PHP Classes

File: lib/random_bytes_libsodium.php

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  Classes of Scott Arciszewski   random_compat   lib/random_bytes_libsodium.php   Download  
File: lib/random_bytes_libsodium.php
Role: Example script
Content type: text/plain
Description: Example script
Class: random_compat
Provide random_bytes and random_int functions
Author: By
Last change:
Date: 6 years ago
Size: 2,836 bytes
 

Contents

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<?php
/**
 * Random_* Compatibility Library
 * for using the new PHP 7 random_* API in PHP 5 projects
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2015 - 2017 Paragon Initiative Enterprises
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

if (!is_callable('random_bytes')) {
   
/**
     * If the libsodium PHP extension is loaded, we'll use it above any other
     * solution.
     *
     * libsodium-php project:
     * @ref https://github.com/jedisct1/libsodium-php
     *
     * @param int $bytes
     *
     * @throws Exception
     *
     * @return string
     */
   
function random_bytes($bytes)
    {
        try {
           
$bytes = RandomCompat_intval($bytes);
        } catch (
TypeError $ex) {
            throw new
TypeError(
               
'random_bytes(): $bytes must be an integer'
           
);
        }

        if (
$bytes < 1) {
            throw new
Error(
               
'Length must be greater than 0'
           
);
        }

       
/**
         * \Sodium\randombytes_buf() doesn't allow more than 2147483647 bytes to be
         * generated in one invocation.
         */
       
if ($bytes > 2147483647) {
           
$buf = '';
            for (
$i = 0; $i < $bytes; $i += 1073741824) {
               
$n = ($bytes - $i) > 1073741824
                   
? 1073741824
                   
: $bytes - $i;
               
$buf .= \Sodium\randombytes_buf($n);
            }
        } else {
           
$buf = \Sodium\randombytes_buf($bytes);
        }

        if (
$buf !== false) {
            if (
RandomCompat_strlen($buf) === $bytes) {
                return
$buf;
            }
        }

       
/**
         * If we reach here, PHP has failed us.
         */
       
throw new Exception(
           
'Could not gather sufficient random data'
       
);
    }
}