PHP가 효율적인 온라인 결제 기능을 구현하고 안전하고 안정적인 결제 서비스를 제공하는 방법

class Alipay {

    private $app_id; // 应用ID
    private $merchant_private_key; // 商户私钥
    private $alipay_public_key; // 支付宝公钥

    public function __construct($app_id, $merchant_private_key, $alipay_public_key) {
        $this->app_id = $app_id;
        $this->merchant_private_key = $merchant_private_key;
        $this->alipay_public_key = $alipay_public_key;
    }

    // 发起支付宝即时到账接口请求
    public function trade($out_trade_no, $total_amount, $subject) {
        $data = array(
            'app_id' => $this->app_id,
            'method' => 'alipay.trade.page.pay',
            'charset' => 'utf-8',
            'timestamp' => date('Y-m-d H:i:s'),
            'version' => '1.0',
            'biz_content' => json_encode(array(
                'out_trade_no' => $out_trade_no,
                'total_amount' => $total_amount,
                'subject' => $subject,
                'product_code' => 'FAST_INSTANT_TRADE_PAY'
            )),
            'sign_type' => 'RSA2'
        );
        $sign = $this->sign($data);
        $data['sign'] = $sign;
        $url = 'https://openapi.alipay.com/gateway.do?' . http_build_query($data);
        header('Location: ' . $url);
        exit();
    }

    // 生成签名
    private function sign($data) {
        ksort($data);
        $str = '';
        foreach ($data as $key => $value) {
            if ($key != 'sign' && $value != '') {
                $str .= $key . '=' . $value . '&';
            }
        }
        $str = substr($str, 0, -1);
        $sign = '';
        openssl_sign($str, $sign, $this->merchant_private_key, OPENSSL_ALGO_SHA256);
        $sign = base64_encode($sign);
        return $sign;
    }

}

class Alipay {

    // 验证通知签名
    public function verifySign($data) {
        $sign = $data['sign'];
        unset($data['sign']);
        $raw = urldecode(http_build_query($data));
        $result = openssl_verify($raw, base64_decode($sign), $this->alipay_public_key, OPENSSL_ALGO_SHA256);
        return $result == 1;
    }

    // 接收支付宝异步通知
    public function receiveNotify($callback) {
        $data = $_POST;
        if (!$this->verifySign($data)) {
            return false;
        }
        $result = call_user_func($callback, $data);
        if ($result) {
            echo 'success';
        } else {
            echo 'failure';
        }
        exit();
    }

}