Date: Thu, 14 Apr 2005 18:38:01 +1000
To: Andy Isaacson <adi@hexapodia.org>
Cc: Pavel Machek <pavel@ucw.cz>, Andreas Steinmetz <ast@domdv.de>, rjw@sisk.pl,
       linux-kernel@vger.kernel.org
Subject: Re: encrypted swap (was Re: [PATCH encrypted swsusp 1/3] core functionality)
Message-ID: <20050414083801.GA13540@gondor.apana.org.au>
References: <20050413233904.GA31174@gondor.apana.org.au> <20050414083119.GB24892@hexapodia.org>
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From: Herbert Xu <herbert@gondor.apana.org.au>
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On Thu, Apr 14, 2005 at 01:31:19AM -0700, Andy Isaacson wrote:
> 
> Does dmcrypt have a simple operation mode like OpenBSD's encrypted swap?
> I want to be able to 'sysctl -w kernel.swap_crypt=1' and get

It's not that easy however the distros can make it so that it's as
simple as running one command to enable/disable it.

>  * pages are encrypted as they're written to swap

Yep.

>  * the key is automatically regenerated every 2 hours (or whatever); as
>    pages encrypted under the old key age out, it can be freed eventually

This'll require changes to dmcrypt but it's doable.

>  * I don't have to manage keys, choose algorithms, futz with /etc/fstab,
>    figure out complex configs for /dev/loopN, etc

You don't need to worry about keys unless you want to read from the swap
after a reboot, i.e., swsusp.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
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