Re: [dm-crypt] Password is not accepted

From: "Karl O. Pinc" <kop@meme.com>
To: dm-crypt@saout.de
Subject: Re: [dm-crypt] Password is not accepted
Date: Tue, 20 Sep 2011 21:03:56 -0500	[thread overview]
Message-ID: <1316570636.4663.3@mofo> (raw)
In-Reply-To: <20110920234354.GA30110@tansi.org> (from arno@wagner.name on Tue Sep 20 18:43:54 2011)

On 09/20/2011 06:43:54 PM, Arno Wagner wrote:
> Very strange indeed. Is this repeatable?

This is strictly an FYI in case anyone's interested.

This seems like a good time to mention a similar strange
issue.  I've chalked it up to too-new hardware and have
yet to try with the latest kernel.org kernel, but running
Debian Squeeze, with either the stock 2.6.32 kernel or the
backports 2.6.39 kernel I see failure to enter the
luks password.  This is on an Acer Aspire One D255E-13647
with a manufacture date of 2011-01.

This is all driven by the initramfs.  What happens is that,
sometimes, the screen goes black for perhaps 15 or more
seconds starting about 3 or 4 seconds after the luks
password prompt.  Attempts to enter the password or portion
thereof during this time always result in failure.
I believe I've seen the same problem without the screen
going black as well.  If I wait a long time to enter the
password all is well.

In any case I've not tracked the details closely and 
am waiting until I get around to trying a newer kernel 
to see if the problem goes away.

> Meybe a thermal issue with RAM, CPU or PSU that has the
> password iterations fail when cold and work when warmed 
> up? For CPU/RAM this would be strance as cold CMOS 
> circuits work better than hot ones. For the PSU, it
> is possible that failing capacitors reconstiture a bit
> after warm up. Anyways, sounds like a hardware issue to 
> me.
> 
> Arno
> 
> On Tue, Sep 20, 2011 at 09:13:32PM +0200, Ask Me wrote:
> > Hi
> > 
> > Now I'm having a strange problem. First I thought that I was 
> getting
> old and had forgot my password but now it happens more then once.
> > 
> > When I reboot my computer and try to open my encrypted device with
> "cryptsetup luksOpen /dev/vg_home/home_private lv_encr" I get the
> message that my password is not accepted.
> > But if I reboot it again and wait for a few minutes and try the
> command again it's successful. 
> > Is it possible that it needs time to activate? It's a LVM array. 
> But
> my /tmp and swap is encrypted at boot and they works (I hope =) )
> > 
> > My setup is
> > sda1 -> LVM -> dm_crypt -> xfs
> > 
> > //Martin
> 
> > _______________________________________________
> > 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
> ----
> 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 
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> 

Karl <kop@meme.com>
Free Software:  "You don't pay back, you pay forward."
                 -- Robert A. Heinlein