В справочнике API, есть пример , описывающий проверку веб-крюка на разных языках, включая node.js.
Если вы хотите использовать express.js, вы можете начать с этого кода шаблона:
const express = require('express');
const crypto = require('crypto');
// Create a new instance of express
const app = express();
// Set up a raw bodyparser to read the webhook post
const bodyParserRaw = require('body-parser').raw({
type: '*/*',
});
function webhookValidator (req, res, next) {
// get the header signature from the webhook request
const givenSignature = req.headers['x-kc-signature'];
// throw error if it's missing
if (!givenSignature) {
console.log('Missing signature');
return res.status(409).json({
error: 'Missing signature'
});
}
// create HMAC from the raw request body
let hmac = crypto.createHmac('sha256', [your-webhook-secret-key]);
hmac.write(req.body);
hmac.end();
// get a base64 hash from HMAC
let hash = hmac.read().toString('base64');
// check validity with timingSafeEqual
let webhookValid = false;
try {
webhookValid = crypto.timingSafeEqual(Buffer.from(givenSignature, 'base64'), Buffer.from(hash, 'base64'));
} catch (e) {
webhookValid = false
}
// return validity
if (webhookValid) {
return next();
} else {
console.log('Invalid signature');
return res.status(409).json({
error: 'Invalid signature'
});
}
}
// create a route and pass through the bodyparser and validator
app.post('/webhook', bodyParserRaw, webhookValidator, ( req, res, next ) => {
// If execution gets here, the HMAC is valid
console.log('webhook is valid');
});