Seeding nrfutil random number generator for generating keys

[Chris Ergo]

I haven't been able to find information on the method used by nrfutil to generate the private keys. How secure is the randomness without a seed? Can I seed it?

[Einar Thorsrud]

Hi,

You can see the implementation yourself in signing.py, which basically just use generate from the Python ecdsa module. You can read more how it handles entropy and how it can be modified (including seeded) in the documentation for that module. Also note that you are free to use any other tool to generate the key, and then just point to that .pem file for later use with nrfutil.