lkml.org 
[lkml]   [2019]   [Aug]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Non-random RDRAND Re: [PATCH] x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h
On Thu 2019-08-15 11:12:24, Theodore Y. Ts'o wrote:
> On Thu, Aug 15, 2019 at 01:24:35AM +0200, Pavel Machek wrote:
> > Burn it with fire!
> >
> > I mean... people were afraid RDRAND would be backdoored, and you now
> > confirm ... it indeed _is_ backdoored? /., here's news for you!
>
> To be fair to AMD, I wouldn't call it a backdoor. Hanlon's razor is
> applicable here:
>
> "Never attribute to malice that which can be adequately
> explained by neglect."

> (Sometimes other words are used instead of neglect, but i'm trying to
> be nice.)

You are right, I thought it was returning values with low entropy, and
it returns ~0 (so -- really really low entropy :-) and can't be
clasified as a backdoor.

Anyway, AMD is _not_ doing good job right now.

I'd expect:

a) CVE reference

b) real fix; if BIOS can init the rng, so can kernel

Pavel

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2019-08-16 11:08    [W:0.052 / U:3.212 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site