Change API of init_key_ctx to use struct key_parameters

Change API of init_key_ctx to use struct key_parameters

This introduces a new structure key_parameters. The reason is that the
current struct serves both as an internal struct as well as an
on-wire/in-file format. Separate these two different usages to allow
extending the struct.

Change-Id: I4a981c5a70717e2276d89bf83a06c7fdbe6712d7
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Frank Lichtenheld <frank@lichtenheld.com>
Message-Id: <20241227111133.5893-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg30228.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>