dyne
LUKS header detaching
Should we implement LUKS header detaching from freshly locked tombs? Should it be a default?
An option for storing the header could be keeping it in the tomb key itself.
I am in favor of this as it would improve tomb's security and resilience, since one can more easily backup keys instead of the tomb and the integrity of headers is vital to access the tomb.
It is a rather delicate change that should be 100% retrocompatible with older tombs.
There will be the need to extend the range of information embedded "key header", which is right now sometimes present to specify pbkdf2 configuration. It will make keys bigger (up to 5Kb) which may impact qrcode generation and image steganography, while I'm not sure we should consider a compression algo for the 4Kb LUKS header (which alone is 4 times bigger than a key right now).
These are just some initial considerations for now, will follow up with more or organise this section better on a new edit. This change will go into Tomb 3, for which I'm creating a milestone.
It's this one: https://github.com/kriswebdev/cryptsetup-deluks
Keep in mind it's probably not been reviewed by anyone yet.