Voir aussi :

• https://gitlab.com/cryptsetup/cryptsetup/wikis/FrequentlyAskedQuestions#6-backup-and-data-recovery
• homectl
• Clevis / Tang Server

Add a new passphrase

cryptsetup luksAddKey /dev/nvme0n1p3

cryptsetup luksDump /dev/sda2

Source :

• upgrade your LUKS key derivation function
  • https://nantes.indymedia.org/posts/87395/une-lettre-divan-enferme-a-la-prison-de-villepinte-perquisitions-et-disques-durs-dechiffres/

lsblk
sudo cryptsetup luksHeaderBackup /dev/whatever --header-backup-file /tmp/luksheader

Copy that to a USB stick or something. If something goes wrong here you'll be able to boot a live image and run

sudo cryptsetup luksHeaderRestore /dev/whatever --header-backup-file luksheader

to restore it.

(Edit to add: Once everything is working, delete this backup! It contains the old weak key, and someone with it can potentially use that to brute force your disk encryption key using the old KDF even if you've updated the on-disk KDF.)

Next, run

sudo cryptsetup luksDump /dev/whatever

and look for the Version: line. If it's version 1, you need to update the header to LUKS2. Run

sudo cryptsetup convert /dev/whatever --type luks2

and follow the prompts. Make sure your system still boots, and if not go back and restore the backup of your header. Assuming everything is ok at this point, run

sudo cryptsetup luksDump /dev/whatever

again and look for the PBKDF: line in each keyslot (pay attention only to the keyslots, ignore any references to pbkdf2 that come after the Digests: line). If the PBKDF is either pbkdf2 or argon2i you should convert to argon2id. Run the following:

sudo cryptsetup luksConvertKey /dev/whatever --pbkdf argon2id

and follow the prompts. If you have multiple passwords associated with your drive you'll have multiple keyslots, and you'll need to repeat this for each password.

Distributions! You should really be handling this sort of thing on upgrade. People who installed their systems with your encryption defaults several years ago are now much less secure than people who perform a fresh install today. Please please please do something about this.