Remote Start

[overkillthemighty]

For quite some time I have wanted a good reliable way to remote start my truck, especially in the winter. I started looking at meshtastic as an option a few months ago and have a few nodes up in my community now. I have an EVO ALL remote start system installed already, but it relies on the OEM key fob, so it is only useful if I am in line of sight and within a hundred feet. In my research I found that meshtastic uses encryption, but is susceptible to replay attacks, which was a little disappointing at first, as I was going to connect a GPIO to the wire on the unit that will trigger a start, but then I remembered coming across a project called EvoLink for allowing an Arduino to talk to the EVO unit and it all clicked!

My plan is to use a 3.3v Arduino as a go-between to allow remote start as well as locking and unlocking. It should allow some lighting control as well as coolant temp readouts as well. I will be using a secure channel for communication that is set as default on the unit in the truck, and the serial module with text msg mode enabled. To address replay attacks, I am going to use a handshake model for the remote start and locks that goes like this:

Send a command to "wake" the Arduino up.
It replies with a list of commands and a randomly generated number that is valid for 60 seconds.
I send the command I want along with the number
It confirms the command was received.

In theory this should be relatively secure from what I understand of the system. I will post updates (I just got the Arduino doing the handshake over my channel, going to get it connected to the EVO and try sending the commands when I have time to get into the dash.)