I wish AES-GCM was available...but openssl can't do it on its own without further dependencies to parse the authentication correctly.
Really this whole layer is complelty redundant actually. It's already E2EE without openssl via Tor. I like that it's encrypted before I hit the network pipe though.
great attitude for approximately everything except, perhaps, cryptography.
especially since the initial encryption is mostly redundant, i would encourage that you, at some point, consider reducing the number of ciphers.
Then maybe your scientists should spend some time to stop and consider whether they should ;)
But seriously, I'd just limit this to one option on the selection side, even if you continue supporting more than that at the protocol level for cryptographic agility.
It still supports a bunch of outdated crap including (on my system) RC4, RC2(!) and DES (yes, the 56 bit key one, not just 3DES).
So in addition to a sensible default I guess it would also be a good idea to tag choices that you believe to be outdated with a large warning. That way you haven't rolled your own crypto, you haven't forced your views on others, but you have done your best to enable end users to operate your tool in a sensible manner.
Within the last 12 months, I had to write a script for a buddy at work that turned off availability of freaking freaking 56 bit DES in OpenSSH, which was available because was provided by openssl. I'm certain it was still there to provide compatibility for something(s) critical out there that depends on it, and while I can't imagine why anybody would choose to use it, it's there and it's awful.