It would be better if we created the required test files as part of the test run. (Why not? Too slow?) Alternatively, I have been thinking that maybe we could make the output more reproducible by messing with whatever random seed OpenSSL uses. Or maybe use a Python library to create the files. Some things to think about.
I think this last idea is the way to go. I've hand-crafted GIF images and PGP messages in the past; surely we have enough combined brain power around here to craft our own SSL files? It may even be a wheel that someone has invented already.