I'd love to get away from some of openssl's arcane flags... :-)
/usr/bin/ssh -V
OpenSSH_6.9p1, LibreSSL 2.1.7 $ openssl version
OpenSSL 0.9.8zg 14 July 2015
$ which openssl
/usr/bin/opensslDon't forget their version is ancient (API-wise; they back-port fixes) and LibreSSL is much newer, so it's not a drop in replacement for such an old version.
Lo, how times have changed. ;-)
Apple thus stopped shipping OpenSSL and has officially deprecated it, these days you won't find headers for it anywhere in the stock system and there is no official way to link against it anymore either in El Capitan. It just exists for backwards compatibility.
If a developer now wants to use OpenSSL in their binary instead of the Common Crypto framework that Apple provides they will have to provide their own version of the library in their application, and they are then responsible for making sure users get patched in time.
These two links roughly explain the issues/reasoning:
http://rentzsch.tumblr.com/post/33696323211/wherein-i-write-... http://ludovicrousseau.blogspot.com/2011/08/mac-os-x-lion-an...