[dm-crypt] loop file with partition problems

[dm-crypt] loop file with partition problems

[Giovanni Di Stasi]

Hi everyone,

I am having problems accessing a partition I have created on a file. I 
have never managed to mount it after reboot.
I am using Debian (testing).

This is what I did:

# sudo -i
# echo aes >> /etc/modules
# echo dm_mod >> /etc/modules
# echo dm_crypt >> /etc/modules
# dd if=/dev/urandom of=.encrypted bs=1024 count=500000
# sudo cryptsetup -y create crypt .encrypted
# echo "crypt /home/giovanni/.encrypted none none" >> /etc/crypttab
# sudo mkfs.ext4 /dev/mapper/crypt
# mkdir /home/giovanni/cip
# chown giovanni:giovanni /home/giovanni/cip/
# sudo mount /dev/mapper/crypt /home/giovanni/cip
# ls /home/giovanni/cip/
# sudo umount /home/giovanni/cip
# sudo mount /dev/mapper/crypt /home/giovanni/cip

After rebooted, I don't really know how to mount my partition.
I have tried this:

# sudo -i
# cryptsetup luksOpen .encrypted crypt
Device /dev/loop0 is not a valid LUKS device.

Did I lost all my data as I suspect? If so, why?

Thanks a lot,
Giovanni

Re: [dm-crypt] loop file with partition problems

[Arno Wagner]

On Wed, Feb 29, 2012 at 05:26:03PM +0100, Giovanni Di Stasi wrote:
> Hi everyone,
> 
> I am having problems accessing a partition I have created on a file.
> I have never managed to mount it after reboot.
> I am using Debian (testing).
> 
> This is what I did:
> 
> # sudo -i
> # echo aes >> /etc/modules
> # echo dm_mod >> /etc/modules
> # echo dm_crypt >> /etc/modules
> # dd if=/dev/urandom of=.encrypted bs=1024 count=500000
> # sudo cryptsetup -y create crypt .encrypted
> # echo "crypt /home/giovanni/.encrypted none none" >> /etc/crypttab
> # sudo mkfs.ext4 /dev/mapper/crypt
> # mkdir /home/giovanni/cip
> # chown giovanni:giovanni /home/giovanni/cip/
> # sudo mount /dev/mapper/crypt /home/giovanni/cip
> # ls /home/giovanni/cip/
> # sudo umount /home/giovanni/cip
> # sudo mount /dev/mapper/crypt /home/giovanni/cip
> 
> After rebooted, I don't really know how to mount my partition.
> I have tried this:
> 
> # sudo -i
> # cryptsetup luksOpen .encrypted crypt
> Device /dev/loop0 is not a valid LUKS device.
> 
> Did I lost all my data as I suspect? If so, why?

You are confusing plain dm-crypt and LUKS. You created the 
crypto-container (which is not a partition but a whole 
decive here) as plain dm-crypt and are trying to map it
as LUKS. These two are different and not compatible.

Try this:

 cryptsetup create crypt .encrypted
 mount /dev/mapper/crypt /home/giovanni/cip

Arno
-- 
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@wagner.name 
GnuPG:  ID: 1E25338F  FP: 0C30 5782 9D93 F785 E79C  0296 797F 6B50 1E25 338F
----
One of the painful things about our time is that those who feel certainty 
are stupid, and those with any imagination and understanding are filled 
with doubt and indecision. -- Bertrand Russell 

Re: [dm-crypt] loop file with partition problems

[Milan Broz]

On 02/29/2012 05:26 PM, Giovanni Di Stasi wrote:

Here you are creating plain container (did you mean luksFormat in fact?)
> # sudo cryptsetup -y create crypt .encrypted

and here you are trying to open LUKS...
> # cryptsetup luksOpen .encrypted crypt

so try
sudo cryptsetup -y create crypt .encrypted

which will just recreate the mapping (create just set up mapping,
it doesn't format anything)

Milan

Re: [dm-crypt] loop file with partition problems

[Giovanni Di Stasi]

Il 29/02/2012 17:41, Milan Broz ha scritto:
> On 02/29/2012 05:26 PM, Giovanni Di Stasi wrote:
>
> Here you are creating plain container (did you mean luksFormat in fact?)
>> # sudo cryptsetup -y create crypt .encrypted
>
> and here you are trying to open LUKS...
>> # cryptsetup luksOpen .encrypted crypt
>
> so try
> sudo cryptsetup -y create crypt .encrypted
>
> which will just recreate the mapping (create just set up mapping,
> it doesn't format anything)
>
> Milan
Worked!! Thanks!!

But I was asked the password twice... how come?
What if I type a different password?

Thanks,
Giovanni

Re: [dm-crypt] loop file with partition problems

[Arno Wagner]

The -y option is useful to use initially to make sure
you have the right password when you format.
It causes cryptsetup to ask the password twice.

For more documentation on the options, run
  cryptsetup -h
and refer to the man-page. 

Arno 

On Wed, Feb 29, 2012 at 06:57:33PM +0100, Giovanni Di Stasi wrote:
> Il 29/02/2012 17:41, Milan Broz ha scritto:
> >On 02/29/2012 05:26 PM, Giovanni Di Stasi wrote:
> >
> >Here you are creating plain container (did you mean luksFormat in fact?)
> >># sudo cryptsetup -y create crypt .encrypted
> >
> >and here you are trying to open LUKS...
> >># cryptsetup luksOpen .encrypted crypt
> >
> >so try
> >sudo cryptsetup -y create crypt .encrypted
> >
> >which will just recreate the mapping (create just set up mapping,
> >it doesn't format anything)
> >
> >Milan
> Worked!! Thanks!!
> 
> But I was asked the password twice... how come?
> What if I type a different password?
> 
> Thanks,
> Giovanni
> _______________________________________________
> dm-crypt mailing list
> dm-crypt@saout.de
> http://www.saout.de/mailman/listinfo/dm-crypt
> 

-- 
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@wagner.name 
GnuPG:  ID: 1E25338F  FP: 0C30 5782 9D93 F785 E79C  0296 797F 6B50 1E25 338F
----
One of the painful things about our time is that those who feel certainty 
are stupid, and those with any imagination and understanding are filled 
with doubt and indecision. -- Bertrand Russell