Our self-signed certificate was generated like this:
(192.168.0.119 is the IP address of the machine running the Hak5 Cloud C2 server)
openssl req -newkey rsa:2048 -x509 -sha256 -days 3650 -nodes -out cert.crt -keyout cert.key
Country Name (2 letter code) [AU]:GB
State or Province Name (full name) [Some-State]:Manchester
Locality Name (eg, city) []:Manchester
Organization Name (eg, company) [Internet Widgits Pty Ltd]:Hak5
Organizational Unit Name (eg, section) []:Developers
Common Name (e.g. server FQDN or YOUR name) []:192.168.0.119