Re: [PATCH v9 06/19] x86: Add early SHA-1 support for Secure Launch early measurements

Jarkko Sakkinen
2024-08-19T18:05:56Z

On Fri Aug 16, 2024 at 9:41 PM EEST, Matthew Garrett wrote:
> On Fri, Aug 16, 2024 at 02:22:04PM +0300, Jarkko Sakkinen wrote:
>
> > For (any) non-legacy features we can choose, which choices we choose to
> > support, and which we do not. This is not an oppositive view just saying
> > how it is, and platforms set of choices is not a selling argument.
>
> NIST still permits the use of SHA-1 until 2030, and the most significant
> demonstrated weaknesses in it don't seem applicable to the use case
> here. We certainly shouldn't encourage any new uses of it, and anyone
> who's able to use SHA-2 should be doing that instead, but it feels like
> people are arguing about not supporting hardware that exists in the real
> world for vibes reasons rather than it being a realistically attackable
> weakness (and if we really *are* that concerned about SHA-1, why are we
> still supporting TPM 1.2 at all?)

We are life-supporting TPM 1.2 as long as necessary but neither the
support is extended nor new features will gain TPM 1.2 support. So
that is at least my policy for that feature.

BR, Jarkko