Posts

What is GPG

Paraphrasing from the Arch Wiki, GPG is basically an implementation of PGP (Pretty Good Privacy)/ RFC 4880. You can use it to sign stuff, encrypt stuff, and authenticate yourself (eg over SSH or S/MIME).

Using GPG for SSH

1. Generate Master Key

   • This is the key you’ll use to create subkeys. As such you’ll want to keep this safe somewhere

   • 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

     $ gpg --full-generate-key --expert gpg (GnuPG) 2.4.3; Copyright (C) 2023 g10 Code GmbH This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Please select what kind of key you want: (1) RSA and RSA (2) DSA and Elgamal (3) DSA (sign only) (4) RSA (sign only) (7) DSA (set your own capabilities) (8) RSA (set your own capabilities) (9) ECC (sign and encrypt) *default* (10) ECC (sign only) (11) ECC (set your own capabilities) (13) Existing key (14) Existing key from card Your selection? 11

     • We want to pick ECC, since that’s the more secure algorithm of these

   • Next, we want to disable signing, since we’ll only use this key to make more keys (i.e. we’ll be certifying other keys)

• Okay so you’ve got a server now and need a reverse proxy
• Traefik is pretty decent at that, it’ll set up your HTTPS certs and auto generate routes from your docker images
• only problem is its an absolute bitch to set up
• Here’s a stripped down docker-compose.yml to give you an idea of how I have it set up
• The end result should be a lighttpd server running on blog.argentumcation.com

import { Accordion, AccordionItem } from “accessible-astro-components”;

Here’s how to create a resident SSH Key using a security key

1

ssh-keygen -t ed25519-sk -Oresident

If that one doesn’t work,

1

ssh-keygen -t ed25519-sk -Oresident -Oapplication=ssh:key