It's https://en.wikipedia.org/wiki/Galois_Counter_Mode and IIRC it was added to ...

djmdjm on Nov 8, 2013 | parent | context | favorite | on: OpenSSH security advisory

It's https://en.wikipedia.org/wiki/Galois_Counter_Mode and IIRC it was added to OpenSSL in the 1.0.1 release.

Don't let my hazy recollection be a substitute for checking your platform though :) (see some good recipes in this thread)