lkml.org 
[lkml]   [2012]   [Jul]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] random: mix in architectural randomness in extract_buf()
On 07/27/2012 07:39 PM, Theodore Ts'o wrote:
> Ok, I'll add this patch to the random tree. I've modified the commit
> message a bit since the speed advertisement of RDRAND is rather
> pointless --- processes aren't generating session keys or long term
> keys at a high rate, and programs can't count on /dev/random being
> super fast and having unlimited entropy, since for most platforms and
> even most x86 CPU's deployed in service today, this isn't true --- and
> making your userspace program depond upon /dev/random in such a way
> that it only works on Ivy Bridge CPU's might be good for Intel from a
> vendor lock-in perspective, but it's really bad, non-portable
> programming style.
>
> Also, in the future arch_get_random_long() will almost certainly be
> hooked up for other architectures, so putting an extended
> advertisement for RDRAND really isn't appropriate.

Thanks. /dev/random vs /dev/urandom is orthogonal to this; as you note
we still haven't changed the entropy accounting. I am thinking that
that is probably better left to rngd at least until RDSEED is available
(or the equivalent on other hardware.)

-hpa


--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.



\
 
 \ /
  Last update: 2012-07-28 05:21    [from the cache]
©2003-2011 Jasper Spaans