Integrating Secure Payment Gateways for Ecommerce

1. Payment Gateway Tokenization & PCI Compliance

Handling unencrypted primary account numbers (PAN) directly on your origin server puts your business in PCI SAQ D scope. Tokenization replaces sensitive card numbers with encrypted tokens returned by processor iframe fields.

2. Node.js Stripe Webhook Signature Verification

// Express Webhook Handler verifying Stripe HMAC Signature
const express = require('express');
const stripe = require('stripe')(process.env.STRIPE_SECRET_KEY);
const app = express();

app.post('/webhooks/stripe', express.raw({ type: 'application/json' }), (req, res) => {
  const sig = req.headers['stripe-signature'];
  let event;

  try {
    event = stripe.webhooks.constructEvent(req.body, sig, process.env.STRIPE_WEBHOOK_SECRET);
  } catch (err) {
    return res.status(400).send(`Webhook Signature Verification Error: ${err.message}`);
  }

  if (event.type === 'payment_intent.succeeded') {
    const paymentIntent = event.data.object;
    fulfillOrder(paymentIntent.metadata.orderId);
  }

  res.json({ received: true });
});

3. Frequently Asked Questions (FAQ)

1. Why are hosted iframe fields mandatory?

Hosted iframes isolate sensitive credit card inputs from the merchant's DOM, securing PCI SAQ A compliance.

2. How does 3D Secure 2.0 reduce chargebacks?

3DS2 uses biometric authentication and data sharing between the merchant and issuing bank to shift chargeback liability to card issuers.