test.php script like this
// Look at random integers in 0 thru 999
php test.php 1 0 999 | less
// Look at random UUIDs
php test.php 2 | less
To statistically test for randomness of the function outputs, install
There are packages called
dieharder on OS X Homebrew, Ubuntu and Debian. Others can compile the source.
Dieharder takes a long time but very thorough. With LibreSSL it's OK, otherwise allow plenty of
time. The UUID test and all the
randomInt() tests are horribly slow.
// Test randomBytes() with 8192-byte length by sending the output to dieharder
$ php test.php 3 8192 | dieharder -g 200 -a
// Test `randomInt()` with max possible range by converting to 4 or 8-byte strings
$ php test.php 4 | dieharder -g 200 -a
// Test `randomInt()` with range 0 to 255 and random offset, convert to 1-byte strings before output
$ php test.php 5 1 | dieharder -g 200 -a
// Test `randomInt()` with range 0 to 256^3-1 and random offset, convert to 3-byte strings before output
$ php test.php 5 3 | dieharder -g 200 -a
// Convert the random substrings of UUIDs to bytes
$ php test.php 6 | dieharder -g 200 -a
On OS X 10.10.5 and PHP 5.6.16 with LibreSSL 2.3.1
$ php test.php 3 8192 | pv -s 10g -S > /dev/null
10GiB 0:00:25 [ 405MiB/s]
Without the complex
preg_match() stuff it goes up to 435 MiB/s. OpenBSD should be fast too.
Probably also NetBSD since 7.0.
On the same OS X machine I see 18.5 MiB/s with PHP 7.0 or with PHP 5.6 using mcrypt or
New stuff in this Gist
/dev/urandom – that's the rate of OS X's Yarrow RNG. On Linux I get 14.5 MiB/s.
All files except
randomStuff.php are original in this
Gist and have the following copyright and license.
Copyright (c) 2016, Tom Worster firstname.lastname@example.org
Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
Modified Yii 2.0 code in this Gist
I extracted the code in
randomStuff.php from Yii 2.0, hence that file
has its following copyright and license. See also
The Yii framework is free software. It is released under the terms of
the following BSD License.
Copyright © 2008 by Yii Software LLC (http://www.yiisoft.com)
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
- Neither the name of Yii Software LLC nor the names of its
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.