1 <?php

     2 /**

     3  * Random_* Compatibility Library 

     4  * for using the new PHP 7 random_* API in PHP 5 projects

     5  * 

     6  * The MIT License (MIT)

     7  * 

     8  * Copyright (c) 2015 Paragon Initiative Enterprises

     9  * 

    10  * Permission is hereby granted, free of charge, to any person obtaining a copy

    11  * of this software and associated documentation files (the "Software"), to deal

    12  * in the Software without restriction, including without limitation the rights

    13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

    14  * copies of the Software, and to permit persons to whom the Software is

    15  * furnished to do so, subject to the following conditions:

    16  * 

    17  * The above copyright notice and this permission notice shall be included in

    18  * all copies or substantial portions of the Software.

    19  * 

    20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

    21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

    22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

    23  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

    24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

    25  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

    26  * SOFTWARE.

    27  */

    28 

    29 

    30 if ( ! is_callable( 'random_bytes' ) ):

    31 /**

    32  * Powered by ext/mcrypt (and thankfully NOT libmcrypt)

    33  * 

    34  * @ref https://bugs.php.net/bug.php?id=55169

    35  * @ref https://github.com/php/php-src/blob/c568ffe5171d942161fc8dda066bce844bdef676/ext/mcrypt/mcrypt.c#L1321-L1386

    36  * 

    37  * @param int $bytes

    38  * 

    39  * @throws Exception

    40  * 

    41  * @return string

    42  */

    43 function random_bytes($bytes)

    44 {

    45     try {

    46         $bytes = RandomCompat_intval($bytes);

    47     } catch (TypeError $ex) {

    48         throw new TypeError(

    49             'random_bytes(): $bytes must be an integer'

    50         );

    51     }

    52 

    53     if ($bytes < 1) {

    54         throw new Error(

    55             'Length must be greater than 0'

    56         );

    57     }

    58 

    59     $buf = @mcrypt_create_iv($bytes, MCRYPT_DEV_URANDOM);

    60     if (

    61         $buf !== false

    62         &&

    63         RandomCompat_strlen($buf) === $bytes

    64     ) {

    65         /**

    66          * Return our random entropy buffer here:

    67          */

    68         return $buf;

    69     }

    70 

    71     /**

    72      * If we reach here, PHP has failed us.

    73      */

    74     throw new Exception(

    75         'Could not gather sufficient random data'

    76     );

    77 }

    78 endif;