Arch Linux

6i5

Member

Registered: 2024-06-09

Posts: 14

Does GRUB not support unlocking LUKS2-encrypted boot partitions?

In my previous posts I was able to encrypt my entire disk except boot. I simplified my partitioning layout and tried again. This time, there is an EFI partition, the entire root directory which is unencrypted and the encrypted boot. I have confirmed from last time that my keyboard layout is not the issue. However GRUB is still unable to unlock cryptboot. Is this proof that GRUB's support for LUKS2 boot is still broken, or could I have missed a crucial step?

> lsblk -f
NAME				FSTYPE		FSVER	MOUNTPOINTS
loop0				squashfs	4.0		/run/archiso/airootfs
nvme0n1
├─nvme0n1p1			vfat		FAT32	/mnt/efi
├─nvme0n1p2			LVM2_member	LVM2 001
│ └─vg001-cryptboot	crypto_LUKS	2
│   └─boot			ext4		1.0		/mnt/boot
└─nvme0n1p3			ext4		1.0		/mnt/

> cat /mnt/etc/fstab
# <file system> 	<dir> 	<type> 	<options>
# /dev/nvme0n1p3
UUID=...			/		ext4	rw,realtime
# /dev/mapper/boot
UUID=...			/boot	ext4	rw,realtime
# /dev/nvme0n1p1
UUID=...			/efi	vfat	rw,realtime,...

> cat /etc/mkinitcpio.conf
...
HOOKS=(base udev autodetect microcode modconf kms keyboard keymap consolefont block lvm2 encrypt filesystems fsck)

> cat /etc/default/grub
...
GRUB_ENABLE_CRYPTODISK=y
...

> grub-install --target=x86_64-efi --efi-directory=/efi --bootloader-id=GRUB --recheck
Installing for x86_64-efi platform.
Installation finished. No error reported.
> grub-mkconfig -o /boot/grub/grub.cfg
...
done

cryptearth

Member

Registered: 2024-02-03

Posts: 2,033

Re: Does GRUB not support unlocking LUKS2-encrypted boot partitions?

https://wiki.archlinux.org/title/GRUB#Encrypted_/boot
limited support for luks2 - pbkdf only

6i5

Member

Registered: 2024-06-09

Posts: 14

Re: Does GRUB not support unlocking LUKS2-encrypted boot partitions?

https://wiki.archlinux.org/title/GRUB#Encrypted_/boot
limited support for luks2 - pbkdf only

> cryptsetup luksFormat --type luks2 --cipher aes-xts-plain64 --hash sha512 --iter-time 5000 --key-size 512 --pbkdf=pbkdf2 --use-urandom --verify-passphrase /dev/vg001/cryptboot

I used the command above to encrypt the boot partition. As you can see LUKS2 pbkdf2 was used, yet GRUB was unable to unlock it.

blueman

Member

From: web

Registered: 2021-02-25

Posts: 2

Re: Does GRUB not support unlocking LUKS2-encrypted boot partitions?

I think it was caused by "--hash sha512". With sha256 it works fine.

Scimmia

Fellow

Registered: 2012-09-01

Posts: 13,700

Re: Does GRUB not support unlocking LUKS2-encrypted boot partitions?

Or because grub has been updated since then. Everything in this thread is out of date, which is why you shouldn't bump old threads.

WorMzy

Administrator

From: Scotland

Registered: 2010-06-16

Posts: 13,417

Website

Re: Does GRUB not support unlocking LUKS2-encrypted boot partitions?

Mod note: closing, for reasons noted.

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