Re: [dm-crypt] recovering forgotten passwords for 2 LVs

[Arno Wagner <arno@wagner.name>]

On Mon, Aug 22, 2011 at 06:33:30PM -0400, ken wrote:
[...] 
> Yves, thanks for replying.
> 
> This setup worked fine for years without changing anything on it.  I'm
> fairly certain that there are two logical volumes on /dev/sda5, both
> encrypted.  As said, when I booted the system up, I was prompted for two
> passphrases (one for each filesystem).
> 
> 
> Does this tell us anything?
> 
> # cryptsetup luksDump /dev/sda5
> LUKS header information for /dev/sda5
> 
> Version:        1
> Cipher name:    aes
[...]

It does. /dev/sda5 has a LUKS container at the start with
one passphrase active. For password breaking attempts, it 
does not matter that there are some LVM mappings. I advise 
to just ignore any LVM stuff for the moment and to run your 
password guessing attempts against /dev/sda5. 

You will possibly not get you data, but the password checking 
will be good, unless that thing was created using 
decrypt_derived or the like. I doubt that, as then you 
should have been asked only for one password.

Once you have the password recovered, you should be able
to do a normal boot.

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
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans

If it's in the news, don't worry about it.  The very definition of 
"news" is "something that hardly ever happens." -- Bruce Schneier