koa-ws-cookie-helper

koa.js + ws.js helper for accessing cookies from a WebSocket connection

Installation

$ npm install koa-ws-cookie-helper

Example

var koa = require('koa'),
    WebSocketServer = require('ws').Server,
    cookieHelper = require('koa-ws-cookie-helper'),
    app = koa();
 
var port = 3000;
app.keys = ['secret'];
 
app.server = app.listen(port);
 
var wss = new WebSocketServer({server: app.server});
wss.on('connection', function (client) {
 
  // first argument is of type WebSocket
  
  // tries to get value of cookie named 'foo'
  // e.g. for 'foo=bar', returns 'bar'
  var cookieValue = cookieHelper.get(client, 'foo', app.keys);
 
  // if you use unsigned cookies or 
  // don't care if the cookie is legit or not
  // omit the keys parameter
  cookieValue = cookieHelper.get(client, 'foo'); 
 
});

How does it work?

Browsers put any cookies from the same host into initial WebSocket handshake headers. This lets typical HTTP-session mechanisms to work with WebSockets. koa.js makes use of Cookies module to handle cookie management. Signed cookies are signed and verified using Keygrip. This module combines methods used by them to parse cookies in ws.upgradeReq.headers.cookie.

API

There is only a single public function:

get(ws, name, [keys])

Returns value of the cookie named name, using keyset keys. Cookie is searched in 'Cookie' entry of handshake headers. If no cookie could be found or if the signed cookie does not match with any key in the keyset, returns undefined.

License

MIT