mytharcher\sdk\alipay\Alipay::buildSignedParameters PHP Method

    function buildSignedParameters($params)
    {
        $params = $this->prepareParameters($params);
        $params['sign'] = $this->signParameters($params);
        if ($params['service'] != self::SERVICE_WAP && $params['service'] != self::SERVICE_WAP_AUTH) {
            $params['sign_type'] = strtoupper(trim($this->config['sign_type']));
        }
        return $params;
    }