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

Matthew Garrett
2024-08-16T18:49:01Z

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?)