iot.js

// iot side
// don't forget to install the following modules
const createKeccakHash = require('keccak')
var net = require('net');
const LoginContract = require('./login_contract.js');
var Web3 = require('web3');
var web3 = new Web3();

var HOST = '<IOT ip address>';
var event_happened = false;
var PORT = 9090;
var message;
var cnt = 0;
var token;
var address;
var publickey = new Buffer(1)

// wait for event
web3.setProvider(new web3.providers.HttpProvider('http://127.0.0.1:7545'));
const loginContract = LoginContract.at(process.env.LOGIN_CONTRACT_ADDRESS || '<smart contract eth address>');
const loginAttempt = loginContract.LoginAttempt();

loginAttempt.watch((error, event) => {
	if (error) {
		console.log(error);
		return;
	}
	event_happened = true;
	address = event.args.sender.toLowerCase();
	token = event.args.token;
	console.log("\x1b[42m", "[+] Authentication Event Arrived")
	console.log("\x1b[0m", "\n");
	console.log("Sender Address: " + address);
	console.log("Authentication Token: " + token);
});

// listen to input
net.createServer(function (sock) {
	console.log('CONNECTED Client: ' + sock.remoteAddress + ':' + sock.remotePort);
	sock.on('data', function (data) {
		if (cnt == 0) {
			message = data.toString();
			cnt++;
		}
		if (cnt == 1) {
			publickey = data;
			cnt++;
		}
		if (cnt == 2) {
			sign = data.toString();
			cnt++;
		}
		var resM = message.split(",")
		if (cnt === 3 && resM[0] === token && resM[1] == sock.remoteAddress.toString()) {
			createKeccakHash('keccak256').digest().toString('hex');
			var add = createKeccakHash('keccak256').update(publickey).digest('hex');
			if (address.toString().trim() === address) {
				console.log("\x1b[42m", "[+] User Validated .. Access Granted");
				console.log("\x1b[0m", "\n");
				cnt = 0;
				sock.write('All Good');
			}
		}
		else { sock.write('!'); }
	});

	// Add a 'close' event handler to this instance of socket
	sock.on('close', function (data) {
		console.log('CLOSED: ' + sock.remoteAddress + ' ' + sock.remotePort);
	});
}).listen(PORT, HOST);
console.log('Device listening on ' + HOST + ':' + PORT);