So I’m making a program in combination with a microcontroller. The program is for uploading files to the SD card of which the microcontroller reads from. Some of the files have to contain passwords. So they have to be generated on the desktop application then sent to the microcontrollers SD card.
The problem is that the microcontroller I use is rather small, powerless, already runs a lot of code and interfaces with other modules. The thing is, I’m stuck on this mc and can’t change it for several reasons.
What is the absolute safest way to store the passwords in this case.
Technical details:
Microcontroller: ATmega32u4
Left flash: ~1kB - 200B
Left memory: 900 - 400 B
Although I’m re-writing all the code to not use c++ style strings and general optimizing.
Even though the estimates I have given are not accurste because I’m re-writing everything. What is the best way to implement safe storage of passwords.
Note:
Everything is stored on a SD card so all files can be copied to a computer where all types of attacks can be made.