Equivalent of --integrity-recalculate

Marc SCHAEFER <[email protected]> Sat, 10 May 2025 17:51:17 +0200
Newsgroups dev.linux.lists.cryptsetup
Message-ID <[email protected]>
Hello,

If you create a cryptsetup/luks device with integrity with:

   cryptsetup luksFormat -q --type luks2 --integrity hmac-sha256 $dev

and then open it:

   cryptsetup open $dev backup-copy

you then get, according to lsblk, two additional devices:

   - backup-copy (the transparently decrypted/encrypting volume)

   - backup-copy_dif (the integrity device)

(which is similar, AFAIK, as when you use dm-integrity with LVM)

If you create an integrity device separately, you get a

   integritysetup --integrity-recalculate open $dev integrity

command which allows to recalculate the integrity blocks.

I don't think cryptsetup has this option (*); is there a way to
do it anyway?  Or maybe remove the backup-copy_dif and
re-add it?

Thank you for any pointer.

(*) it looks there is a feature request pending
       https://gitlab.com/cryptsetup/cryptsetup/-/issues/854