Re: [PATCH v36 23/24] docs: x86/sgx: Document SGX micro architecture and kernel internals

From: Pavel Machek
Date: Sat Aug 08 2020 - 18:18:16 EST


Hi!

> Good morning, I hope the week is progressing well for everyone.
>
> > > CPUs starting from Icelake use Total Memory Encryption (TME) in
> > > the place of MEE. TME throws away the Merkle tree, which means
> > > losing integrity and anti-replay protection but also enables
> > > variable size memory pools for EPC. Using this attack for
> > > benefit would require an interposer on the system bus.
>
> > It is not exactly clear what "this attack" means.
>
> In the new world that is SGX, 'this attack', roughly means that
> enclaves are susceptible to the same security threats that would be
> faced if you were running TLS/HTTPS or SSH without packet checksums
> and replay avoidance/detection mechanisms in place.

Umm, ssh w/o checksums would be rather dangerous, no? As in... if I can guess what you
are typing, I can make you type something else.

Anyway, it would be nice to somehow fix the document. It talks about "this attack"
without talking about any attack before, which is bad style.

Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html