lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date:	Fri, 18 Jul 2014 02:23:56 -0400
From:	Theodore Ts'o <>
To:	"H. Peter Anvin" <>
Cc:	Linux Kernel Developers List <>,,
	Linus Torvalds <>
Subject: Re: [PATCH] random: limit the contribution of the hw rng to at most

On Thu, Jul 17, 2014 at 04:33:36PM -0700, H. Peter Anvin wrote:
> I just want to make sure we don't negatively impact the real security of
> users because of "optics".  We already have a lot of problems with
> people extracting long-living keys from /dev/urandom because /dev/random
> is too slow.

With a system with RDRAND, we're mixing arch_get_rand_long() as part
of the extraction process (as the seed for the SHA's IV).  So if you
trust RDRAND, then using /dev/urandom even when the entropy count is
zero is going to be secure.  If you don't trust RDRAND, then the
RDSEED entropy accounting is going to be extremely disturbing.

So the only way that we could be impacting the "real security" of
users, would be if RDRAND was back-doored, but RDSEED wasn't.  And
that doesn't seem like a terribly likely scenario to me, but what do I
know?  :-)

						- Ted
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists