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  * If the libsodium PHP extension is loaded, we'll use it above any other

    32  * solution.

    33  *

    34  * libsodium-php project:

    35  * @ref https://github.com/jedisct1/libsodium-php

    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     /**

    60      * \Sodium\randombytes_buf() doesn't allow more than 2147483647 bytes to be

    61      * generated in one invocation.

    62      */

    63     if ($bytes > 2147483647) {

    64         $buf = '';

    65         for ($i = 0; $i < $bytes; $i += 1073741824) {

    66             $n = ($bytes - $i) > 1073741824

    67                 ? 1073741824

    68                 : $bytes - $i;

    69             $buf .= \Sodium\randombytes_buf($n);

    70         }

    71     } else {

    72         $buf = \Sodium\randombytes_buf($bytes);

    73     }

    74 

    75     if ($buf !== false) {

    76         if (RandomCompat_strlen($buf) === $bytes) {

    77             return $buf;

    78         }

    79     }

    80 

    81     /**

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

    83      */

    84     throw new Exception(

    85         'Could not gather sufficient random data'

    86     );

    87 }

    88 endif;