In case you need an easy way to generate SSL certificates for localhost, mkcert is the way to go.

mkcert is a simple tool for making locally-trusted development certificates. It requires no configuration.

$ mkcert -install
Created a new local CA 💥
The local CA is now installed in the system trust store! ⚡️
The local CA is now installed in the Firefox trust store (requires browser restart)! 🦊
 
$ mkcert example.com "*.example.com" example.test localhost 127.0.0.1 ::1
 
Created a new certificate valid for the following names 📜
 - "example.com"
 - "*.example.com"
 - "example.test"
 - "localhost"
 - "127.0.0.1"
 - "::1"
 
The certificate is at "./example.com+5.pem" and the key at "./example.com+5-key.pem" ✅

Thanks Filippo Valsorda for this great utility.