[dm-crypt] keys from RAM dumps, hibernation files

Heinz Diehl htd+ml at fritha.org
Fri Nov 14 08:06:45 CET 2014


On 13.11.2014, Lars Winterfeld wrote: 

> What they say about their method is only that it "acquires protection
> keys from RAM dumps, hibernation files". Now I wonder, how does this
> attack work exactly and how vulnerable is cryptsetup against it in a
> linux environment?

Whole disk encryption only protects your data when your computer is
off. Thus, there's no memory dump to catch. 
 
> Suppose THEY have the device in their hands.
 
> I guess the attack is easiest when I suspended to disk, because all
> information needed for decryption (of the mounted crypt volumes) is
> stored in plain on the disk?

Don't do that. Of course, it depends on the level of security you want
to have, and your threat model.
 
> When I suspend to RAM and they wake the device up again, they need to
> hack the login screen?

In general, when an adversary can get physical access to your running
machine, all bets are off. You can regard this machine as compromized.



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