From: Hannes Frederic Sowa <hannes@stressinduktion.org>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>,
kernel-hardening@lists.openwall.com,
"Theodore Ts'o" <tytso@mit.edu>,
George Spelvin <linux@sciencehorizons.net>,
Andi Kleen <ak@linux.intel.com>,
David Miller <davem@davemloft.net>,
David Laight <David.Laight@aculab.com>,
"Daniel J . Bernstein" <djb@cr.yp.to>,
Eric Biggers <ebiggers3@gmail.com>,
"Jean-Philippe Aumasson" <jeanphilippe.aumasson@gmail.com>,
Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Andy Lutomirski <luto@amacapital.net>,
Netdev <netdev@vger.kernel.org>,
Tom Herbert <tom@herbertland.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Vegard Nossum <vegard.nossum@gmail.com>
Subject: Re: [kernel-hardening] Re: [PATCH v5 1/4] siphash: add cryptographically secure PRF
Date: Fri, 16 Dec 2016 22:15:23 +0100 [thread overview]
Message-ID: <1481922923.2204853.821591377.2CD623CB@webmail.messagingengine.com> (raw)
In-Reply-To: <CAHmME9pz=syTiLXUsbXFyGdbGK6pxbnU+TVLDkbYiTa-9+sckQ@mail.gmail.com>
On Fri, Dec 16, 2016, at 22:01, Jason A. Donenfeld wrote:
> Yes, on x86-64. But on i386 chacha20 incurs nearly the same kind of
> slowdown as siphash, so I expect the comparison to be more or less
> equal. There's another thing I really didn't like about your chacha20
> approach which is that it uses the /dev/urandom pool, which means
> various things need to kick in in the background to refill this.
> Additionally, having to refill the buffered chacha output every 32 or
> so longs isn't nice. These things together make for inconsistent and
> hard to understand general operating system performance, because
> get_random_long is called at every process startup for ASLR. So, in
> the end, I believe there's another reason for going with the siphash
> approach: deterministic performance.
*Hust*, so from where do you generate your key for siphash if called
early from ASLR?
Bye,
Hannes
next prev parent reply other threads:[~2016-12-16 21:15 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-16 21:01 Jason A. Donenfeld
2016-12-16 21:15 ` Hannes Frederic Sowa [this message]
-- strict thread matches above, loose matches on Subject: below --
2016-12-17 1:39 Jason A. Donenfeld
2016-12-17 2:15 ` George Spelvin
2016-12-17 15:41 ` [kernel-hardening] " Theodore Ts'o
2016-12-17 16:14 ` Jeffrey Walton
2016-12-19 17:21 ` Jason A. Donenfeld
2016-12-16 20:49 Jason A. Donenfeld
2016-12-16 21:25 ` George Spelvin
2016-12-16 21:31 ` [kernel-hardening] " Jason A. Donenfeld
2016-12-16 22:41 ` George Spelvin
[not found] <CAGiyFdfmiCMyHvAg=5sGh8KjBBrF0Wb4Qf=JLzJqUAx4yFSS3Q@mail.gmail.com>
2016-12-16 3:46 ` George Spelvin
[not found] ` <CAGiyFdd6_LVzUUfFcaqMyub1c2WPvWUzAQDCH+Aza-_t6mvmXg@mail.gmail.com>
2016-12-16 12:39 ` Jason A. Donenfeld
2016-12-16 19:47 ` Tom Herbert
2016-12-16 20:44 ` [kernel-hardening] " Daniel Micay
2016-12-16 21:09 ` Jason A. Donenfeld
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