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From: Szabolcs Nagy <nsz@port70.net>
To: musl@lists.openwall.com
Subject: Re: [PATCH] Add support for mkostemp, mkstemps and mkostemps
Date: Sat, 2 Feb 2013 23:11:11 +0100	[thread overview]
Message-ID: <20130202221110.GM6181@port70.net> (raw)
In-Reply-To: <510D6E30.60206@barfooze.de>

* John Spencer <maillist-musl@barfooze.de> [2013-02-02 20:51:12 +0100]:
> +	unsigned long r = ts.tv_nsec + (uintptr_t)&ts / 16 + (uintptr_t)x6;

i recommend a multiplier here, eg. with

r = nsec*1664525 + A;

if only the last few bits of nsec are uniform random then
the top bits of A are not immediately known from r

..only the top bits of A*4276115653 can be known
(1664525*4276115653 == 1 mod 2^32)

and that's probably less useful for an attacker


  parent reply	other threads:[~2013-02-02 22:11 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-02 18:45 Anthony G. Basile
2013-02-02 19:51 ` John Spencer
2013-02-02 19:59   ` John Spencer
2013-02-02 22:11   ` Szabolcs Nagy [this message]
2013-02-02 20:14 ` Szabolcs Nagy
2013-02-02 20:38   ` Anthony G. Basile
2013-02-02 22:22     ` Szabolcs Nagy
  -- strict thread matches above, loose matches on Subject: below --
2013-02-02 21:15 Anthony G. Basile
2013-02-02 21:17 ` Anthony G. Basile
2013-02-03  3:30 ` Rich Felker
2013-01-28  5:06 Anthony G. Basile
2013-01-28  8:47 ` John Spencer
2013-01-28  9:37 ` Szabolcs Nagy
2013-01-28 17:33   ` Szabolcs Nagy
2013-01-29 23:16   ` Anthony G. Basile
2013-01-30  7:21     ` Rich Felker
2013-01-30  7:59       ` Hardy Falk
2013-01-30 13:45         ` Szabolcs Nagy
2013-01-30 16:51           ` Rich Felker
2013-01-30 19:12             ` Szabolcs Nagy
2013-01-30 19:22               ` Rich Felker
2013-01-31  0:28                 ` Szabolcs Nagy
2013-01-28 16:33 ` Rich Felker
2013-02-02  3:48 ` Rich Felker
2013-02-02 18:46   ` Anthony G. Basile
2013-01-28  2:36 Anthony G. Basile
2013-01-28  5:01 ` Anthony G. Basile

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