LUKS-Encrypted File Systems
NixOS supports file systems that are encrypted using
LUKS (Linux Unified Key Setup). For example, here is how
you create an encrypted Ext4 file system on the device
/dev/disk/by-uuid/3f6b0024-3a44-4fde-a43a-767b872abe5d:
# cryptsetup luksFormat /dev/disk/by-uuid/3f6b0024-3a44-4fde-a43a-767b872abe5d
WARNING!
========
This will overwrite data on /dev/disk/by-uuid/3f6b0024-3a44-4fde-a43a-767b872abe5d irrevocably.
Are you sure? (Type uppercase yes): YES
Enter LUKS passphrase: ***
Verify passphrase: ***
# cryptsetup luksOpen /dev/disk/by-uuid/3f6b0024-3a44-4fde-a43a-767b872abe5dcrypted
Enter passphrase for /dev/disk/by-uuid/3f6b0024-3a44-4fde-a43a-767b872abe5d: ***
# mkfs.ext4 /dev/mapper/crypted
The LUKS volume should be automatically picked up by
nixos-generate-config, but you might want to verify that your
hardware-configuration.nix looks correct.
To manually ensure that the system is automatically mounted at boot time as
/, add the following to
configuration.nix:
boot.initrd.luks.devices.crypted.device = "/dev/disk/by-uuid/3f6b0024-3a44-4fde-a43a-767b872abe5d";
."/".device = "/dev/mapper/crypted";
Should grub be used as bootloader, and /boot is located
on an encrypted partition, it is necessary to add the following grub option:
= true;FIDO2
NixOS also supports unlocking your LUKS-Encrypted file system using a FIDO2 compatible token. In the following example, we will create a new FIDO2 credential
and add it as a new key to our existing device /dev/sda2:
# export FIDO2_LABEL="/dev/sda2 @ $HOSTNAME"
# fido2luks credential "$FIDO2_LABEL"
f1d00200108b9d6e849a8b388da457688e3dd653b4e53770012d8f28e5d3b269865038c346802f36f3da7278b13ad6a3bb6a1452e24ebeeaa24ba40eef559b1b287d2a2f80b7
# fido2luks -i add-key /dev/sda2f1d00200108b9d6e849a8b388da457688e3dd653b4e53770012d8f28e5d3b269865038c346802f36f3da7278b13ad6a3bb6a1452e24ebeeaa24ba40eef559b1b287d2a2f80b7
Password:
Password (again):
Old password:
Old password (again):
Added to key to device /dev/sda2, slot: 2
To ensure that this file system is decrypted using the FIDO2 compatible key, add the following to configuration.nix:
boot.initrd.luks.fido2Support = true;
boot.initrd.luks.devices."/dev/sda2".fido2.credential = "f1d00200108b9d6e849a8b388da457688e3dd653b4e53770012d8f28e5d3b269865038c346802f36f3da7278b13ad6a3bb6a1452e24ebeeaa24ba40eef559b1b287d2a2f80b7";
You can also use the FIDO2 passwordless setup, but for security reasons, you might want to enable it only when your device is PIN protected, such as Trezor.
boot.initrd.luks.devices."/dev/sda2".fido2.passwordLess = true;