I had soooo much fun with that when I found out that one of my clients was connecting to a Logjam-vulnerable server and the OpenSSL-based code connecting to it

I had soooo much fun with that when I found out that one of my clients was connecting to a Logjam-vulnerable server and the OpenSSL-based code connecting to it suddenly failed without explanation after a security patch. I found it by accident because I was able to reproduce with openssl s_server, which happened to be presenting a weak DH key by default as well.