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 if ( ! is_callable( 'random_bytes' ) ):

    30 /**

    31  * Windows with PHP < 5.3.0 will not have the function

    32  * openssl_random_pseudo_bytes() available, so let's use

    33  * CAPICOM to work around this deficiency.

    34  * 

    35  * @param int $bytes

    36  * 

    37  * @throws Exception

    38  * 

    39  * @return string

    40  */

    41 function random_bytes($bytes)

    42 {

    43     try {

    44         $bytes = RandomCompat_intval($bytes);

    45     } catch (TypeError $ex) {

    46         throw new TypeError(

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

    48         );

    49     }

    50 

    51     if ($bytes < 1) {

    52         throw new Error(

    53             'Length must be greater than 0'

    54         );

    55     }

    56 

    57     $buf = '';

    58     $util = new COM('CAPICOM.Utilities.1');

    59     $execCount = 0;

    60 

    61     /**

    62      * Let's not let it loop forever. If we run N times and fail to

    63      * get N bytes of random data, then CAPICOM has failed us.

    64      */

    65     do {

    66         $buf .= base64_decode($util->GetRandom($bytes, 0));

    67         if (RandomCompat_strlen($buf) >= $bytes) {

    68             /**

    69              * Return our random entropy buffer here:

    70              */

    71             return RandomCompat_substr($buf, 0, $bytes);

    72         }

    73         ++$execCount; 

    74     } while ($execCount < $bytes);

    75 

    76     /**

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

    78      */

    79     throw new Exception(

    80         'Could not gather sufficient random data'

    81     );

    82 }

    83 endif;