I’ve been trying to set up hibernation on my laptop while also maintaining an encrypted root partition and swap using secure boot and my laptop’s TPM. I’ve documented the steps I’ve followed below, but I still am unable to enable hibernation.

I was under the impression that the only reason you can’t normally have both an encrypted harddrive and hibernation was because swap had to be encrypted as well, but if both the root partition and the swap are encrypted, I’m using UEFI secure boot, and they are automatically decrypted at boot using the TPM, shouldn’t that relieve those security concerns?

After completing the below, entering systemctl hibernate errors saying hibernation is not set up for the system. Am I missing something or is it just not possible? I can confirm not needing to enter passwords for my swap or root FS due to the TPM unlock.

My personal documentation below:

Drop into root shell

sudo su -

Setup LUKS encryption with automatic unlock with TPM

Install necessary components, regenerate initramfs and reboot

dnf install -y clevis clevis-luks clevis-dracut clevis-udisks2 clevis-systemd
dracut -fv --regenerate-all && systemctl reboot

Identify swap and root partition devices, names, and luks UUIDs…

lsblk -f
cryptsetup luksUUID <UUID>

In my case, my home partition is on /dev/nvme0n1p4 and my swap is /dev/nvme0n1p3

# the encrypted home partition
clevis luks bind -d /dev/nvme0n1p4 tpm2 '{"pcr_ids":"1,4,5,7"}'

# the encrypted swap
clevis luks bind -d /dev/nvme0n1p3 tpm2 '{"pcr_ids":"1,4,5,7"}'

Set a timeout before the system asks for a password, to allow time for the TPM to load and enter the password for you systemctl edit systemd-ask-password-plymouth.service

Add the below then ctrl+o ctrl+x to save and exit

[Service]
ExecStartPre=/bin/sleep 10

Create a dracut configuration file to install the systemd-ask-password-plymouth service: vi /etc/dracut.conf.d/systemd-ask-password-plymouth.conf

Add the below, ensure there are spaces inside the quotation marks on either side of the filename

install_items+=" /etc/systemd/system/systemd-ask-password-plymouth.service.d/override.conf "

Regenerate initramfs and reboot

dracut -fv ‐‐regenerate-all && systemctl reboot

Edit crypttab file (/etc/crypttab)to specify decryption of swap file at boot, duplicate the already present line for your root FS crypttab entry and change the UUIDs to reflect the swap file, use cryptsetup luksUUID /dev/nvme0n1p3 and cryptsetup luksUUID /dev/nvme0n1p4 to get the luks UUIDs for your root and swap partitions.

<swap LUKS UUID> UUID=<swap UUID> none x-initrd.attach
<root FS LUKS UUID> UUID=<root FS UUID> none x-initrd.attach

Regenerate initramfs and reboot: dracut -fv --regenerate-all && systemct reboot

Edit fstab to include swap, append the following to /etc/fstab:

UUID=<swap UUID> none swap defaults,x-systemd.device-timeout=0 1 1

Rebind your home and swap partitions. You will have to do this every time you update the kernel.

# encrypted home partition
clevis luks regen -d /dev/nvme0n1... -s 1

# encrypted swap
clevis luks regen -d /dev/nvme0n1... -s 1
  • moonpiedumplings@programming.devEnglish
    2·
    15 hours ago

    I don’t have/use TPM, but I do have encrypted swap and hibernation on a fully encrypted drive.

    The trick is to put the kernels in the root partition, which is encrypted by LUKS. Then, you can also put a swapfile in that same partition.

    The only unencrypted part of my system is /boot/etfi, which is the EFI partition that holds nothing but the grub binary. Grub configs and kernels are in /boot, which is on the root partition, and encrypted in LUKS.

    Grub automatically scans hard drives, before prompting with a password to decrypt the root and everything on it. Because grub is doing the decryption, rather than the kernels, the kernels and swapfile are decrypted all at once.

    • Ooops@feddit.org
      2·
      4 hours ago

      OP seems to use the systemd hooks anyway. And with them all disks get decrypted with the first given password (or at least try and only ask for additional passwords if that fails). So it’s not neccessary anymore to have everything on the root partition. Several encrypted with the same password will do. (For example I unlock a classic swap partition and 3 differently sized disks creating one btrfs raid1 for root with one password.)