Hautelook\Phpass\PasswordHash::get_random_bytes PHP Метод

    public function get_random_bytes($count)
    {
        $output = '';
        if (@is_readable('/dev/urandom') && ($fh = @fopen('/dev/urandom', 'rb'))) {
            $output = fread($fh, $count);
            fclose($fh);
        }
        if (strlen($output) < $count) {
            $output = '';
            for ($i = 0; $i < $count; $i += 16) {
                $this->random_state = md5(microtime() . $this->random_state);
                $output .= pack('H*', md5($this->random_state));
            }
            $output = substr($output, 0, $count);
        }
        return $output;
    }

 /**
  * Generate a cryptographically secure random string
  * @param int $length
  * @return string
  */
 public function getString($length = 12)
 {
     if (function_exists('random_bytes')) {
         $bytes = random_bytes($length / 2);
     } else {
         $hash = new PasswordHash(8, false);
         $bytes = $hash->get_random_bytes($length / 2);
     }
     return bin2hex($bytes);
 }