Full Disk Encryption - Revision history

Arch is the best: Move unlock KWallet with LUKS password section to KDE page

2026-04-21T01:04:26Z

Move unlock KWallet with LUKS password section to KDE page

← Older revision		Revision as of 01:04, 21 April 2026
Line 277:		Line 277:

	Again, the secondary drive will be unlocked and made available under <code>/dev/mapper/cryptstorage</code> for mounting.		Again, the secondary drive will be unlocked and made available under <code>/dev/mapper/cryptstorage</code> for mounting.

	~~= Autologin using LUKS password =~~

	One downside of full disk encryption is that you need to type in your password twice, once for unlocking the disk and once to log into your desktop. One approach is to skip the LUKS password, such as by using a TPM2, but is [https://oddlama.org/blog/bypassing-disk-encryption-with-tpm2-unlock/ difficult to properly secure]. The other approach is to enable autologin for your display manager:
	~~<syntaxhighlight lang="nix">~~
	{
	~~services.displayManager.autoLogin.user = "my username";~~
	}
	~~</syntaxhighlight>~~

	However, this breaks software such as KWallet which uses the login password to automatically unlock its keyring. The solution is to set the LUKS password, login password, and KWallet keyring password all to the same string, and then use the LUKS password to unlock KWallet. The LUKS password is first collected by a systemd initrd, saved to the kernel keyring, read out by SDDM via a PAM module, then finally passed off to KWallet.
	~~<syntaxhighlight lang="nix">~~
	{
	~~boot.initrd.systemd.enable = true;~~
	~~systemd.services.display-manager.serviceConfig.KeyringMode = "inherit";~~
	~~security.pam.services.sddm-autologin.text = pkgs.lib.mkBefore ''~~
	~~auth optional ${pkgs.systemd}/lib/security/pam_systemd_loadkey.so~~
	~~auth include sddm~~
	~~'';~~
	}
	~~</syntaxhighlight>~~

	= Further reading =		= Further reading =

Pigeon: fix consistency with wording "USB stick" and minor typos

2025-09-10T13:12:08Z

fix consistency with wording "USB stick" and minor typos

← Older revision		Revision as of 13:12, 10 September 2025
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	== Unattended Boot via USB ==		== Unattended Boot via USB ==

	Sometimes it is necessary to boot a system without needing an keyboard and monitor. You will create a secret key, add it to a key slot and put it onto an USB stick.		Sometimes it is necessary to boot a system without needing a keyboard and monitor. You will create a secret key, add it to a key slot and put it onto a USB stick.

	<syntaxhighlight lang="bash">		<syntaxhighlight lang="bash">
Line 55:		Line 55:
	=== Option 1: Write key onto the start of the stick ===		=== Option 1: Write key onto the start of the stick ===

	This will make the ~~usb-~~stick unusable for any other operations than being used for decryption. Write the key onto the stick:		This will make the USB stick unusable for any other operations than being used for decryption. Write the key onto the stick:

	<syntaxhighlight lang="bash">		<syntaxhighlight lang="bash">
Line 82:		Line 82:
	}</syntaxhighlight>		}</syntaxhighlight>

	=== Option 2: Copy Key as file onto a vfat ~~usb~~ stick ===		=== Option 2: Copy Key as file onto a vfat USB stick ===

	If you want to use your stick for other stuff or it already has other keys on it you can use the following method by Tzanko Matev. Add this to your <code>configuration.nix</code>:		If you want to use your stick for other stuff or it already has other keys on it you can use the following method by Tzanko Matev. Add this to your <code>configuration.nix</code>:
Line 100:		Line 100:
	boot.initrd.postDeviceCommands = pkgs.lib.mkBefore ''		boot.initrd.postDeviceCommands = pkgs.lib.mkBefore ''
	mkdir -m 0755 -p /key		mkdir -m 0755 -p /key
	sleep 2 # To make sure the ~~usb~~ key has been loaded		sleep 2 # To make sure the USB key has been loaded
	mount -n -t vfat -o ro `findfs UUID=${PRIMARYUSBID}` /key \|\| mount -n -t vfat -o ro `findfs UUID=${BACKUPUSBID}` /key		mount -n -t vfat -o ro `findfs UUID=${PRIMARYUSBID}` /key \|\| mount -n -t vfat -o ro `findfs UUID=${BACKUPUSBID}` /key
	'';		'';

Arch is the best: Add section about SDDM autologin using LUKS password

2025-08-20T15:29:22Z

Add section about SDDM autologin using LUKS password

@@ Line 1: / Line 1: @@
-There are a few options for full disk encryption. The easiest way is to use the graphical installer and choose „encrypt“ while doing the installation.
+There are a few options for full disk encryption. The easiest way is to use the graphical installer and choose "encrypt" while doing the installation.
 = LVM on LUKS =
@@ Line 277: / Line 277: @@
 Again, the secondary drive will be unlocked and made available under <code>/dev/mapper/cryptstorage</code> for mounting.
 = Further reading =
@@ Line 287: / Line 308: @@
 * [[Remote disk unlocking|Using Tor and SSH to unlock your LUKS Disk over the internet]].
 * [[Bcachefs]], filesystem which supports native encryption
-* [https://discourse.nixos.org/t/full-disk-encryption-tpm2/29454/2 Automatically unlock encrypted disks using tpm2]
+* [https://discourse.nixos.org/t/full-disk-encryption-tpm2/29454/2 Automatically unlock encrypted disks using TPM2]
 [[Category:Desktop]]
 [[Category:Server]]

Artoria2e5: /* Store key on TPM2 or FIDO2 */ ~

2025-07-10T11:21:40Z

Store key on TPM2 or FIDO2: ~

← Older revision		Revision as of 11:21, 10 July 2025
Line 140:		Line 140:
	</syntaxhighlight>		</syntaxhighlight>

	== Store key on ~~TPM2~~ or ~~FIDO2~~ ==		== Store key on FIDO2 device or TPM ==
	Unattended boot can also happen with ~~TPM2~~ or ~~FIDO2~~. This cannot be performed in a fully declarative way because every such security device is unique; some manual running of <code>systemd-cryptenroll</code> is required.		Unattended boot can also happen with a FIDO2 device (e.g. Yubikey) or TPM. This cannot be performed in a fully declarative way because every such security device is unique; some manual running of <code>systemd-cryptenroll</code> is required.

	For FIDO2, directly read the [https://github.com/NixOS/nixpkgs/blob/7be68f763d94cdb4c809b7980647828e3274a511/nixos/doc/manual/configuration/luks-file-systems.section.md chapter in the official manual].		For FIDO2, directly read the [https://github.com/NixOS/nixpkgs/blob/7be68f763d94cdb4c809b7980647828e3274a511/nixos/doc/manual/configuration/luks-file-systems.section.md chapter in the official manual].

Artoria2e5: /* Store key on TPM2 or FIDO2 */ ~

2025-07-10T11:20:31Z

Store key on TPM2 or FIDO2: ~

← Older revision		Revision as of 11:20, 10 July 2025
Line 141:		Line 141:

	== Store key on TPM2 or FIDO2 ==		== Store key on TPM2 or FIDO2 ==
	Unattended boot can also happen with TPM2 or FIDO2. This cannot be performed in a fully declarative way because every such security device is unique; some manual running of {{code\|systemd-cryptenroll}} is required.		Unattended boot can also happen with TPM2 or FIDO2. This cannot be performed in a fully declarative way because every such security device is unique; some manual running of <code>systemd-cryptenroll</code> is required.

	For FIDO2, directly read the [https://github.com/NixOS/nixpkgs/blob/7be68f763d94cdb4c809b7980647828e3274a511/nixos/doc/manual/configuration/luks-file-systems.section.md chapter in the official manual].		For FIDO2, directly read the [https://github.com/NixOS/nixpkgs/blob/7be68f763d94cdb4c809b7980647828e3274a511/nixos/doc/manual/configuration/luks-file-systems.section.md chapter in the official manual].

Artoria2e5 at 11:20, 10 July 2025

2025-07-10T11:20:14Z

← Older revision		Revision as of 11:20, 10 July 2025
Line 1:		Line 1:
	There are a few options for full disk encryption. The easiest way is to use the graphical installer and choose „encrypt“ while doing the installation.		There are a few options for full disk encryption. The easiest way is to use the graphical installer and choose „encrypt“ while doing the installation.

	= ~~Enter password on Boot (~~LVM on LUKS) =		= LVM on LUKS =

	In this example, everything except for the <code>/boot</code> partition is encrypted.		In this example, everything except for the <code>/boot</code> partition is encrypted.
Line 22:		Line 22:
	└─vg-root 254:2 0 225.3G 0 lvm /		└─vg-root 254:2 0 225.3G 0 lvm /
	</syntaxhighlight>		</syntaxhighlight>

			== Enter password on Boot ==

	The initrd needs to be configured to unlock the encrypted <code>/dev/sda2</code> partition during stage 1 of the boot process.		The initrd needs to be configured to unlock the encrypted <code>/dev/sda2</code> partition during stage 1 of the boot process.
Line 42:		Line 44:
	With <code lang="nix">initrd.luks.devices.cryptroot.device = "/dev/disk/by-uuid/UUID-OF-SDA2";</code>, the initrd knows it must unlock <code>/dev/sda2</code> before activating LVM and proceeding with the boot process.		With <code lang="nix">initrd.luks.devices.cryptroot.device = "/dev/disk/by-uuid/UUID-OF-SDA2";</code>, the initrd knows it must unlock <code>/dev/sda2</code> before activating LVM and proceeding with the boot process.

	= Unattended Boot via USB =		== Unattended Boot via USB ==

	Sometimes it is necessary to boot a system without needing an keyboard and monitor. You will create a secret key, add it to a key slot and put it onto an USB stick.		Sometimes it is necessary to boot a system without needing an keyboard and monitor. You will create a secret key, add it to a key slot and put it onto an USB stick.
Line 51:		Line 53:
	</syntaxhighlight>You can enable fallback to password (in case the USB stick is lost or corrupted) by setting the <code>boot.initrd.luks.devices.<name>.fallbackToPassword</code> option to <code>true</code>. By default, this option is <code>false</code> so you will have to perform a manual recovery if the USB stick becomes unavailable (which you may prefer, depending on your use case).		</syntaxhighlight>You can enable fallback to password (in case the USB stick is lost or corrupted) by setting the <code>boot.initrd.luks.devices.<name>.fallbackToPassword</code> option to <code>true</code>. By default, this option is <code>false</code> so you will have to perform a manual recovery if the USB stick becomes unavailable (which you may prefer, depending on your use case).

	== Option 1: Write key onto the start of the stick ==		=== Option 1: Write key onto the start of the stick ===

	This will make the usb-stick unusable for any other operations than being used for decryption. Write the key onto the stick:		This will make the usb-stick unusable for any other operations than being used for decryption. Write the key onto the stick:
Line 80:		Line 82:
	}</syntaxhighlight>		}</syntaxhighlight>

	== Option 2: Copy Key as file onto a vfat usb stick ==		=== Option 2: Copy Key as file onto a vfat usb stick ===

	If you want to use your stick for other stuff or it already has other keys on it you can use the following method by Tzanko Matev. Add this to your <code>configuration.nix</code>:		If you want to use your stick for other stuff or it already has other keys on it you can use the following method by Tzanko Matev. Add this to your <code>configuration.nix</code>:
Line 109:		Line 111:
	</syntaxhighlight>		</syntaxhighlight>

	= Unattended Boot via keyfile =		== Unattended Boot via keyfile ==

	A simpler but insecure option for unattended boots is to copy the keyfile into the initrd itself.		A simpler but insecure option for unattended boots is to copy the keyfile into the initrd itself.
Line 137:		Line 139:
	}		}
	</syntaxhighlight>		</syntaxhighlight>

			== Store key on TPM2 or FIDO2 ==
			Unattended boot can also happen with TPM2 or FIDO2. This cannot be performed in a fully declarative way because every such security device is unique; some manual running of {{code\|systemd-cryptenroll}} is required.

			For FIDO2, directly read the [https://github.com/NixOS/nixpkgs/blob/7be68f763d94cdb4c809b7980647828e3274a511/nixos/doc/manual/configuration/luks-file-systems.section.md chapter in the official manual].

			For TPM, replace the crypttab and systemd-cryptsetup option <code>fido2-device=auto</code> with <code>tpm-device=auto</code> for systemd stage 1. See [https://github.com/NixOS/nixpkgs/blob/7be68f763d94cdb4c809b7980647828e3274a511/nixos/tests/systemd-initrd-luks-tpm2.nix this integration test] in the nixpkgs source code repository.

			Because the TPM is attached to your computer, it provides no protection against a stolen computer when used on its own (it usually allows for setting a password, but that is it). It can only protect against a stolen drive.

	= zimbatm's laptop recommendation =		= zimbatm's laptop recommendation =

Incog267: Added a link to use tpm2 with disk encryption

2025-04-25T09:55:33Z

Added a link to use tpm2 with disk encryption

← Older revision		Revision as of 09:55, 25 April 2025
Line 276:		Line 276:
	* [[Remote disk unlocking\|Using Tor and SSH to unlock your LUKS Disk over the internet]].		* [[Remote disk unlocking\|Using Tor and SSH to unlock your LUKS Disk over the internet]].
	* [[Bcachefs]], filesystem which supports native encryption		* [[Bcachefs]], filesystem which supports native encryption
			* [https://discourse.nixos.org/t/full-disk-encryption-tpm2/29454/2 Automatically unlock encrypted disks using tpm2]


	[[Category:Desktop]]		[[Category:Desktop]]
	[[Category:Server]]		[[Category:Server]]

SigmaSquadron: Undo revision 18261 and 18262 by Juangiordana (talk) Reason: All files managed by Nix, including those in environment.etc, will always be world-readable in the /nix/store. This is fine, as /etc/crypttab does not contain secrets. Let us avoid no-ops in code examples.

2024-10-31T21:39:51Z

Undo revision 18261 and 18262 by Juangiordana (talk) Reason: All files managed by Nix, including those in environment.etc, will always be world-readable in the /nix/store. This is fine, as /etc/crypttab does not contain secrets. Let us avoid no-ops in code examples.

← Older revision		Revision as of 21:39, 31 October 2024
Line 257:		Line 257:
	<syntaxhighlight lang="nix">		<syntaxhighlight lang="nix">
	{		{
	environment.etc.crypttab ~~= {~~		environment.etc.crypttab.text = ''
	~~mode = "0600";~~		cryptstorage UUID=UUID-OF-SDB /root/mykeyfile.key
	text = ''		'';
	~~# <volume-name> <encrypted-device> [key-file] [options]~~
	cryptstorage UUID=UUID-OF-SDB /root/mykeyfile.key
	'';
	};
	}		}
	</syntaxhighlight>		</syntaxhighlight>

Juangiordana at 14:27, 31 October 2024

2024-10-31T14:27:23Z

← Older revision		Revision as of 14:27, 31 October 2024
Line 260:		Line 260:
	mode = "0600";		mode = "0600";
	text = ''		text = ''
	# <volume-name> <encrypted-device> <key-file> [options]		# <volume-name> <encrypted-device> [key-file] [options]
	cryptstorage UUID=UUID-OF-SDB /root/mykeyfile.key		cryptstorage UUID=UUID-OF-SDB /root/mykeyfile.key
	'';		'';

Juangiordana: Added `mode = "0600";`, otherwise the content of the file is world readable.

2024-10-31T14:10:11Z

Added `mode = "0600";`, otherwise the content of the file is world readable.

← Older revision		Revision as of 14:10, 31 October 2024
Line 257:		Line 257:
	<syntaxhighlight lang="nix">		<syntaxhighlight lang="nix">
	{		{
	environment.etc.crypttab.text = ''		environment.etc.crypttab = {
	cryptstorage UUID=UUID-OF-SDB /root/mykeyfile.key		mode = "0600";
	''		text = ''
			# <volume-name> <encrypted-device> <key-file> [options]
			cryptstorage UUID=UUID-OF-SDB /root/mykeyfile.key
			'';
			};
	}		}
	</syntaxhighlight>		</syntaxhighlight>