protected function initPinsFromENV()
    {
        if (($userData = getenv('PINENTRY_USER_DATA')) !== false) {
            $pins = json_decode($userData, true);
            if ($pins === null) {
                $this->log(
                    '-- failed to parse user data' . PHP_EOL,
                    self::VERBOSITY_ERRORS
                );
            } else {
                $this->pins = $pins;
                $this->log(
                    '-- got user data [not showing passphrases]' . PHP_EOL,
                    self::VERBOSITY_ALL
                );
            }
        }

        return $this;
    }