Tuupola's Basic Authenticator & Error Messages

1

How would you pass back a custom error code or message from a custom authenticator using Tuupolas Basic Authenticator? Obviously my example below is pulled completely out of thin air and would never work, but I think you get what I mean? Somehow, there must be a way to pass a message from here, back to the error handler, or alter the $arguments? Any tips?

class DbAuthenticator implements AuthenticatorInterface {
     public function __invoke(array $arguments) {
        if (wrongPassword($user, $pass)) {
            ==> $returnThisMessageSomeHow = "Invalid password";
            $failedLogins = $failedLogins + 1;
            return false;
        } 
        if (invalidUsername($user, $pass)) {
            ==> $returnAmessageSomeHow = "Invalid username";
            return false;
        }
    }
}

then…

$container["HttpBasicAuthentication"] = function ($container) {
    return new HttpBasicAuthentication([
        "path" => [ ... ],
        "authenticator" => new DbAuthenticator(),
        "error" => function ($request, $response, $arguments) {
            $data = [];
            $data["status"] = "error";
            ==> $data["message"] = $messageReturnedFromAuthenticatorSomehow;
            return $response->write(json_encode($data, JSON_UNESCAPED_SLASHES));
        }
    ]);
};