Re: [patch] random: make get_random_int() more random

From: Matt Mackall <mpm@selenic.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Arjan van de Ven <arjan@infradead.org>, Jake Edge <jake@lwn.net>,
	security@kernel.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	James Morris <jmorris@namei.org>,
	linux-security-module@vger.kernel.org,
	Eric Paris <eparis@redhat.com>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>,
	Roland McGrath <roland@redhat.com>,
	mingo@redhat.com, Andrew Morton <akpm@linux-foundation.org>,
	Greg KH <greg@kroah.com>, Dave Jones <davej@redhat.com>
Subject: Re: [patch] random: make get_random_int() more random
Date: Wed, 6 May 2009 15:41:57 -0500	[thread overview]
Message-ID: <20090506204156.GB31071@waste.org> (raw)
In-Reply-To: <20090506200954.GA21484@elte.hu>

On Wed, May 06, 2009 at 10:09:54PM +0200, Ingo Molnar wrote:
> I then ran the FIPS randomness test over the first 20,000 bits [2.5K 
> data], which it passed:

That's proves nothing except that you have no idea what you're talking
about. People regularly break things that FIPS gives flying colors.
FIPS is nothing but a statistical sanity-check.

Do you need this to be publicly broken again by someone who actually knows
something about cryptanalysis before you'll accept that it's a bad
idea? If so, then please move the code out of random.c, so that I
don't have to share in your embarassment a second time.

-- 
Mathematics is the supreme nostalgia of our time.