"known in advance" public key authentication?

[Ivan Shmakov]

	For my application, I need to establish a secure communication
	between two peers, and as it seems, TLS is a perfect fit for
	that.

	A feature of this application is that the public keys of the
	peers are effectively “known in advance”, so, while self-signed
	(unsigned?) X.509 certificates (or some OpenPGP ones) could be
	employed, there's no practical benefit from CC/WoT verification.

	Hence, the question is: is there a way to specify the local key
	pair and the remote public key to GnuTLS “directly”, just prior
	to connecting the remote?

	TIA.

-- 
FSF associate member #7257