Create Root CA (Done once)
Create Root Key
Attention: this is the key used to sign the certificate requests, anyone holding this can sign certificates on your behalf. So keep it in a safe place!
openssl genrsa -des3 -out rootCA.key 4096
If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.