OpenSSL: don't use direct access to the internal of RSA

OpenSSL: don't use direct access to the internal of RSA

OpenSSL 1.1 does not allow us to directly access the internal of
any data type, including RSA. We have to use the defined
functions to do so.

Compatibility with OpenSSL 1.0 is kept by defining the corresponding
functions when they are not found in the library.

Signed-off-by: Emmanuel Deloget <logout@free.fr>
Acked-by: Steffan Karger <steffan.karger@fox-it.com>
Message-Id: <20170612134330.20971-4-logout@free.fr>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg14790.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>