Re: detached LUKS header size
Arno Wagner <[email protected]>
| Newsgroups | gmane.linux.kernel.device-mapper.dm-crypt |
|---|---|
| Message-ID | <[email protected]> |
If you do that, you kill the security model of LUKS. The anti-forensic stripes are not some gadget, they are central. Also, the key-slots are the stripes. There are no 4kB you can take out and reconstruct the key from them. That said, I think if you have an issue with 10MB extra today and are willing to sacrifice security to get rid of them, then you are doing it massively wrong. Maybe just do without encryption and security, it clearly is not your first priority.... Regards, Arno On Sat, Nov 23, 2019 at 06:43:56 CET, Fourhundred Thecat wrote: > Hello, > > I am using full-disk encryption with detached LUKS header. > > The LUKS header file itself is stored on an initrd image which I boot > from USB, and then I decrypt the cryptsetup partition on my disk and > chroot into it. > > The initrd system that I boot is very minimal, around 8MB in size. > > The LUKS image, being 2MB, is making the initrd image needlessly bigger. > > And the new LUKS2 format seems to use even larger header (10MB ?) > > >From what I understand, the keyslots themselves only use up 4KB of > space, and the rest is used for "antiforensic stripes". > > This is probably a good idea when LUKS header is stored on disk together > with the cryptsetup partition. > > But when using detached header, which is never stored on disk, this > makes less sense > > Thus my question: > > is it possible, somehow, to reduce the size of the LUKS header to > absolute minimum (4KB ?), when I don't need the antiforensic stripes ? > > thank you, > _______________________________________________ > dm-crypt mailing list > [email protected] > https://www.saout.de/mailman/listinfo/dm-crypt -- Arno Wagner, Dr. sc. techn., Dipl. Inform., Email: [email protected] GnuPG: ID: CB5D9718 FP: 12D6 C03B 1B30 33BB 13CF B774 E35C 5FA1 CB5D 9718 ---- A good decision is based on knowledge and not on numbers. -- Plato If it's in the news, don't worry about it. The very definition of "news" is "something that hardly ever happens." -- Bruce Schneier _______________________________________________ dm-crypt mailing list [email protected] https://www.saout.de/mailman/listinfo/dm-crypt