socket.io-client how to set request header when making connection

Question

I'm trying to set a http header when socket.io client makes the connection request. Is there a way to do this?

Here is what i'm doing:

// server side
var io = socketio(server);

io.use(function (socket, next) {
  // authorize using authorization header in socket.request.headers
});

// client side
var socket = io();  // i'm trying to set an authorization header in this http reqeust

Any ideas? Thanks.

Answer 1

You can use extraHeaders option, if you are using socket.io-client >= 1.4.

For example:

var socket = io("http://localhost", {
  extraHeaders: {
    Authorization: "Bearer authorization_token_here"
  }
});

engine.io-client, which is a backend of socket.io-client, introduced extraHeaders support on 2015-11-28.

Answer 2

It seems like the client doesn't support setting headers, as not all transports allow for the setting of headers.

This post by facundoolano details a workaround to authentication that doesn't require placing the auth token in the query string.

His workaround module can be found at https://github.com/invisiblejs/socketio-auth.

Makes me wonder why on server-side, socket.io allows for the request headers to be accessed...

Answer 3

There's a new way to do this: https://socket.io/docs/v3/middlewares/. Look under the "Sending Credentials" section.

// client
const socket = io(server, {
    transports: ['websocket', 'polling', 'flashsocket'],
    auth: {
        token: 'abc'
    }
});

// server
io.use((socket, next) => {
    const token = socket.handshake.auth.token;
    if (isValidJwt(token)){
        next();
    }else{
        next(new Error("Socket authentication error"));
    }
});

async function isValidJwt(token){
    jwt.verify(token, secrets.jwt, function(err, decoded) {
        if (err){
            console.log(err);
            return false;
        }else{
            //console.log(decoded);
            return true;
        }
    });
}

Answer 4

This following information has been deprecated since socket.io 1.0

There are two methods of authorization: global or namespace (think route). The global method is set on the server with the io.set('authorization', function (handshakeData, callback) configuration call.

The handshakeData object contains the following information:

{
   headers: req.headers       // <Object> the headers of the request
 , time: (new Date) +''       // <String> date time of the connection
 , address: socket.address()  // <Object> remoteAddress and remotePort object
 , xdomain: !!headers.origin  // <Boolean> was it a cross domain request?
 , secure: socket.secure      // <Boolean> https connection
 , issued: +date              // <Number> EPOCH of when the handshake was created
 , url: request.url          // <String> the entrance path of the request
 , query: data.query          // <Object> the result of url.parse().query or a empty object
}

The above information and a deeper explanation is available on this documentation page.

Answer 5

As of version 2.0.0 / 2017-01-22 engine.io-client supports

[feature] Allow extraHeaders to be set for browser clients in XHR requests (#519)

However at this point the socket.io-client is not updated to support this functionality, so couple of days may make this saga end until that time use the following instructions: https://facundoolano.wordpress.com/2014/10/11/better-authentication-for-socket-io-no-query-strings/

Answer 6

"transportOptions" options can be used to send extra headers in socket.io request. I also explained that here :-

Node.js + Socket.io | Set custom headers on the server

Answer 7

Short Answer: It's imposiburu based on spec... if you just need to pass info early... why not query parameters?

socket = io('localhost:5000', {
      path: '/mySocketPath',
      transports: ['websocket'],
      query: {
        token:'some-token-value'
      }
})

See @satpal-07 in https://github.com/socketio/socket.io-client/issues/1356#issuecomment-810023635

Answer 8

For some reason, these request headers are only received if the socket server is also socket.io. If I connect to a python Websockets server for example I have no luck authenticating.

The only solution that worked for me is to use a different WebSocket client, for example, ws works fine.

import WebSocket from 'ws';

const socket = new WebSocket('wss://example.com/path', {
      headers: {
            Authorization: 'token'
         },
 });