<?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'
);
}
}