irc/quassel by default generates 1024 bit RSA keys which are a bit dated.
openssl req -x509 -nodes -days 365 -newkey rsa:1024 \
I changed it to 4096 bit on my server and it quassel functions correctly with it. I'd suggest changing it to 2048 at least, preferably 4096.
A commit references this bug:
Date: Tue Mar 24 09:47:52 UTC 2015
New revision: 382075
- Generate 4096 bit RSA certificate
Suggested by: Robert Sevat