Intercom webhook signature validation

index.js

const express = require('express');
const bodyParser = require('body-parser');
const crypto = require('crypto');
const serverless = require('serverless-http');
const app = express();

const KEY = 'YOUR_KEY';

app.use(bodyParser.raw({
    type: '*/*',
}));

app.post('/webhooks/intercom', (req, res) => {
    const signature = req.headers['x-hub-signature'];

    console.log(req.body);

    const hmac = crypto.createHmac('sha1', KEY);
    hmac.update(req.body, 'utf-8');
    const signed = `sha1=${hmac.digest('hex')}`;

    console.log(signed);
    console.log(signature);

    if (signed === signature) {
        console.log('signatures match');
        res.sendStatus(200);
    } else {
        console.error('signatures DO NOT match');
        res.sendStatus(403);
    }
});

module.exports.handler = serverless(app);