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From: Daniel Micay <danielmicay@gmail.com>
To: kernel-hardening@lists.openwall.com,
	"Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: hannes@stressinduktion.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org,
	jeanphilippe.aumasson@gmail.com, djb@cr.yp.to,
	torvalds@linux-foundation.org, ebiggers3@gmail.com
Subject: Re: [kernel-hardening] Re: [PATCH v2 1/4] siphash: add cryptographically secure hashtable function
Date: Thu, 15 Dec 2016 03:15:55 -0500	[thread overview]
Message-ID: <1481789755.1114.7.camel@gmail.com> (raw)
In-Reply-To: <20161215075746.GA14699@gondor.apana.org.au>

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On Thu, 2016-12-15 at 15:57 +0800, Herbert Xu wrote:
> Jason A. Donenfeld <Jason@zx2c4.com> wrote:
> > 
> > Siphash needs a random secret key, yes. The point is that the hash
> > function remains secure so long as the secret key is kept secret.
> > Other functions can't make the same guarantee, and so nervous
> > periodic
> > key rotation is necessary, but in most cases nothing is done, and so
> > things just leak over time.
> 
> Actually those users that use rhashtable now have a much more
> sophisticated defence against these attacks, dyanmic rehashing
> when bucket length exceeds a preset limit.
> 
> Cheers,

Key independent collisions won't be mitigated by picking a new secret.

A simple solution with clear security properties is ideal.

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  reply	other threads:[~2016-12-15  8:15 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-14  3:59 [PATCH v2 1/4] siphash: add cryptographically secure hashtable function Jason A. Donenfeld
2016-12-14  3:59 ` [PATCH v2 2/4] siphash: add convenience functions for jhash converts Jason A. Donenfeld
2016-12-14  3:59 ` [PATCH v2 3/4] secure_seq: use siphash24 instead of md5_transform Jason A. Donenfeld
2016-12-14 12:53   ` Jason A. Donenfeld
2016-12-14 13:16     ` Hannes Frederic Sowa
2016-12-14 13:44       ` Jason A. Donenfeld
2016-12-14 14:47         ` David Laight
2016-12-14 17:49           ` Jason A. Donenfeld
2016-12-14 17:56     ` David Miller
2016-12-14 18:06       ` Jason A. Donenfeld
2016-12-14 19:22         ` Hannes Frederic Sowa
2016-12-14 19:38           ` Jason A. Donenfeld
2016-12-14 20:27             ` Hannes Frederic Sowa
2016-12-14 20:12     ` Tom Herbert
2016-12-14 21:01       ` Jason A. Donenfeld
2016-12-14  3:59 ` [PATCH v2 4/4] random: use siphash24 instead of md5 for get_random_int/long Jason A. Donenfeld
2016-12-14 11:21 ` [PATCH v2 1/4] siphash: add cryptographically secure hashtable function Hannes Frederic Sowa
2016-12-14 13:10   ` Jason A. Donenfeld
2016-12-14 15:09     ` Hannes Frederic Sowa
2016-12-14 19:47       ` Jason A. Donenfeld
2016-12-15  7:57     ` Herbert Xu
2016-12-15  8:15       ` Daniel Micay [this message]
2016-12-14 12:46 ` Jason A. Donenfeld
2016-12-14 22:03   ` Hannes Frederic Sowa
2016-12-14 23:29     ` Jason A. Donenfeld
2016-12-15  8:31       ` Hannes Frederic Sowa
2016-12-15 11:04     ` David Laight
2016-12-15 12:23       ` Hannes Frederic Sowa
2016-12-15 12:28         ` David Laight
2016-12-15 12:50           ` Hannes Frederic Sowa
2016-12-15 13:56             ` David Laight
2016-12-15 14:56               ` Hannes Frederic Sowa
2016-12-15 15:41                 ` David Laight
2016-12-15 15:53                   ` Hannes Frederic Sowa
2016-12-15 18:50                     ` Jason A. Donenfeld
2016-12-15 20:31                       ` Hannes Frederic Sowa
2016-12-15 20:43                         ` Jason A. Donenfeld
2016-12-15 21:04                           ` Peter Zijlstra
2016-12-15 21:09                             ` Hannes Frederic Sowa
2016-12-15 21:17                           ` Hannes Frederic Sowa
2016-12-15 21:09                       ` Peter Zijlstra
2016-12-15 21:11                         ` [kernel-hardening] " Jason A. Donenfeld
2016-12-15 21:14                           ` Linus Torvalds
2016-12-14 18:46 ` [PATCH v3 1/3] " Jason A. Donenfeld
2016-12-14 18:46   ` [PATCH v3 2/3] secure_seq: use siphash24 instead of md5_transform Jason A. Donenfeld
2016-12-14 21:44     ` kbuild test robot
2016-12-14 18:46   ` [PATCH v3 3/3] random: use siphash24 instead of md5 for get_random_int/long Jason A. Donenfeld
2016-12-14 21:56     ` kbuild test robot
2016-12-14 21:57     ` kbuild test robot
2016-12-15 10:14     ` David Laight
2016-12-15 18:51       ` Jason A. Donenfeld
2016-12-14 19:18   ` [PATCH v3 1/3] siphash: add cryptographically secure hashtable function Tom Herbert
2016-12-14 19:35     ` Jason A. Donenfeld
2016-12-14 20:55       ` Jason A. Donenfeld
2016-12-14 21:35         ` Tom Herbert
2016-12-14 22:56           ` Jason A. Donenfeld
2016-12-14 23:14             ` Tom Herbert
2016-12-14 23:17               ` Jason A. Donenfeld
2016-12-18  0:06                 ` Christian Kujau
2016-12-14 23:30             ` Linus Torvalds
2016-12-14 23:34               ` Jason A. Donenfeld
2016-12-15  0:10                 ` Linus Torvalds
2016-12-15 10:22                   ` David Laight
2016-12-14 21:15   ` kbuild test robot
2016-12-14 21:21     ` Jason A. Donenfeld
2016-12-15  1:46   ` [PATCH v4 1/4] " Jason A. Donenfeld
2016-12-15  1:46     ` [PATCH v4 2/4] siphash: add N[qd]word helpers Jason A. Donenfeld
2016-12-15  1:46     ` [PATCH v4 3/4] secure_seq: use siphash instead of md5_transform Jason A. Donenfeld
2016-12-15  1:46     ` [PATCH v4 4/4] random: use siphash instead of MD5 for get_random_int/long Jason A. Donenfeld
2016-12-15  4:23     ` [PATCH v4 1/4] siphash: add cryptographically secure hashtable function kbuild test robot

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