Re: Dual-Licensing Linux Kernel with GPL V2 and GPL V3

From: david
Date: Thu Jun 21 2007 - 13:51:09 EST


On Thu, 21 Jun 2007, Lennart Sorensen wrote:

On Thu, Jun 21, 2007 at 10:26:04AM -0700, david@xxxxxxx wrote:
the bios doesn't have enough capability to talk to the outside world for
updates.

Of course, although perhaps it could. More likely my thought was that
the service when it decides to download an update, would include the
updated bios image and put it on the boot drive where the existing bios
can find it. No signature needs to be added to the boot drive or
kernel, just checksums in the bios image.

what tivo actually does is very similar to this

they encode into the bios the ability to check a checksum/signature for
the kernel+boot filesystem and if they don't match look to see if there is
another kernel+boot filesystem available

then software on the boot filesystem checks to see if the rest of the
system has been tampered with before it mounts /

you snippede the bit about not knowing how to stop it

the GPLv3 is trying to do this.

Perhaps they should just explicitly say that then.

they call the section the anti-tivoization, how much more explicit can they get?

David Lang

by the way, just in case anyone is misunderstanding me. I don't believe for a moment that all these anti-tamper features actually work in the real world (the PS3 hacking kits are proof of the lengths people will go to to make the 'hard' hardware-level hacking trivial to do) but the approach needs to be at secure modulo hardware tampering or software bugs.

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