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@bradwright
Created June 11, 2011 23:29
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Pure Node.js WebSockets server
/*
* node-ws - pure Javascript WebSockets server
* Copyright Bradley Wright <brad@intranation.com>
*/
// Use strict compilation rules - we're not animals
'use strict';
var net = require('net'),
crypto = require('crypto');
function bigEndian(value) {
var result = [
String.fromCharCode(value >> 24 & 0xFF),
String.fromCharCode(value >> 16 & 0xFF),
String.fromCharCode(value >> 8 & 0xFF),
String.fromCharCode(value & 0xFF)
];
return result.join('');
}
function computeKey(key) {
/*
* For each of these fields, the server has to
* take the digits from the value to obtain a
* number, then divide that number by the number
* of spaces characters in the value to obtain
* a 32-bit number.
*/
var length = parseInt(key.match(/\s/g).length),
chars = parseInt(key.replace(/[^0-9]/g, ''));
return (chars / length);
}
// protocol 00
// http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-00
function HandshakeHYBI00(request) {
// split up lines and parse
var lines = request.split('\r\n'),
headers = parseHeaders(lines);
if ('sec-websocket-key1' in headers &&
'sec-websocket-key2' in headers) {
var key1 = computeKey(headers['sec-websocket-key1']),
key2 = computeKey(headers['sec-websocket-key2']),
/*
* The third piece of information is given
* after the fields, in the last eight
* bytes of the handshake, expressed here
* as they would be seen if interpreted as ASCII
*/
data = request.slice(-8, request.length),
// md5 hhash
hash = crypto.createHash('md5');
// update hash with all values
hash.update(bigEndian(key1));
hash.update(bigEndian(key2));
hash.update(data);
// TODO: make this a template maybe
var response = [
'HTTP/1.1 101 WebSocket Protocol Handshake',
'Upgrade: WebSocket',
'Connection: Upgrade',
'Sec-WebSocket-Origin: ' + headers['origin'],
// TODO: ws or wss
// TODO: add actual request path
'Sec-WebSocket-Location: ws://' + headers['host'] + '/',
'',
hash.digest('binary')
];
return response;
}
return false;
}
function parseHeaders(headers) {
// splits a list of headers into key/value pairs
var parsedHeaders = {};
headers.forEach(function(header) {
// might contain a colon, so limit split
var toParse = header.split(':');
if (toParse.length >= 2) {
// it has to be Key: Value
var key = toParse[0].toLowerCase(),
// might be more than 1 colon
value = toParse.slice(1).join(':')
.replace(/^\s\s*/, '')
.replace(/\s\s*$/, '');
parsedHeaders[key] = value;
}
else {
// it might be a method request,
// which we want to store and check
if (header.indexOf('GET') === 0) {
parsedHeaders['X-Request-Method'] = 'GET';
}
}
});
return parsedHeaders;
}
var WebsocketServer = net.createServer(function (socket) {
// listen for connections
var wsConnected = false;
socket.addListener('data', function (data) {
// are we connected?
if (wsConnected) {
console.log(data.toString('utf8'));
}
else {
var response = HandshakeHYBI00(data.toString('binary'));
if (response) {
// handshake succeeded, open connection
socket.write(response.join('\r\n'), 'binary');
wsConnected = true;
}
else {
// close connection, handshake bad
socket.end();
return;
}
}
});
});
WebsocketServer.listen(8080, "127.0.0.1");
@regentking
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Take a star and a fork good sir.

@r3wt
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r3wt commented May 25, 2014

you sir are the shit.

@AnoyingShulkerMC
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AnoyingShulkerMC commented Dec 2, 2018

I have a problem. when I try:
var web = new WebSocket("ws://localhost:8080")
in the browser. I get this error
VM138:1 WebSocket connection to 'ws://localhost:8080/' failed: Connection closed before receiving a handshake response

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