wireguard-initramfs

Use dropbear over wireguard.

Enables wireguard networking during kernel boot, before encrypted partitions are mounted. Combined with dropbear this can enable FULLY ENCRYPTED remote booting without storing key material or exposing ports on the remote network. An Internet connection simply needs to exist that can reach the wireguard server endpoint.

Normal dropbear connections and DNS resolution can be used to find wireguard endpoints. This essentially enables the creation of a fully encrypted remote-managed node, with the ability to prevent all local access.

Requirements

Working knowledge of Linux. Understanding of networking and Wireguard.

1. Debian Bullseye/Bookworm (any version with wireguard support should work, but untested).
2. Wireguard installed, configured and in a "known working" state.

Getting started

Installation is supported via make. Download, extract and configure contents, and install on target machine.

Download

Grab the latest release, untarball.

RELEASE=$(curl -Ls -o /dev/null -w %{url_effective} https://github.com/r-pufky/wireguard-initramfs/releases/latest | tr "/" "\n" | tail -n 1)
wget https://github.com/r-pufky/wireguard-initramfs/archive/refs/tags/"${RELEASE}".tar.gz
tar xvf "${RELEASE}".tar.gz
cd wireguard-initramfs-"${RELEASE}"

Configure

configs/initramfs file contains variables based on your working wireguard connection. Refer to wg set man page for additional information.

Installation

make install

⚠️

Most installs do not currently encrypt /boot; and therefore the client private key should be considered untrusted/compromised. It is highly recommended that a separate point-to-point wireguard network with proper port blocking is used for remote unlocking.

Rebuild initramfs to use using any of these methods:

make build_initramfs  # Debian
make build_initramfs_rpi  # Raspberry Pi
update-initramfs -u -k all && update-grub  # Manual build
reboot

Any static errors will abort the build. Mis-configurations will not be caught. Be sure to test while you still have physical access to the machine.

Dropbear

wireguard-initramfs can be combined with dropbear to enable remote system unlocking without needing control over the remote network, or knowing what the public IP of that system is. It also creates an encrypted no-trust tunnel before SSH connections are attempted.

Requirements

1. Dropbear installed, configured and in a "known working" state.

Configure

Set dropbear to use all network interfaces to ensure remote unlocks work over wireguard first. Then restrict to the wireguard network once it is working:

/etc/dropbear/initramfs/config

DROPBEAR_OPTIONS='... -p 172.31.255.10:22 ...'

Legacy compatibility (Migration)

If you are a user using a previous release, such as the one dated 2023-10-21, you can update your current projects by running:

sudo bash scripts/migrate_project_structure.sh
make install
make build_initramfs

Adapter configuration is located in /etc/wireguard/initramfs.conf and initramfs configuration is located in /etc/wireguard/initramfs.

This should keep your project structure and contents intact; however manual validation is required as full wireguard adapter configs are now supported.

Bug / Patches / Contributions?

All are welcome, please submit a pull request or open a bug!

Know debian packaging? Create a .deb package for this!