5 ms·

For what it's worth, most European cars have much more robust immobilizer systems that use actual cryptographic primitives to both obfuscate and authenticate st

by bri3d 4y ago

For what it's worth, most European cars have much more robust immobilizer systems that use actual cryptographic primitives to both obfuscate and authenticate start-release messages. This is for a variety of reasons - a legal and insurance company focus on immobilizer technology through companies like Thatcham Research as well as a more active threat model geopolitically. There are, of course, weaknesses in these cryptosystems, but the documented attack describes an extremely poor system by modern standards.

droopyEyelids 4y ago
What do you think about how the article listed devices being available for all the European manufacturers?
- bri3d 4y ago
  I would love to see a story about one! I don't work in automotive RE, it's only a hobby, so I don't have budget to go find and buy "emergency start" tools like these security vendors do. As far as I am aware: there are All Keys Lost (AKL) immobilizer bypasses for, for example, Volkswagen Immo 5, but not "Emergency Start" bypasses. The difference is the level of access required: AKL bypasses require involved, long term physical access to a car, for example at a shop. They're useful for independent or fly-by-night shops and in a post-theft scenario, but they're not going to boost a car out of a driveway. Meanwhile, Emergency Start bypasses are plain-and-simple theft tools like the fake Bluetooth speaker from the article. All of the VW Immo 5 exploits which I am aware are of the AKL style and revolve around being able to extract cryptographic material (CS/MAC/ImoDat_noKeyMst/ImoDat_noKeySecu depending on who you ask what it's called) from a control module by physically removing it from the vehicle. This is a far cry from tapping the CAN bus at a headlight and injecting an unauthenticated CAN message.
  - avree 4y ago
    What? This is a CAN bus hack, which is a standard that has been in EU cars for longer than US cars. I've worked with KeylessRide and also built my own hardware immobilizer/CANBUS device at a previous startup, and there is zero difference between European cars and American cars for this... By design, all nodes on a CAN network receive all frames, which is the root of the problem. There are some differences in ECU validation, plus whether or not the vehicle supports UDS diagnostics, but these are differences by manufacturer and have nothing to do with the continent the car is being used on.
    - bri3d 4y ago
      Calling something a "CAN bus hack" is like calling something an "Ethernet hack." It's just a bus, it's what's on the bus that matters. European, American, and Japanese cars have completely different immobilizer module cryptography implementations. In this case, the real weakness was that the immobilizer protocol allowed the car to start without message authentication, the CAN-related message injection thing was a sideshow. Generally, European cars have stronger immobilizer implementations. For example, in VW Immo 5, immobilizer messages are encrypted and authenticated using AES with a PRNG-based MAC. At a high level, participating modules need knowledge of a secret AES key in order to encrypt random number seed material. It's symmetric so it's still not perfect, but this type of simple "send one message through a headlight" attack would not be possible on these cars. Update: ah, I see you edited your comment. Yes, it has nothing to do with where the cars are _used_. My point was that European _manufacturers_ tend to have more secure immobilizer implementations, and I will stand by that point.
      - avree 4y ago
        You know that Toyota, the manufacturer here, is a Japanese company, right? European versus American regulations have literally nothing to do with this, which was your original point.
        mynameisvlad 4y ago
        Their original point does not talk about American regulations at all, but rather that European regulations are stricter and therefore European cars will have tighter security. You're the one that chose to interpret that as "stricter than American".
      - olabyne 4y ago
        > In this case, the real weakness was that the immobilizer protocol allowed the car to start without message authentication, the CAN-related message injection thing was a sideshow. Right ? Because the messages are not authentified, once the car stolen, the thieves can even remove the immobilizer and put a DIY with a set of keys when they send the car in a container, to make it 'ready to ride' ouf-the-box
Gordonjcp 4y ago
Even in the mid-1990s the key-to-BECM protocols used in old Range Rovers was frankly massively overengineered, with a 48-bit rolling code key based off the vehicle's VIN and a 24-bit key code. The actual encryption routine is just a bunch of shifts, adds, and XORs, but so far it has resisted any attempt at spoofing keys. There's a somewhat simple trick to get the engine to start without the immobiliser (but it requires special tools), but if the body ECU is immobilised most of the vehicle electrics will be locked out too.
solarkraft 4y ago
You mean on the CAN bus? Then why doesn't the article mention it?
aaronbeekay 4y ago
I work in the space and I have not been impressed by the quality of Thatcham’s requirements once you get past the physical domain (door handle pull force, steering column locks, etc).

by bri3d 4y ago

droopyEyelids 4y ago

What do you think about how the article listed devices being available for all the European manufacturers?

bri3d 4y ago
I would love to see a story about one! I don't work in automotive RE, it's only a hobby, so I don't have budget to go find and buy "emergency start" tools like these security vendors do. As far as I am aware: there are All Keys Lost (AKL) immobilizer bypasses for, for example, Volkswagen Immo 5, but not "Emergency Start" bypasses. The difference is the level of access required: AKL bypasses require involved, long term physical access to a car, for example at a shop. They're useful for independent or fly-by-night shops and in a post-theft scenario, but they're not going to boost a car out of a driveway. Meanwhile, Emergency Start bypasses are plain-and-simple theft tools like the fake Bluetooth speaker from the article. All of the VW Immo 5 exploits which I am aware are of the AKL style and revolve around being able to extract cryptographic material (CS/MAC/ImoDat_noKeyMst/ImoDat_noKeySecu depending on who you ask what it's called) from a control module by physically removing it from the vehicle. This is a far cry from tapping the CAN bus at a headlight and injecting an unauthenticated CAN message.
- avree 4y ago
  What? This is a CAN bus hack, which is a standard that has been in EU cars for longer than US cars. I've worked with KeylessRide and also built my own hardware immobilizer/CANBUS device at a previous startup, and there is zero difference between European cars and American cars for this... By design, all nodes on a CAN network receive all frames, which is the root of the problem. There are some differences in ECU validation, plus whether or not the vehicle supports UDS diagnostics, but these are differences by manufacturer and have nothing to do with the continent the car is being used on.
  - bri3d 4y ago
    Calling something a "CAN bus hack" is like calling something an "Ethernet hack." It's just a bus, it's what's on the bus that matters. European, American, and Japanese cars have completely different immobilizer module cryptography implementations. In this case, the real weakness was that the immobilizer protocol allowed the car to start without message authentication, the CAN-related message injection thing was a sideshow. Generally, European cars have stronger immobilizer implementations. For example, in VW Immo 5, immobilizer messages are encrypted and authenticated using AES with a PRNG-based MAC. At a high level, participating modules need knowledge of a secret AES key in order to encrypt random number seed material. It's symmetric so it's still not perfect, but this type of simple "send one message through a headlight" attack would not be possible on these cars. Update: ah, I see you edited your comment. Yes, it has nothing to do with where the cars are _used_. My point was that European _manufacturers_ tend to have more secure immobilizer implementations, and I will stand by that point.
    - avree 4y ago
      You know that Toyota, the manufacturer here, is a Japanese company, right? European versus American regulations have literally nothing to do with this, which was your original point.
      - mynameisvlad 4y ago
        Their original point does not talk about American regulations at all, but rather that European regulations are stricter and therefore European cars will have tighter security. You're the one that chose to interpret that as "stricter than American".
    - olabyne 4y ago
      > In this case, the real weakness was that the immobilizer protocol allowed the car to start without message authentication, the CAN-related message injection thing was a sideshow. Right ? Because the messages are not authentified, once the car stolen, the thieves can even remove the immobilizer and put a DIY with a set of keys when they send the car in a container, to make it 'ready to ride' ouf-the-box

Gordonjcp 4y ago

Even in the mid-1990s the key-to-BECM protocols used in old Range Rovers was frankly massively overengineered, with a 48-bit rolling code key based off the vehicle's VIN and a 24-bit key code. The actual encryption routine is just a bunch of shifts, adds, and XORs, but so far it has resisted any attempt at spoofing keys. There's a somewhat simple trick to get the engine to start without the immobiliser (but it requires special tools), but if the body ECU is immobilised most of the vehicle electrics will be locked out too.

solarkraft 4y ago

You mean on the CAN bus? Then why doesn't the article mention it?

aaronbeekay 4y ago

I work in the space and I have not been impressed by the quality of Thatcham’s requirements once you get past the physical domain (door handle pull force, steering column locks, etc).