Re: 2.6.3-mm1

[Andrew Morton <akpm@osdl.org>]

Andi Kleen <ak@suse.de> wrote:
>
> Andrew Morton <akpm@osdl.org> writes:
> 
> > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.3/2.6.3-mm1/
> > 
> > - Added the dm-crypt driver: a crypto layer for device-mapper.
> > 
> >   People need to test and use this please.  There is documentation at
> >   http://www.saout.de/misc/dm-crypt/.
> > 
> >   We should get this tested and merged up.  We can then remove the nasty
> >   bio remapping code from the loop driver.  This will remove the current
> >   ordering guarantees which the loop driver provides for journalled
> >   filesystems.  ie: ext3 on cryptoloop will no longer be crash-proof.
> > 
> >   After that we should remove cryptoloop altogether.
> > 
> >   It's a bit late but cyptoloop hasn't been there for long anyway and it
> >   doesn't even work right with highmem systems (that part is fixed in -mm).
> 
> Is it guaranteed that this thing will be disk format compatible to cryptoloop? 
> (mainly in IVs and crypto algorithms)

Allegedly.  Of course, doing this will simply retain crypto-loop's security
weaknesses.

> While 2.3 and 2.4 have broken the on disk format of crypto loop several
> times (each time to a new "improved and ultimately perfect format")
> I don't think that's acceptable for a mature OS anymore.

Well I guess people are free to do that sort of thing with out-of-kernel
patches.

One question which needs to be adressed is whether dm-crypt adequately
addresses crypto-loop's security weaknesses, and if so, how one should set
it up to do so.