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Date: Tue, 17 Jan 2017 16:59:24 +0200
To: Yasuo Ohgaki <yohgaki@ohgaki.net>
Cc: internals@lists.php.net
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Subject: Re: [PHP-DEV] Re: Improving mt_rand() seed
From: lauri.kentta@gmail.com (=?UTF-8?Q?Lauri_Kentt=C3=A4?=)

On 2017-01-17 16:18, Lauri Kenttä wrote:
> On 2017-01-17 02:34, Yasuo Ohgaki wrote:
>> Set state somewhere between MT rand's 2^19937−1 cycle.
> 
> This is exactly what my patch does.

Or, to be honest, my patch provides 2^19936 possible states,
which should be more than enough.

To get all 2^19937−1, you would need to get one more bit of
entropy (2^19936 to 2^19937) and then check that the state is
not all zeros (which is the −1 in 2^19937−1). That's certainly
not worth the trouble, so I just set that one "extra" bit to 1.
(MT doesn't work if the state is all zeros.)

-- 
Lauri Kenttä