Re: Hibernation considerations

david
2007-07-17T17:49:52Z

On Tue, 17 Jul 2007, Dr. David Alan Gilbert wrote:

> * david@lang.hm (david@lang.hm) wrote:
>> On Mon, 16 Jul 2007, Rafael J. Wysocki wrote:
>
>>> Encryption is possible with both the userland hibernation (aka uswsusp) and
>>> TuxOnIce (formerly known as suspend2). Still, I don't consider it as a
>>> "must
>>> have" feature for a framework to be generally useful (many users don't use
>>> it
>>> anyway).
>>
>> he's talking about the main system useing an encrypted device/partition,
>> not the hibernate image being stored encrypted.
>>
>> This would require the main system 'forget' the keys when it does the
>> hinbernate and prompt for it again during the wake-up phase.
>
> Indeed - although as I say I really don't know what you would do with
> apps using the mounts at that point. Still it seems like a
> sensible requrest from the security side.

along the same lines, it would probably be a good idea to have the ability
for a system to re-ask for the pass phrase periodicly while the system is
running.

I see two possible approaches to these issues.

1. implement the periodic re-request capability, and when going into
hibernate time-out any known pass phrases.

this is a lot of work overall, but the suspend portion is trivial so there
would not be any suspend surprises.

2. flush the keyring on hibernate and have the resume process re-populate
it (either by pokeing directly into the memory, or by providing a table
that the resuming kernel reads from during wake-up to re-populate it)

this is less work, but it's all suspend related so it will get less
testing.

David Lang