Eli, Sorry if you misunderstood how I decrypted a LUKS2 / from a booted LUKS1 encrypted /boot Arch system.
No CLI, nor initramfs was involved. I merely booted my LUKS1 encrypted /boot, logged into SDDM, then used KDE's Dolphin to unlock another LUKS2 / partition. And, of course, grub can boot a non-encrypted /boot with an encrypted LUKS2 /. Following that LUKS2 boot, Dolphin can be used to unlock a LUKS1 /, but neither approach tests grub unlocking, as far as I know. ++++++++++++++++ Patrick, Thank you for your follow-up, and understood re: the ongoing development, and the likely v2.06 LUKS2 support miss. Also, noted on the additional modules you mentioned. As far as I can tell, the documentation concerning `grub-install --modules=xxx` is very sparse. If you know a decent resource, please link it. Cheers ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ On Friday, August 28, 2020 4:51 PM, Patrick Steinhardt <p...@pks.im> wrote: > On Fri, Aug 28, 2020 at 11:37:24AM -0400, Eli Schwartz wrote: > > > On 8/28/20 11:28 AM, HardenedArray via Grub-devel wrote: > > > > > I run Arch Linux as an encrypted /, /boot and swap system. That > > > encrypted /boot is nothing more than a folder under /, however two > > > Keyslots are required to boot. > > > If I understand the boot process correctly, LUKS Keyslot 1 is used by > > > grub to unlock /boot, then control is handed off to the kernel which > > > uses Keyslot 0 to unlock /. My passphrase, entered once, unlocks > > > both. > > > Grub can easily unlock /boot, assuming / is originally encrypted as a > > > `type= luks1` partition. It seems, however, it is not possible for > > > grub to unlock this same /boot if / is converted to `--type= luks2`. > > > Is my assumption correct, and if so, what is preventing grub from > > > this `type= luks2` /boot unlocking? > > > I am running: grub-git 2.04.rc1.r19.g4e7b5bb3b-1 from the Arch (AUR). > > > This package was last updated on 7 Feb 2020. See: > > > https://aur.archlinux.org/packages/grub-git/ > > > I originally encrypted the partition with: `cryptsetup -c aes-xts-plain64 > > > -h sha512 -s 512 --use-random --type luks1 luksFormat /dev/sdXZ` > > > Then I set up two LVs: swap (512M) and / (remaining partition space). > > > That swap LV is assigned as `dm-1` and / is assigned as `dm-2`. dm-2 > > > runs BTRFS, if that matters. Grub boots that system without issue. > > > The process I used to test LUKS2 encrypted /boot support: > > > > > > 1. UEFI boot from any reasonably recent arch iso, and run: > > > `cryptsetup convert --type luks2 /dev/sdXZ`. That command will > > > succeed, and luksDump will show PBKDF: pbkdf2 for both Keyslot 0 and > > > > > > 2. > > > 3. Run cryptsetup open /dev/sdXY <something> > > > > > > 4. Mount everything and arch-chroot into / > > > > > > 5. Run `mkinitcpio -P linux` > > > > > > 6. Run `grub-install --target=x86_64-efi --efi-directory=/efi > > > --modules="luks2 part_gpt cryptodisk" --bootloader-id=<some-id>`. > > > > > > > > > Note: If `--modules="luks2 part_gpt cryptodisk"` is not appended to > > > grub-install, then the `ls` results in step 9 (below) only lists > > > (proc) and (hd0) - and/or cryptodisk: command not found. > > > > > > 6. Run grub-mkconfig -o /boot/grub/grub.cfg > > > > > > 7. Exit, umount and reboot. > > > > > > 8. Immediately following power on: you are greeted by the dreaded: > > > error: disk 'lvmid/some-lengthy-UUID' not found. Entering rescue > > > mode. That lengthy UUID is exact UUID of my `dm-2` which is my > > > encrypted / LV. > > > > > > 9. At the `grub rescue>` prompt: type `ls`. There I see (proc) (hd0) > > > and (hd0,gpt1)...(hd0,gpt7) where gpt7 is my last partition and where > > > my encrypted / resides. > > > > > > 10. Still at `grub rescue>` type: `cryptomount (hd0,gpt7)` which then > > > requires my passphrase. After correct passphrase entry, and hitting > > > Enter only returns: > > > > > > > > > `error: Could not parse digest 1.` > > > Incredibly, if you repeat step 10 and intentionally enter an > > > incorrect passphrase, you get the same: > > > `error: Could not parse digest 1.` > > > In fact, if you enter NO passphrase and hit Enter, you also get: > > > `error: Could not parse digest 1.` > > > Very frustrating indeed! > > > Does anyone know why grub is failing this way, and does a workaround > > > exist? > > > Thank you for your time...suggestions welcome. > > > > If I remember correctly, you mentioned on IRC that you could > > successfully use grub-git to cryptomount a luks1 /boot/grub directory, > > then use the grub modules there to further cryptomount a luks2 partition. > > The problem sounded like an issue actually getting grub-install to > > generate a grubx64.efi with proper, usable luks2 support. > > Am I right? > > If that's the case, then this is entirely expected right now. > grub-install doesn't yet include the required modules automatically for > LUKS2 support. There is ongoing work to enable this, first by > recognizing LUKS2 devices at all [1,2]. But we're not there yet, and > it's unlikely to happen for release 2.06. > > Until then, you'll have to manually add required GRUB modules for LUKS2, > PBKDF2 and the gcry modules required for your configured cipher/hash > combination. > > Patrick > > [1]: https://lists.gnu.org/archive/html/grub-devel/2020-05/msg00235.html > [2]: https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00050.html > > Grub-devel mailing list > Grub-devel@gnu.org > https://lists.gnu.org/mailman/listinfo/grub-devel _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel