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This is not hard. App login sets up a session with VW (which is surely already does), except the session needs a database entry and not just a JWT-like token.

by amluto 2y ago

This is not hard. App login sets up a session with VW (which is surely already does), except the session needs a database entry and not just a JWT-like token. (Many auth frameworks do this anyway.) The database row needs to add a public key, and the server needs to send all the key changes to the car. And that’s about it.

magicalhippo 2y ago
Again, that's the easy part. The hard part is making it work reliably in the real world.
- deleted 2y ago
  [deleted]
- amluto 2y ago
  What, exactly, makes it hard to get this to work reliably in the real world? The app already won’t work without a valid login session. The car is already sending a little blob of data to the mothership containing a location. If the communication to the mothership changes to having the mothership send a list of keys and the car encrypt its blob, that’s basically it. The total increase in communication needed is one round trip to revalidate keys. I realize that modern development has layers and layers of documents and teams and overcomplicated interfaces, but this is the kind of thing that could be done by one developer, using two servers and a load balancer (or a more creative HA scheme with client assistance that can easily survive complete loss of a datacenter or two), that can handle the entire fleet.
  - magicalhippo 2y ago
    The app and car will have intermittent connection to the internet. My car for example doesn't have reliable connection when it's parked in the garage, which is where I charge it. Your solution would add a lot of extra edge cases that needs to be considered. You have to ensure the updated key is reliably transferred to the mothership in a timely fashion, and subsequently that the key is reliably transferred to the car in a timely fashion. That's the back-end stuff. There's also the front-end stuff, like will my SO understand why her app isn't showing the car's location but mine is? Not saying it's impossible, but it adds a lot of complexity beyond simply encrypting the location with multiple keys.
    - Dylan16807 2y ago
      If the car has enough signal to report, it has enough signal to get the key update. I don't see the problem. Losing connection for extended periods of time can get in the way of "timely" key updates but they won't cause the encryption to fail. > That's the back-end stuff. There's also the front-end stuff, like will my SO understand why her app isn't showing the car's location but mine is? Well the reasons I can think of are either things like the server being broken, which can happen without any encryption, or she didn't finish setting up her app and waiting for it to sync which can also happen without encryption. Or she was removed from the list because she didn't open the app for a year... which can also happen without encryption.
      - amluto 2y ago
        > Losing connection for extended periods of time can get in the way of "timely" key updates but they won't cause the encryption to fail. To be fair, if the car is offline while a newly installed app logs in, then the app won’t be able to locate the car until the car checks in. Which is not actually the end of the world, and there are ways to mitigate this. (See iMessage and Keybase for a couple of different approaches to this. See Signal for a shockingly poor group of bizarrely mutually incompatible solutions that barely work. I think that Matrix tries, too. MLS should be able to handle it, and piggybacking off an existing standard like MLS might be entirely reasonable albeit dramatically more complex than the simple solution I outlined.)
    - amluto 2y ago
      What edge cases? The app already can’t locate the car if the car hasn’t checked in recently enough.
  - mulmen 2y ago
    > I realize that modern development has layers and layers of documents Where do you work and are you hiring?
    - deleted 2y ago
      [deleted]

by amluto 2y ago

magicalhippo 2y ago

Again, that's the easy part. The hard part is making it work reliably in the real world.

deleted 2y ago
[deleted]
amluto 2y ago
What, exactly, makes it hard to get this to work reliably in the real world? The app already won’t work without a valid login session. The car is already sending a little blob of data to the mothership containing a location. If the communication to the mothership changes to having the mothership send a list of keys and the car encrypt its blob, that’s basically it. The total increase in communication needed is one round trip to revalidate keys. I realize that modern development has layers and layers of documents and teams and overcomplicated interfaces, but this is the kind of thing that could be done by one developer, using two servers and a load balancer (or a more creative HA scheme with client assistance that can easily survive complete loss of a datacenter or two), that can handle the entire fleet.
- magicalhippo 2y ago
  The app and car will have intermittent connection to the internet. My car for example doesn't have reliable connection when it's parked in the garage, which is where I charge it. Your solution would add a lot of extra edge cases that needs to be considered. You have to ensure the updated key is reliably transferred to the mothership in a timely fashion, and subsequently that the key is reliably transferred to the car in a timely fashion. That's the back-end stuff. There's also the front-end stuff, like will my SO understand why her app isn't showing the car's location but mine is? Not saying it's impossible, but it adds a lot of complexity beyond simply encrypting the location with multiple keys.
  - Dylan16807 2y ago
    If the car has enough signal to report, it has enough signal to get the key update. I don't see the problem. Losing connection for extended periods of time can get in the way of "timely" key updates but they won't cause the encryption to fail. > That's the back-end stuff. There's also the front-end stuff, like will my SO understand why her app isn't showing the car's location but mine is? Well the reasons I can think of are either things like the server being broken, which can happen without any encryption, or she didn't finish setting up her app and waiting for it to sync which can also happen without encryption. Or she was removed from the list because she didn't open the app for a year... which can also happen without encryption.
    - amluto 2y ago
      > Losing connection for extended periods of time can get in the way of "timely" key updates but they won't cause the encryption to fail. To be fair, if the car is offline while a newly installed app logs in, then the app won’t be able to locate the car until the car checks in. Which is not actually the end of the world, and there are ways to mitigate this. (See iMessage and Keybase for a couple of different approaches to this. See Signal for a shockingly poor group of bizarrely mutually incompatible solutions that barely work. I think that Matrix tries, too. MLS should be able to handle it, and piggybacking off an existing standard like MLS might be entirely reasonable albeit dramatically more complex than the simple solution I outlined.)
  - amluto 2y ago
    What edge cases? The app already can’t locate the car if the car hasn’t checked in recently enough.
- mulmen 2y ago
  > I realize that modern development has layers and layers of documents Where do you work and are you hiring?
  - deleted 2y ago
    [deleted]