From: Linus Torvalds <torvalds@linux-foundation.org>
To: Oliver Neukum <oliver@neukum.org>
Cc: security@kernel.org, Linux@hera.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
James Morris <jmorris@namei.org>, de Ven <arjan@infradead.org>,
Roland McGrath <roland@redhat.com>,
List <linux-kernel@vger.kernel.org>,
Arjan@hera.kernel.org, stable@kernel.org,
Dave Jones <davej@redhat.com>,
linux-security-module@vger.kernel.org, mingo@redhat.com,
Eric Paris <eparis@redhat.com>, Matt Mackall <mpm@selenic.com>,
Alan@hera.kernel.org, Jake Edge <jake@lwn.net>,
Cox <alan@lxorguk.ukuu.org.uk>,
"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [Security] [patch] random: make get_random_int() more random
Date: Sat, 16 May 2009 09:17:25 -0700 (PDT) [thread overview]
Message-ID: <alpine.LFD.2.01.0905160911400.3301@localhost.localdomain> (raw)
In-Reply-To: <alpine.LFD.2.01.0905160854570.3301@localhost.localdomain>
On Sat, 16 May 2009, Linus Torvalds wrote:
>
> So "one of X known functions" does not help
Side note - here the keyword is "X known functions". If the function
simply isn't known at all, you've now made it harder by a _much_ higher
factor. If the function is any good (ie doesn't leave any patterns to
guess what function it is), you really basically have to first solve that
independent problem.
And the space of possible functions is pretty damn large, even if you
start with some assumption ("some combination of known good cryptographic
hashes + some unknown seeding algorithm and data").
So practically speaking, nobody ever cracks those things without somehow
decoding the function itself (through doing something like disassembling
obfuscated code).
Linus
next prev parent reply other threads:[~2009-05-16 16:19 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-04 18:51 [PATCH] proc: avoid information leaks to non-privileged processes Jake Edge
2009-05-04 19:00 ` [Security] " Linus Torvalds
2009-05-04 19:51 ` Arjan van de Ven
2009-05-04 20:20 ` Eric W. Biederman
2009-05-04 22:24 ` Linus Torvalds
2009-05-04 23:26 ` Arjan van de Ven
2009-05-04 23:54 ` Linus Torvalds
2009-05-05 7:51 ` Eric W. Biederman
2009-05-05 15:17 ` Linus Torvalds
2009-05-05 15:35 ` Linus Torvalds
2009-05-05 16:18 ` Matt Mackall
2009-05-05 16:10 ` Matt Mackall
2009-05-05 5:50 ` Matt Mackall
2009-05-05 6:31 ` Ingo Molnar
2009-05-05 8:14 ` Eric W. Biederman
2009-05-05 19:52 ` Ingo Molnar
2009-05-05 20:22 ` Matt Mackall
2009-05-05 21:20 ` Eric W. Biederman
2009-05-06 10:33 ` Ingo Molnar
2009-05-06 10:30 ` Ingo Molnar
2009-05-06 16:25 ` Matt Mackall
2009-05-06 16:48 ` Linus Torvalds
2009-05-06 17:57 ` Matt Mackall
2009-05-07 0:50 ` Matt Mackall
2009-05-07 15:02 ` Ingo Molnar
2009-05-07 18:14 ` Matt Mackall
2009-05-07 18:21 ` Ingo Molnar
2009-05-07 18:41 ` Ingo Molnar
2009-05-07 19:24 ` Matt Mackall
2009-05-07 15:16 ` Florian Weimer
2009-05-07 16:55 ` Matt Mackall
2009-05-07 17:53 ` Linus Torvalds
2009-05-07 18:42 ` Matt Mackall
2009-05-06 20:09 ` [patch] random: make get_random_int() more random Ingo Molnar
2009-05-06 20:41 ` Matt Mackall
2009-05-06 20:51 ` Ingo Molnar
2009-05-06 21:10 ` Matt Mackall
2009-05-06 21:24 ` Ingo Molnar
2009-05-14 22:47 ` Jake Edge
2009-05-14 22:55 ` [Security] " Linus Torvalds
2009-05-15 13:47 ` Ingo Molnar
2009-05-15 15:10 ` Jake Edge
2009-05-16 10:00 ` Willy Tarreau
2009-05-16 10:39 ` Ingo Molnar
2009-05-16 12:02 ` Eric W. Biederman
2009-05-16 14:00 ` Michael S. Zick
2009-05-16 14:28 ` Michael S. Zick
2009-05-16 14:57 ` Arjan van de Ven
2009-05-16 15:09 ` Michael S. Zick
2009-05-16 14:32 ` Matt Mackall
2009-05-16 13:58 ` Willy Tarreau
2009-05-16 15:23 ` Linus Torvalds
2009-05-16 15:47 ` Willy Tarreau
2009-05-16 15:54 ` Oliver Neukum
2009-05-16 16:05 ` Linus Torvalds
2009-05-16 16:17 ` Linus Torvalds [this message]
2009-05-15 1:16 ` Américo Wang
2009-05-06 20:25 ` [Security] [PATCH] proc: avoid information leaks to non-privileged processes Ingo Molnar
2009-05-06 20:52 ` Matt Mackall
2009-05-05 8:58 ` Andi Kleen
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