Messages in this thread |  | | | Date | Fri, 27 Jul 2012 19:48:45 -0700 | | From | "H. Peter Anvin" <> | | Subject | Re: [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.
|  |