> I have an application that runs on an old OS that currently has
OpenSSL 0.9.8a
So you should be able to compile and install the last 0.9.8 release, https://www.openssl.org/source/old/0.9.x/openssl-0.9.8zc.tar.gz Note that this is more than two years old. Many fixes have happened since then.
Good luck.