Re: [dm-crypt] reinstallation

[Sam <test532@codingninjas.org>]

That is unfortunate.
Well, give us a bit more information. Try doing the following:

cryptsetup luksDump /dev/sda2

(this will just output some info on what encryption algorithm your partition 
uses)

Then paste what it says into an email. Just the first 6 lines would be enough 
for me (upto and including "Hash spec:").

Ie:

LUKS header information for /dev/sda7

Version:        1
Cipher name:    aes
Cipher mode:    xts-plain
Hash spec:      sha1

Regards,
Sam

> I tried:
>
> modprobe dm_mod
> ioctl: 4.11.0-ioctl (2006-10-12) initialized: dm-devel@redhat.com
> modprobe crypto_blkcipher
> FATAL: Module crypto_blkcipher not found
> modprobe cbc
> modprobe dm_crypt
> modprobe aes_generic
> FATAL: Module aes_generic not found
> modprobe aes_i586
> cryptsetup luksOpen /dev/sda2 tresor
> Command failed: No setup backend available
>
> Best regards
> Rainer
>
>
> -------- Original-Nachricht --------
>
> > Datum: Tue, 11 Aug 2009 18:39:19 -0400
> > Von: Sam <samm@sammaloney.com>
> > An: dm-crypt@saout.de
> > CC: RaMaier@gmx.de
> > Betreff: Re: [dm-crypt] reinstallation
> >
> > Your problem is then with your Linux installation.
> >
> > I would be guessing that your device mapper is not setup properly, or
> > best case is simply not loaded by default for some reason.
> >
> > Try this as root:
> >
> > modprobe dm_mod
> >
> > That will load the device mapper module (driver) and should be enough.
> >
> > Then try your luksOpen command again.
> >
> > If you get the same errror, then try also all of these in addition to the
> > dm_mod:
> >
> > modprobe crypto_blkcipher
> > modprobe cbc
> > modprobe dm_crypt
> > modprobe aes_generic
> > modprobe aes_i586
> >
> > Some of these might fail with an error, but that could be just that they
> > are
> > already built into your kernel (and thus are permanently loaded -- that
> > is okay).
> >
> > Now try the luksOpen again. If it still doesn't work, then I do not know.
> > However, it really should have worked by now at least.
> >
> > If it did work: note that you will need to add these commands to your
> > /etc/init.d/boot.local file (just add them to the end just like you typed
> > them
> > in the terminal). This will cause them to be loaded upon startup each
> > time.
> >
> > Hope that helps.
> >
> > Sam
> >
> > > When I just enter
> > > cryptsetup luksOpen /dev/sda2 tresor
> > > I get the reply:
> > > Command failed: No setup backend available
> > >
> > > I guess it somehow has a relation to the mapper.
> > > Any idea ?
> > >
> > > Best regards
> > > Rainer
> > >
> > >
> > > -------- Original-Nachricht --------
> > >
> > > > Datum: Tue, 11 Aug 2009 23:42:29 +0200
> > > > Von: Arno Wagner <arno@wagner.name>
> > > > An: RaMaier@gmx.de
> > > > Betreff: Re: [dm-crypt] reinstallation
> > > >
> > > > I suspect luksFormat wipes the LUKS superblock and creates
> > > > a new one, i.e. all data is permanently lost. mkfs.ext3
> > > > will overwrote the filesystem metadata, i.e. the filesystem
> > > > structure is lost.
> > > >
> > > > However
> > > >
> > > > > cryptsetup luksOpen /dev/sda2 tresor
> > > > > mount /dev/mapper/tresor /tresor
> > > >
> > > > should work, with sda2 replaced with whatever the
> > > > LUKS container now is in. Basically you just do what you
> > > > did before to access (not create) the device, just
> > > > with a (potentially) different device identifier.
> > > >
> > > > As to preventing partition loss, make a sector-wise
> > > > backup copy, e.g. with dd or dd_rescue before risking it.
> > > >
> > > > Arno
> > > >
> > > > On Tue, Aug 11, 2009 at 11:25:16PM +0200, RaMaier@gmx.de wrote:
> > > > > Hi Hannes,
> > > > > in the documents I keep. I found that I had encrypted /dev/sda2.
> > > > > The
> > > >
> > > > procedure I recorded was:
> > > > > umount /dev/sda2
> > > > > cryptsetup luksFormat /dev/sda2
> > > > > cryptsetup luksOpen /dev/sda2 tresor
> > > > > mkfs.ext3 /dev/mapper/tresor
> > > > > mount /dev/mapper/tresor /tresor
> > > > >
> > > > > What will happen if I repeat the steps ?
> > > > > Should I just leave the mkfs.ext3 out ?
> > > > > Would I be able to access my old data again ?
> > > > > What does lufsFormat really do ? Format the partition ?
> > > > > As I staded the data is pretty valuable to me.
> > > > >
> > > > > thanks for your help.
> > > > > Best regards
> > > > > Rainer
> > > > >
> > > > >
> > > > > -------- Original-Nachricht --------
> > > > >
> > > > > > Datum: Tue, 11 Aug 2009 16:01:56 +0200
> > > > > > Von: Hannes Erven <h.e@gmx.at>
> > > > > > An: Rainer Maier <RaMaier@gmx.de>
> > > > > > CC: dm-crypt@saout.de
> > > > > > Betreff: Re: [dm-crypt] reinstallation
> > > > > >
> > > > > > Hi Rainer,
> > > > > >
> > > > > > > How can I reinstall LUKS on my new Debian (Lenny)?
> > > > > >
> > > > > > I guess the debian (and thus cryptsetup) installations on your
> > > > > > old machine weren't that up to date, right?
> > > > > >
> > > > > > With the new debian lenny, you don't need to install anything:
> >
> > LUKS
> >
> > > > > > is already included in the default cryptsetup package you should
> > > > > > already have installed
> >
> > (http://packages.debian.org/lenny/cryptsetup
> >
> > > > > > ).
> > > > > >
> > > > > > >>From http://code.google.com/p/cryptsetup/:
> > > > > >
> > > > > > "The former version of cryptsetup only had low-level operations
> >
> > for
> >
> > > > > > dm-crypt ready, and around version cryptsetup-luks 1.0.5 was
> >
> > renamed
> >
> > > > to
> > > >
> > > > > > be the official version of cryptsetup. "
> > > > > >
> > > > > > You still might have to change your old scripts, if you have
> > > > > > some,
> >
> > to
> >
> > > > > > just call cryptsetup instead of cryptsetup-luks .
> > > > > >
> > > > > >
> > > > > > HTH, best regards
> > > > > >
> > > > > > 	-hannes
> > > > > >
> > > > > >
> > > > > >
> > > > > > _______________________________________________
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> > > > > > dm-crypt@saout.de
> > > > > > http://www.saout.de/mailman/listinfo/dm-crypt
> > > >
> > > > -
> > > >
> > > > > sicherer, schneller und einfacher!
> > > > > http://portal.gmx.net/de/go/atbrowser
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