WebSocket connection to 'wss://' Error during WebSocket handshake: Unexpected response code: 400

Question

I use socket.io in my node.js app that's running on express.

Everything words fine on the local version (localhost) however when I switch to my production server (which is served via https using a custom certificate), I get the following error in my browser console:

websocket.js:112 WebSocket connection to 'wss://infranodus.com/socket.io/?EIO=3&transport=websocket&sid=j_WBxkPY_RlpF9_ZAANP' failed: Error during WebSocket handshake: Unexpected response code: 400

I made a research (issue referenced here) and it turns out this happens because my app / hosting provider blocks connections like wss and my socket.io falls back on AJAX to make requests (which functions OK, but sometimes there are bugs).

So I wanted to ask you if I could do modifications to my app to get rid of this error?

Just FYI currently all requests to http://infranodus.com are forwarded (via static .htaccess) to https://infranodus.com and my app.js file (the part of the server activation looks like that):

var http = require('http');

var app = express();

var server = http.Server(app);
var io = require('socket.io')(server);

app.set('port', process.env.PORT || 3000);
app.set('views', __dirname + '/views');
app.set('view engine', 'ejs');

and the way I require sockets in my front-end file:

<script src="/socket.io/socket.io.js"></script>

and then

var socket = io();

Maybe the problem is that I activate server in my node.js app using http and not https? But I would not like to switch to that because I don't know where my certificates are stored and I would not like to change the backend code too much.

UPDATE (21/10/2018): We figured out the problem is with nginx server and due to the limitations of some hosting providers who do not allow users to edit nginx servers, websockets over secure protocol get blocked or get 400 error. It would be nice to resolve this in sockets.io as it's a problem that many users have. Any ideas?

TO REPRODUCE THE ISSUE: Please, go open your Javascript Console and go to https://infranodus.com/news/english

SOURCE CODE: https://github.com/noduslabs/infranodus

Where are you hosting your app?, Do you have multiple servers, or just one? — Marcos Casagrande, Mar 30 '18 at 14:36
@MarcosCasagrande I only have one server and I'm hosting it on Webfaction — Aerodynamika, Mar 30 '18 at 15:01
If you are not sure, probably don't have control over it, and you won't be able to change anything. https://stackoverflow.com/questions/29043879/socket-io-with-nginx — Marcos Casagrande, Mar 30 '18 at 15:54
Which provider do you use for hosting? Have you confirmed with them that they do block websockets? When you say I use a custom certificate, does it mean a self-signed certificate or an actual certificate your purchases from a recognized provider? — Tarun Lalwani, Apr 02 '18 at 14:53
@TarunLalwani i use ComodoSSL certificate. The hosting provider is WebFaction and say they have everything opened. — Aerodynamika, Apr 02 '18 at 18:58
Can you post your `.htaccess`? and I assume the Certificate is automatically configure at WebFaction? — Tarun Lalwani, Apr 02 '18 at 22:26
@TarunLalwani I don't have any .htaccess — all the code I have in my root is available on https://github.com/noduslabs/infranodus — Aerodynamika, Apr 03 '18 at 07:07
@TarunLalwani and yes, the certificate is added through WebFaction control panel. — Aerodynamika, Apr 03 '18 at 07:07
Have you checked if firewall settings particular to your server allows connection through the web socket port? — oldink, Apr 04 '18 at 06:48

score 6 · Answer 1 · edited Jan 30 '21 at 02:09

6

I solved it with this:

var socket = io.connect("http://localhost:3000", {
   forceNew: true,
   transports: ["polling"],
});

edited Jan 30 '21 at 02:09

Maxdola

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answered Jan 08 '21 at 15:33

Paris López

57
1
1

Thank you, mate. I solved the issue with this solution. – Blockchain Pod Lead Oct 17 '21 at 23:41
Yep, this worked like a charm. Thank you – Lucas Rahn Dec 29 '21 at 19:31

score 4 · Answer 2 · answered Aug 07 '18 at 18:58

4

Check if you using express-status-monitor as a middleware on express, this makes http call on the first (request) handshake of WebSocket goes failed, if not maybe another factor like proxy (nginx) or similar like that

Look here More details about this error

answered Aug 07 '18 at 18:58

Aditya Kresna Permana

11,869
8
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Oh yes, I was all over that page, but no help there. And yes, it's a nginx issue and if I had access to my nginx server I could sort this out but how to resolve it when I don't have access? I develop this code so people can also install it on other servers and not all servers have the capacity to go to that level of config, so what to do? – Aerodynamika Oct 21 '18 at 21:53
When I face this problem try to break down every middleware attached into express, then do checking if the handshake issue was resolved by dropping them one by one. At the first place you should check that your application is not the issue. – Aditya Kresna Permana Oct 24 '18 at 03:47

score 2 · Answer 3 · answered Apr 05 '18 at 09:34

Use a secure URL for your initial connection, i.e. instead of "http://" use "https://". If the WebSocket transport is chosen, then Socket.IO should automatically use "wss://" (SSL) for the WebSocket connection too.

If you are not specifying any URL when you call io(), since it defaults trying to connect to the host that serves the page, either you have to provide url or change to https

  var socket = io.connect('https://localhost', {secure: true}); //remote url

score 2 · Answer 4 · answered Nov 05 '18 at 23:44

I had the same error.

I decided to visit infranodus.com/socket.io/?EIO=3&transport=websocket&sid=j_WBxkPY_RlpF9_ZAANP which returns the message "Session ID unknown".

Did you use multiple nodes ? If this is the case, please refer to the site https://socket.io/docs/using-multiple-nodes/.

As it says on the official site,

If you plan to distribute the load of connections among different processes or machines, you have to make sure that requests associated with a particular session id connect to the process that originated them.

This is due to certain transports like XHR Polling or JSONP Polling relying on firing several requests during the lifetime of the “socket”. Failing to enable sticky balancing will result in the dreaded:

Error during WebSocket handshake: Unexpected response code: 400

Reconfigure the Nginx config as explain then try to adapt the Express like this

let port = parseInt(your_port) + parseInt(process.env.NODE_APP_INSTANCE);
server.listen(port, console.log("Server running "+port));

Let us know if it changes something :)

Hey no I don't use multiple nodes. I think in my particular case the problem is the nginx server in between which i cannot configure because WebFaction hosting does not allow this... It would be nice to find a workaround though... — Aerodynamika, Nov 21 '18 at 16:31
Thank you, it was my case, — I was needed to modify Nginx configuration, because Nginx was preventing connections to be established. — AntonAL, Sep 15 '19 at 13:07

Manjunath Bilwar · Answer 5 · 2018-10-09T20:03:42.553

0

Try this two method if this work for you

Try this method 1:

I was facing the same issue. After 30 min debug I resolved the issue by enabling ALB (Application Load Balancer) Stickiness. It worked for me.

Try this method 2:

// Client side adding transport param:
var socket = io('http://localhost:3000', { transports: ['websocket'] });

You can set this value 'http://localhost:3000' as per your domain.

edited Oct 09 '18 at 20:03

answered Sep 12 '18 at 23:36

Manjunath Bilwar

2,215
19
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How to enable that? – Aerodynamika Sep 13 '18 at 00:03
Go to Load Balancer > Select Target Group > and down below there is a button to edit > Edit the button and enable the Stickiness. – Manjunath Bilwar Sep 16 '18 at 13:57
You're probably on Amazon, but my server is on WebFaction. Also, I tried the settings you provided, but that didn't do anything... – Aerodynamika Oct 21 '18 at 21:54
Yes, I am using the Amazon and it is working fine. Try some troubleshoot – Manjunath Bilwar Oct 22 '18 at 10:31

score 0 · Answer 6 · answered Jan 28 '21 at 17:58

I got this problem when I updated packages on the backend, python socketio, but didn't do it on the frontend.

But when I updated the packages everywhere, the problem was fixed. This was a problem in versions

I found this error in the browser after navigating to the link when the 400 error returned "The client is using an unsupported version of the Socket.IO or Engine.IO protocols"

WebSocket connection to 'wss://' Error during WebSocket handshake: Unexpected response code: 400

6 Answers6