Add support for loading RSA private key files from PKCS #11 tokens,
identified by PKCS #11 URIs. Add a new 'pkcs11_libs' UAT which can
dynamically load PKCS #11 provider libraries that are not found by
p11-kit.
The configuration GUI will need additional code to discover available
PKCS #11 tokens and will be added later.
This feature requires GnuTLS 3.4 with PKCS #11 support, so Windows,
macOS via Homebrew, Ubuntu 16.04, Debian Stretch. Not supported: RHEL7.
Currently macOS via official packages disables PKCS #11 support, so that
will also not work.
Change-Id: I20646bfd69c6bd13c8c2d27cb65c164a4b0b7a66
Reviewed-on: https://code.wireshark.org/review/30855
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot
Reviewed-by: Peter Wu <peter@lekensteyn.nl>