[dm-crypt] Where is the entered password stored?

Arno Wagner arno at wagner.name
Mon Dec 8 13:45:29 CET 2014


Hi,

this is really not something cryptsetup does. There is some
application or script that your distribution uses to 
implement this functionality, so you have to look there.

Cryptsetup stores the master-key in kernel-memory while the 
LUKS container is mapped (open) and wipes it from memory on 
luksClose. Cryptsetup never stores the passphrase.

You can get the master-key from a mapped device from the
kernel (as root), though. FAQ Item 6.10 explains how.
(http://code.google.com/p/cryptsetup/wiki/FrequentlyAskedQuestions)

Arno

On Mon, Dec 08, 2014 at 13:06:14 CET, Jian-Ming Zheng wrote:
> Hi,
> 
> When I attach a hard disk with LUKS encrypted partition to a Linux
> machine, a window will pop up and a password or passphrase is required
> to unlock the encrypted partition. In addition to forget passphrase
> immediately, I can choose to 1) remember passphrase until I logout or
> 2) remember forever. I am curious about where the entered passphrase
> is kept in the two cases?
> 
> Thanks.
> _______________________________________________
> dm-crypt mailing list
> dm-crypt at saout.de
> http://www.saout.de/mailman/listinfo/dm-crypt

-- 
Arno Wagner,     Dr. sc. techn., Dipl. Inform.,    Email: arno at wagner.name
GnuPG: ID: CB5D9718  FP: 12D6 C03B 1B30 33BB 13CF  B774 E35C 5FA1 CB5D 9718
----
A good decision is based on knowledge and not on numbers. -- Plato

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


More information about the dm-crypt mailing list