[dm-crypt] Debian Boot

[dm-crypt] Debian Boot

[Stéphane Bailleul]

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Hi  My PC just crashed, the hard drive were encrypted ( I don't exactly know the method) but it was during the debian squeeze 64 bits installation, one of the optionMy Hard drive with a separate  / and Home /dev/sda1 was the //dev/sda5 was the home it seems that something went very bad on this computer, after turning it on nothing shows on the screen after the bios.Using the rescue option on my CD, I have been able to mount SDA1, I was trying to mount SDA5 but can notusing cryptsetup luksOpen is says that it is not a valid device there is no mapper in /sda1/dev Is there a way to mount sda5 and unencrypt the data ?I still have the password  I hope there is a solution CheersStephane   		 	   		  

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Re: [dm-crypt] Debian Boot

[Arno Wagner]

On Wed, Oct 24, 2012 at 04:05:34PM +0000, St?phane Bailleul wrote:
> 
> 
> Hi  My PC just crashed, the hard drive were encrypted ( I don't exactly
> know the method) but it was during the debian squeeze 64 bits
> installation, one of the optionMy Hard drive with a separate / and Home
> /dev/sda1 was the //dev/sda5 was the home it seems that something went
> very bad on this computer, after turning it on nothing shows on the screen
> after the bios.Using the rescue option on my CD, I have been able to mount
> SDA1, I was trying to mount SDA5 but can notusing cryptsetup luksOpen is
> says that it is not a valid device there is no mapper in /sda1/dev Is
> there a way to mount sda5 and unencrypt the data ?I still have the
> password I hope there is a solution CheersStephane

Ok, lets start with the advice for this situation from 
the FAQ: First, calm down.

Some questions:

1.What exactly did you do? 

2. Did you install squeeze 64bit over some other installation 
   you had before? What kind of other installation was that?

3. What was encrypted before and how? You seems to think sda5 was
   encrypted with LUKS, why do you think that? (What do you
   know about it that tells you it was encrypted?) 

4. Was sda1 encrypted before and is it still, or does it now 
   have a new, unencrypted squeeze 64bit installation on it?

4. Did you create/manipulate any partitions or file-systems?

Arno
-- 
Arno Wagner,    Dr. sc. techn., Dipl. Inform.,   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] Debian Boot

[Yves-Alexis Perez]

On mer., 2012-10-24 at 18:33 +0200, Arno Wagner wrote:
> On Wed, Oct 24, 2012 at 04:05:34PM +0000, St?phane Bailleul wrote:
> > 
> > 
> > Hi  My PC just crashed, the hard drive were encrypted ( I don't exactly
> > know the method) but it was during the debian squeeze 64 bits
> > installation, one of the optionMy Hard drive with a separate / and Home
> > /dev/sda1 was the //dev/sda5 was the home it seems that something went
> > very bad on this computer, after turning it on nothing shows on the screen
> > after the bios.Using the rescue option on my CD, I have been able to mount
> > SDA1, I was trying to mount SDA5 but can notusing cryptsetup luksOpen is
> > says that it is not a valid device there is no mapper in /sda1/dev Is
> > there a way to mount sda5 and unencrypt the data ?I still have the
> > password I hope there is a solution CheersStephane
> 
> Ok, lets start with the advice for this situation from 
> the FAQ: First, calm down.
> 
> Some questions:
> 
> 1.What exactly did you do? 
> 
> 2. Did you install squeeze 64bit over some other installation 
>    you had before? What kind of other installation was that?
> 
> 3. What was encrypted before and how? You seems to think sda5 was
>    encrypted with LUKS, why do you think that? (What do you
>    know about it that tells you it was encrypted?) 

Few precisions on Debian installer use of encryption. The “default”
encrypted setup is done using LVM, as:

/dev/sda1 → /boot
/dev/sda5 (logical partition, even though there's still room for other
primary ones) → luks partition (using, afair, aes-essiv but I'm not
completely sure) mapped as /dev/mapper/sda5_crypt
/dev/mapper/sda5_crypt is a physical volume for LVM on top of which are
a volume group (name from the hostname) and logical volumes
(for /, /home and swap)

So, in theory, cryptsetup luksDump /dev/sda5 should return the header
for the encrypted partition.

Regards,
-- 
Yves-Alexis

Re: [dm-crypt] Debian Boot

[Arno Wagner]

On Thu, Oct 25, 2012 at 10:07:13AM +0200, Yves-Alexis Perez wrote:
>
> Few precisions on Debian installer use of encryption. The ???default???
> encrypted setup is done using LVM, as:
> 
> /dev/sda1 ??? /boot
> /dev/sda5 (logical partition, even though there's still room for other
> primary ones) ??? luks partition (using, afair, aes-essiv but I'm not
> completely sure) mapped as /dev/mapper/sda5_crypt
> /dev/mapper/sda5_crypt is a physical volume for LVM on top of which are
> a volume group (name from the hostname) and logical volumes
> (for /, /home and swap)
> 
> So, in theory, cryptsetup luksDump /dev/sda5 should return the header
> for the encrypted partition.

About what I expected. He has by now sent me hexdumps of
sda5 and other partition starts, there is not even a trace
of a LUKS header in there. I think this is a complete loss.

Arno
-- 
Arno Wagner,    Dr. sc. techn., Dipl. Inform.,   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