

This is unlikely to be related to encryption but just protectionism on an older vehicle. Generally speaking, until very recently (like 1-2 years ago), non-immobilizer related adaptation processes are just a matter of finding the correct UDS remoteRoutine to invoke, and aren't cryptographically protected at all. It's likely that the thing you're missing is the diagnostic documentation for the correct routine invocatio…

Seeing the amount of part theft in Stockholm I understand why they do it. Particularly steering wheels, they steal them and send them to the baltics where they put them in vehicles where the airbag has fired.

Then you solve the problem in the baltics, not use it as excuse to turn your cars into "iphones"

Re: Hacking a VW Golf Power Steering ECU

#27

Post by formerly_proven »

> 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 machined surfaces on the cast aluminium casing, two ceramic PCBs, everything connected with wire bonding, even the motor windings and the external connector, which means that at least those bonds are carried out on an almost completely assembled product; also look at the sheer size of the motor bonds) but it does look very reliable - everything is bonded or welded, zero connectors, no fasteners, all solid state.

Re: Hacking a VW Golf Power Steering ECU

#28

Post by birken »

Veritio wrote: post #23

While I find this quite interesting, a street is not a lab. He should not do this on any public road and potentially he broke already some law.

The driver is always responsible for what their vehicle does. As long as the driver can override the steering (which they can), then there is really nothing to be concerned about. This is the same for cars using openpilot, or Tesla's self driving systems or any other steering assistance features.

Re: Hacking a VW Golf Power Steering ECU

#29

Post by kyazawa »

bob1029 wrote: post #15
marcodiego wrote: post #11

Power Steering ECU... this things determines how the driving wheel makes the car turn. Safety issues must be considered.

I will never purchase a vehicle for my own purposes that does not use hydraulics for brakes and steering. Putting a computer between my foot/hands and the physics unfolding in front of me is a total non-starter.

With EPAS your steering wheel still physically steers the wheel via the rack and pinion gears.

With ABS and ESC, most cars on the road today have a computer involved in the braking system. It seems pretty safe.

Re: Hacking a VW Golf Power Steering ECU

#30

Post by pd0wm »

markus_zhang wrote: post #24

One question: in part 2 it shows that Ghidra is able to produce disassembly from machine code, does that mean Ghidra knows the instruction set V850 uses?

Ghidra uses an intermediate language called p-code. When defining the CPU opcodes (and how to parse them), you also write a small snippet of p-code that represent that instruction. This makes the decompiler architecture agnostic.

Example: https://github.com/NationalSecurityAgency/ghidra/blob/master...

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