lib: add support for keyed-hashing with MD5

  * lib/md5.[ch] Add implementation of HMAC-MD5 from RFC 2104.

From: Josh Bailey <joshb@google.com>
Signed-off-by: Avneesh Sachdev <avneesh@opensourcerouting.org>
Signed-off-by: David Lamparter <equinox@diac24.net>
2 files changed