What:		/sys/kernel/debug/turris-mox-rwtm/do_sign
Date:		Jun 2020
KernelVersion:	5.8
Contact:	Marek Behún <marek.behun@nic.cz>
Description:	(W) Message to sign with the ECDSA private key stored in
		    device's OTP. The message must be exactly 64 bytes (since
		    this is intended for SHA-512 hashes).
		(R) The resulting signature, 136 bytes. This contains the R and
		    S values of the ECDSA signature, both in big-endian format.