I've been working with Socket.IO for a few days and it's been both extremely exciting and even more frustrating. The lack of current documentation/tutorials has made learning it very difficult. I finally managed to create a basic chat system, but there is one glaring question. How do I secure it?
What's stopping a malicious user from copying (or editing) my code and connecting to my server? I can grab the username from my PHP script and submit it to Socket.IO so I can recognize them as that user (and the PHP has security of course), but what's stopping someone from just submitting an unregistered username?
How can I make sure that the events submitted are authentic and haven't been tampered with?
My basic socket.io chat for references.
Server:
var io = require('socket.io').listen(8080);
var connectCounter = 0;
io.sockets.on('connection', function (socket) {
connectCounter++;
console.log('People online: ', connectCounter);
socket.on('set username', function(username) {
socket.set('username', username, function() {
console.log('Connect', username);
});
});
socket.on('emit_msg', function (msg) {
// Get the variable 'username'
socket.get('username', function (err, username) {
console.log('Chat message by', username);
io.sockets.volatile.emit( 'broadcast_msg' , username + ': ' + msg );
});
});
socket.on('disconnect', function() { connectCounter--; });
});
Client:
<?php session_start() ?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<title>untitled</title>
</head>
<body>
<input id='message' type='text'>
<div id="content"></div>
<script src="http://localhost:8080/socket.io/socket.io.js"></script>
<script src="http://code.jquery.com/jquery-latest.js"></script>
<script>
var socket = io.connect('http://localhost:8080');
$.ajax({
type: 'GET',
url: 'https://mysite.com/execs/login.php?login_check=true',
dataType: 'json',
success: function(data) {
var username = data.username;
socket.emit('set username', username, function (data){
});
}
});
socket.on('broadcast_msg', function (data) {
console.log('Get broadcasted msg:', data);
var msg = '<li>' + data + '</li>';
$('#content').append(msg);
});
$('#message').keydown(function(e) {
if(e.keyCode == 13) {
e.stopPropagation();
var txt = $(this).val();
$(this).val('');
socket.emit('emit_msg', txt, function (data){
console.log('Emit Broadcast msg', data);
});
}
});
</script>
</body>
</html>
It all works dandy, except for having absolutely no security.