Hello,

I use PHP 8.1.
When I call X509->loadCSR(), I get this error if some fields are not filled in:

explode(): Passing null to parameter #2 ($string) of type string is deprecated

Il solved this problem by adding this lines in X509 class:

private function &subArray(&$root, $path, $create = false)
{
        $false = false;
        if (!is_array($root)) {
            return $false;
        }

>       if (is_null($path)){
>           $path = '';
>       }

        ......
}