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From: David Laight <David.Laight@ACULAB.COM>
To: "'Jason A. Donenfeld'" <Jason@zx2c4.com>,
	Netdev <netdev@vger.kernel.org>,
	"kernel-hardening@lists.openwall.com" 
	<kernel-hardening@lists.openwall.com>,
	LKML <linux-kernel@vger.kernel.org>,
	"linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
	Ted Tso <tytso@mit.edu>,
	Hannes Frederic Sowa <hannes@stressinduktion.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Eric Biggers <ebiggers3@gmail.com>,
	Tom Herbert <tom@herbertland.com>,
	"George Spelvin" <linux@sciencehorizons.net>,
	Vegard Nossum <vegard.nossum@gmail.com>,
	"ak@linux.intel.com" <ak@linux.intel.com>,
	"davem@davemloft.net" <davem@davemloft.net>,
	"luto@amacapital.net" <luto@amacapital.net>
Subject: RE: [PATCH v5 2/4] siphash: add Nu{32,64} helpers
Date: Fri, 16 Dec 2016 10:39:35 +0000	[thread overview]
Message-ID: <063D6719AE5E284EB5DD2968C1650D6DB0240EFA@AcuExch.aculab.com> (raw)
In-Reply-To: <20161215203003.31989-3-Jason@zx2c4.com>

From: Jason A. Donenfeld
> Sent: 15 December 2016 20:30
> These restore parity with the jhash interface by providing high
> performance helpers for common input sizes.
...
> +#define PREAMBLE(len) \
> +	u64 v0 = 0x736f6d6570736575ULL; \
> +	u64 v1 = 0x646f72616e646f6dULL; \
> +	u64 v2 = 0x6c7967656e657261ULL; \
> +	u64 v3 = 0x7465646279746573ULL; \
> +	u64 b = ((u64)len) << 56; \
> +	v3 ^= key[1]; \
> +	v2 ^= key[0]; \
> +	v1 ^= key[1]; \
> +	v0 ^= key[0];

Isn't that equivalent to:
	v0 = key[0];
	v1 = key[1];
	v2 = key[0] ^ (0x736f6d6570736575ULL ^ 0x646f72616e646f6dULL);
	v3 = key[1] ^ (0x646f72616e646f6dULL ^ 0x7465646279746573ULL);

Those constants also look like ASCII strings.
What cryptographic analysis has been done on the values?

	David

  reply	other threads:[~2016-12-16 10:40 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 [this message]
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
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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