NODE JS example of creating a HTTP Authentication: MAC Access Authentication with SHA-256

node-hmac-auth.js

/* NODE JS example of creating a HTTP Authentication: MAC Access Authentication with SHA-256
 * https://tools.ietf.org/html/draft-ietf-oauth-v2-http-mac-00
 */

const crypto = require('crypto');
const baseURL = 'https://example.com';
const serverId = 'SERVER-PROVIDED-ID';
const secretKey = 'SUPER-SECRET-BASE64-KEY';
const issuedKeyAt = 1557794619;
const randomString = 'WINTERBOOTS';

function createBase64Hash(data, hashAlg = 'sha256') {
	return crypto
		.createHash(hashAlg)
		.update(data)
		.digest('base64');
}

function createHMACBase64Hash(data, hashAlg = 'sha256') {
	return crypto
		.createHmac(hashAlg, Buffer.from(secretKey, 'base64'))
		.update(data)
		.digest('base64');
}

function getEpochSinceIssued() {
	const currentEpochDate = Math.floor(new Date().getTime() / 1000.0);
	return currentEpochDate - issuedKeyAt;
}

function createHMACAuth(domain, route, method, payload) {
	const hostname = domain.replace('https://', '');
	const secondsSinceIssued = getEpochSinceIssued();
	const bodyHash = createBase64Hash(JSON.stringify(payload));
	const nonce = `${secondsSinceIssued}:${randomString}`;

	const macString = `${nonce}\=${method}\n${route}\n${hostname}\n443\n${bodyHash}\n\n`;
	const mac = createHMACBase64Hash(macString);
	return `MAC id='${serverId}',nonce='${nonce}',bodyhash='${bodyHash}',mac='${mac}'`;
}

const newUser = {
	email: 'helloworld@example.com',
	password: 'H-MAC-KING',
};

const macAuth = createHMACAuth(baseURL, '/users', 'POST', newUser);
console.log({
	headers: {
		Authorization: macAuth,
	},
});