What:		/sys/kernel/debug/turris-mox-rwtm/do_sign
Date:		Jun 2020
KernelVersion:	5.8
Contact:	Marek Behún <marek.behun@nic.cz>
Description:

		======= ===========================================================
		(Write) 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).
		(Read)  The resulting signature, 136 bytes. This contains the
			R and S values of the ECDSA signature, both in
			big-endian format.
		======= ===========================================================