On Tue May 14, 2024 at 5:41 PM EEST, Ignat Korchagin wrote: > On Tue, May 14, 2024 at 3:00 PM Jarkko Sakkinen <jarkko@xxxxxxxxxx> wrote: > > > > On Tue May 14, 2024 at 4:11 PM EEST, Ignat Korchagin wrote: > > > For example, a cheap NAS box with no internal storage (disks connected > > > externally via USB). We want: > > > * disks to be encrypted and decryptable only by this NAS box > > > > So how this differs from LUKS2 style, which also systemd supports where > > the encryption key is anchored to PCR's? If I took hard drive out of my > > Linux box, I could not decrypt it in another machine because of this. > > It differs with the fact that the disk has a clearly identifiable > LUKS2 header, which tells an adversary that this is a disk with some > data that is encrypted. With derived keys and plain dm-crypt mode > there is no LUKS header, so it is not possible to tell if it is an > encrypted disk or a disk with just random data. Additionally, if I > accidentally wipe the sector with the LUKS2 header - all my data is > lost (because the data encryption key from the header is lost). With > derived keys I can always decrypt at least some data, if the disk is > available. I figured most of this out myself and sent a follow-up but yeah thnaks for confirming my toughts. I get this part now. Follow-ups to my follow-up... BR, Jarkko
