Re: [GIT PULL] x86/txt for v2.6.32

[Pavel Machek]

On Wed 2009-09-30 10:16:55, Wang, Shane wrote:
> Arjan van de Ven wrote:
> > On Tue, 29 Sep 2009 19:13:18 +0200
> > Pavel Machek <pavel@xxxxxx> wrote:
> > 
> >> Ok, and what prevents me from commenting out the MAC checking code?
> >> 
> > 
> > because the bios verified some code that verified the kernel which
> > includes the MAC checking code .. as part of returning from S3 ?
> 
> Yes, S3 sleep/resume cause another cycle to build the measured environment.
> i.e. SINIT will verify tboot, tboot will verify kernel mem, kernel will verify userspace mem.
> If you comment out the MAC checking code in any party, the chain will lost and S3 resume will fail.
> 

Ok, that means that you are protecting integrity but not secrecy?
Should that be written down in documentation, along with threat model?

So I modify the RAM content so that BIOS does not think measured
environment existed before suspend?
									Pavel

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