I am new to this and have some queries that I cant get my head around. I intend to get a free SSL cert from letsencrypt to install on my Checkpoint Firewall, so far I think I need to do the following
A) Generate Private Key (this can be done by yourself or your appliance)
B) From Private Key generate a CSR
C) Submit CSR to CA and pass challenge (this is what clients such as gethttpsforfree do)
D) Install Certificate on your appliance
There are two separate keypairs involved here: a public/private keypair for your Let’s Encrypt account (this is used instead of an account password), and a public/private keypair to identify your server to people who connect to it (here, this public key is mentioned in the CSR, and is going to be the subject key described in your certificate after the certificate is issued). The public key that Step 1 on that site asks for is a public key for your Let’s Encrypt account and is not related to the CSR at all. There’s a link there called “how do I generate this?” to explain how to generate a keypair if you’re not familiar with that process.
Later steps on that site will involve the CSR directly, but Step 1 doesn’t.