From: Hannes Frederic Sowa <hannes@stressinduktion.org>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kernel-hardening@lists.openwall.com,
"Theodore Ts'o" <tytso@mit.edu>,
Andy Lutomirski <luto@amacapital.net>,
Netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
David Laight <David.Laight@aculab.com>,
Eric Dumazet <edumazet@google.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Eric Biggers <ebiggers3@gmail.com>,
Tom Herbert <tom@herbertland.com>,
Andi Kleen <ak@linux.intel.com>,
"David S. Miller" <davem@davemloft.net>,
Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
Subject: Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5
Date: Thu, 22 Dec 2016 16:51:40 +0100 [thread overview]
Message-ID: <1482421900.2673.3.camel@stressinduktion.org> (raw)
In-Reply-To: <CAHmME9ok8iWfZybyDki13v6Xf3usRet1y8oUcDcy+5YwkARQPA@mail.gmail.com>
On Thu, 2016-12-22 at 16:41 +0100, Jason A. Donenfeld wrote:
> Hi Hannes,
>
> On Thu, Dec 22, 2016 at 4:33 PM, Hannes Frederic Sowa
> <hannes@stressinduktion.org> wrote:
> > IPv6 you cannot touch anymore. The hashing algorithm is part of uAPI.
> > You don't want to give people new IPv6 addresses with the same stable
> > secret (across reboots) after a kernel upgrade. Maybe they lose
> > connectivity then and it is extra work?
>
> Ahh, too bad. So it goes.
If no other users survive we can put it into the ipv6 module.
> > The bpf hash stuff can be changed during this merge window, as it is
> > not yet in a released kernel. Albeit I would probably have preferred
> > something like sha256 here, which can be easily replicated by user
> > space tools (minus the problem of patching out references to not
> > hashable data, which must be zeroed).
>
> Oh, interesting, so time is of the essence then. Do you want to handle
> changing the new eBPF code to something not-SHA1 before it's too late,
> as part of a new patchset that can fast track itself to David? And
> then I can preserve my large series for the next merge window.
This algorithm should be a non-seeded algorithm, because the hashes
should be stable and verifiable by user space tooling. Thus this would
need a hashing algorithm that is hardened against pre-image
attacks/collision resistance, which siphash is not. I would prefer some
higher order SHA algorithm for that actually.
Bye,
Hannes
next prev parent reply other threads:[~2016-12-22 15:52 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-15 20:29 [PATCH v5 0/4] The SipHash Patchset Jason A. Donenfeld
2016-12-15 20:30 ` [PATCH v5 1/4] siphash: add cryptographically secure PRF Jason A. Donenfeld
2016-12-15 22:42 ` George Spelvin
2016-12-16 2:14 ` kbuild test robot
2016-12-17 14:55 ` Jeffrey Walton
2016-12-19 17:08 ` Jason A. Donenfeld
2016-12-15 20:30 ` [PATCH v5 2/4] siphash: add Nu{32,64} helpers Jason A. Donenfeld
2016-12-16 10:39 ` David Laight
2016-12-16 15:44 ` George Spelvin
2016-12-15 20:30 ` [PATCH v5 3/4] secure_seq: use SipHash in place of MD5 Jason A. Donenfeld
2016-12-16 9:59 ` David Laight
2016-12-16 15:57 ` Jason A. Donenfeld
2016-12-15 20:30 ` [PATCH v5 4/4] random: " Jason A. Donenfeld
2016-12-16 3:03 ` [PATCH v6 0/5] The SipHash Patchset Jason A. Donenfeld
2016-12-16 3:03 ` [PATCH v6 1/5] siphash: add cryptographically secure PRF Jason A. Donenfeld
2016-12-16 3:03 ` [PATCH v6 2/5] secure_seq: use SipHash in place of MD5 Jason A. Donenfeld
2016-12-16 3:03 ` [PATCH v6 3/5] random: " Jason A. Donenfeld
2016-12-16 21:31 ` Andy Lutomirski
2016-12-16 3:03 ` [PATCH v6 4/5] md5: remove from lib and only live in crypto Jason A. Donenfeld
2016-12-16 3:03 ` [PATCH v6 5/5] syncookies: use SipHash in place of SHA1 Jason A. Donenfeld
2016-12-21 23:02 ` [PATCH v7 0/6] The SipHash Patchset Jason A. Donenfeld
2016-12-21 23:02 ` [PATCH v7 1/6] siphash: add cryptographically secure PRF Jason A. Donenfeld
2016-12-22 1:40 ` Stephen Hemminger
2016-12-21 23:02 ` [PATCH v7 2/6] secure_seq: use SipHash in place of MD5 Jason A. Donenfeld
2016-12-21 23:02 ` [PATCH v7 3/6] random: " Jason A. Donenfeld
2016-12-21 23:13 ` Jason A. Donenfeld
2016-12-21 23:42 ` Andy Lutomirski
2016-12-22 2:07 ` Hannes Frederic Sowa
2016-12-22 2:09 ` Andy Lutomirski
2016-12-22 2:49 ` Jason A. Donenfeld
2016-12-22 3:12 ` Jason A. Donenfeld
2016-12-22 5:41 ` [kernel-hardening] " Theodore Ts'o
2016-12-22 6:03 ` Jason A. Donenfeld
2016-12-22 15:58 ` Theodore Ts'o
2016-12-22 16:16 ` Jason A. Donenfeld
2016-12-22 16:30 ` Theodore Ts'o
2016-12-22 16:36 ` Jason A. Donenfeld
2016-12-22 12:47 ` Hannes Frederic Sowa
2016-12-22 13:10 ` Jason A. Donenfeld
2016-12-22 15:05 ` Hannes Frederic Sowa
2016-12-22 15:12 ` Jason A. Donenfeld
2016-12-22 15:29 ` Jason A. Donenfeld
2016-12-22 15:33 ` Hannes Frederic Sowa
2016-12-22 15:41 ` Jason A. Donenfeld
2016-12-22 15:51 ` Hannes Frederic Sowa [this message]
2016-12-22 15:53 ` Jason A. Donenfeld
2016-12-22 15:54 ` Theodore Ts'o
2016-12-22 18:08 ` Hannes Frederic Sowa
2016-12-22 18:13 ` Jason A. Donenfeld
2016-12-22 19:50 ` Theodore Ts'o
2016-12-22 2:31 ` Jason A. Donenfeld
2016-12-21 23:02 ` [PATCH v7 4/6] md5: remove from lib and only live in crypto Jason A. Donenfeld
2016-12-21 23:02 ` [PATCH v7 5/6] syncookies: use SipHash in place of SHA1 Jason A. Donenfeld
2016-12-21 23:02 ` [PATCH v7 6/6] siphash: implement HalfSipHash1-3 for hash tables Jason A. Donenfeld
2016-12-22 0:46 ` Andi Kleen
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