Re: cgd (encrypted disk) support in bootblocks (Was: summer of code - scrub feature)

[David Brownlee <abs%NetBSD.org@localhost>]

On Mon, 23 Mar 2009, Todd Vierling wrote:

> On Mon, Mar 23, 2009 at 9:12 AM, David Brownlee <abs%netbsd.org@localhost> 
> wrote:
> >        Converting a running system to an encryped filesystem without
> >        requiring a dump/restore is a very nice additional feature, but
> >        I think NetBSD would really benefit from 'just' the cgd support
> >        in the bootblocks and passing the relevant data across to the
> >        kernel so it can get a cgd encrypted root filesystem...
>
> Works for workstations, if the bootblocks have passphrase entry (and
> better yet, cgd decrypt support to load the kernel itself from an
> encrypted root); that would work much like other full-disk encryption
> systems.

        I think that would be the ideal case for any mahine which
        doesn't require unattended reboot - the only unencrypted
        data on the disk would be the bootblocks and some cdg config
        (which may well be written into the bootblocks). Once installed
        it should be transparent to the user including updating kernels
        and anything other than bootblocks :)

> Without something like TPM, doesn't solve the unattended server
> problem, though perhaps that does require a more complex solution
> (such as a ramdisk or small root partition, over which / is remounted)
> to allow the key to be stored in a more flexible manner.
>
> Collectively this sounds more like two projects to me, though the
> latter could suffice for both cases, for a first stab at it.  The
> latter is also less low-level code and more scripting work (and
> perhaps crunchgen for space), which may make multiplatform support
> less painful.  Mentors' mileage may vary.

        Could you clarify how the latter would work - is the intention
        to allow the system to boot up to a point where the administrator
        can connect in to finish cgd configuration and remount?

        I can see the utility of both, and would be very happy with
        either :)

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