[dm-crypt] [ANNOUNCE] LUKSMeta

Arno Wagner arno at wagner.name
Fri May 13 18:23:40 CEST 2016

Interesting idea.

Do you analyze the header to make sure the gap is there and
of expected size and the LUKS version is known to the library? 
What happens if somebody did a non-default configuration?
What happens with a different header than LUKS v1?


On Fri, May 13, 2016 at 18:01:06 CEST, Nathaniel McCallum wrote:
> https://github.com/latchset/luksmeta
> Hi everyone! Several projects that I am working on or related to
> require the ability to store some small metadata that is accessable
> before the LUKS volume is unlocked. Since this was not possible with
> LUKSv1, and we couldn't wait until LUKSv2, we created a small library
> called LUKSMeta.
> This simple library allows an application developer to store some
> metadata in the gap in the LUKSv1 header (between the end of the
> keyslots and the start of the payloadOffset). There are up to eight
> "slots" of metadata, similar to the eight keyslots of LUKS. Each slot
> is typed by a 16-byte UUID, so that applications don't stomp on each
> others' data. Both the LUKSMeta header and the data in each slot is
> checksummed (CRC32c) to detect data corruption.
> There are four simple functions:
> * luksmeta_init() - Write the LUKSMeta header to disk
> * luksmeta_get() - Read data/uuid from a LUKSMeta slot
> * luksmeta_set() - Write data/uuid to a LUKSMeta slot
> * luksmeta_del() - Clear (zero) a LUKSMeta slot
> More detailed documentation is available in the header:
> https://github.com/latchset/luksmeta/blob/master/luksmeta.h
> I have not made the first release, but I would like to do so soon. I
> welcome your review/feedback. Thanks!
> Nathaniel
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Arno Wagner,     Dr. sc. techn., Dipl. Inform.,    Email: arno at wagner.name
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