<?php 
/** 
 * Random_* Compatibility Library  
 * for using the new PHP 7 random_* API in PHP 5 projects 
 *  
 * The MIT License (MIT) 
 *  
 * Copyright (c) 2015 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 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' 
    ); 
} 
 
 |