private static function getRandomBytes($count)
{
$bytes = '';
if (function_exists('openssl_random_pseudo_bytes') && strtoupper(substr(PHP_OS, 0, 3)) !== 'WIN') {
// OpenSSL slow on Win
$bytes = openssl_random_pseudo_bytes($count);
}
if ($bytes === '' && is_readable('/dev/urandom') && ($hRand = @fopen('/dev/urandom', 'rb')) !== FALSE) {
$bytes = fread($hRand, $count);
fclose($hRand);
}
if (strlen($bytes) < $count) {
$bytes = '';
if (self::$randomState === null) {
self::$randomState = microtime();
if (function_exists('getmypid')) {
self::$randomState .= getmypid();
}
}
for ($i = 0; $i < $count; $i += 16) {
self::$randomState = md5(microtime() . self::$randomState);
if (PHP_VERSION >= '5') {
$bytes .= md5(self::$randomState, true);
} else {
$bytes .= pack('H*', md5(self::$randomState));
}
}
$bytes = substr($bytes, 0, $count);
}
return $bytes;
}
