Linux, Open Source & Unrelated Topics by Paul Barker

Rekeying

Published:
Tags: pgp, ssh, home-network

I've recently made a couple of changes to my development environment(s): I now have a shiny new Ryzen 7 7700 based development box (more details of this box to follow in future posts...) and a WSL instance on my work laptop (running Ubuntu 22.04 for maximum compatibility with my work needs). As I've been configuring these environments, I've taken the opportunity to extend the lifetimes of my PGP keys (as they were nearing expiry) and generate new SSH keys.

PGP key lifetimes extended

I created two PGP keys back in May & June 2021 - one for when I'm wearing my "personal" hat and one for when I'm wearing my "Principal Software Engineer @ SanCloud Ltd" hat. Each key was created with an initial lifetime of 2 years, which means the expiry dates have been approaching. As both keys are still in use I've extended their lifetimes, aligning both on a new expiry date of 2025-04-30. If you have these keys in your keyring, please refresh them to pick up the new expiry dates.

A bundle containing both PGP keys can be downloaded from this site. These keys are also available on keys.openpgp.org, see their usage guide for instructions on how to fetch keys from that service.

I'd like to highlight Linux Foundation's excellent document Protecting code integrity with PGP which I used as my reference back in 2021 when originally creating these keys and planning how they would be used. I referred to this document again this week to remind me how to extend the lifetime of existing keys. It's a comprehensive guide and set of best practices which I highly recommend reading.

New SSH keys

Each development environment has also been given a new SSH keypair. I try not to cycle through keypairs too often in order to avoid additional sysadmin work for both myself and those I work with, but a change once every few years is ok. If either system is rebuilt or reinstalled within the next couple of years, the appropriate keypair will be reused unless there's a strong reason to change it.

If you ever need to give me remote access to a machine, please add the following SSH public keys to the relevant authorized_keys file:

ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIH7G2D7d165H9rohNED/MmnW68Z01U0AFYghi8vgT3Pv pbarker@tau.cephei.uk
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPpzQXVeU/FgnPrN3KIayuvuAcFpymoovkHkGFTYz3bY pbarker@laptop.cephei.uk

These keys can also be downloaded as a simple text file and verified with a detached PGP signature.