Use Ledger For ECDSA Signature in Python Substrate Interface

Question

I'm trying to create a KeyPair class instance (https://github.com/polkascan/py-substrate-interface/blob/master/substrateinterface/base.py) from a Ledger hardware wallet. Does anyone know how to do this (if it's even possible)?

Alternatively, I can just generate the signature payload and use other tooling to sign it with the Ledger. But eventually it would be nice to be able to use Ledger out of the box to sign transactions in substrate interface. I can submit a PR with this functionality if it doesn't already exist.

Answer 1

Making a PR will certainly help others in the same position, we were actually discussing it this week. It seems like it would be possible since you only need to pass the payload to the Ledger to get it signed. The payload generation is already in the Python interface.

The harder bits would be to communicate with the Ledger itself. (Although this should be standard, so if done somewhere in the wiser blockchain space already, it should be adaptable)