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shrine-medco/shrine-webclient/src/main/html/node_modules/ws/lib/WebSocketServer.js
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WebSocketServer.js
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			/*!
			* ws: a node.js websocket client
			* Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
			* MIT Licensed
			*/

			var util = require('util')
			, events = require('events')
			, http = require('http')
			, crypto = require('crypto')
			, Options = require('options')
			, WebSocket = require('./WebSocket')
			, Extensions = require('./Extensions')
			, PerMessageDeflate = require('./PerMessageDeflate')
			, tls = require('tls')
			, url = require('url');

			/**
			* WebSocket Server implementation
			*/

			function WebSocketServer(options, callback) {
			if (this instanceof WebSocketServer === false) {
			return new WebSocketServer(options, callback);
			}

			events.EventEmitter.call(this);

			options = new Options({
			host: '0.0.0.0',
			port: null,
			server: null,
			verifyClient: null,
			handleProtocols: null,
			path: null,
			noServer: false,
			disableHixie: false,
			clientTracking: true,
			perMessageDeflate: true,
			maxPayload: null
			}).merge(options);

			if (!options.isDefinedAndNonNull('port') && !options.isDefinedAndNonNull('server') && !options.value.noServer) {
			throw new TypeError('`port` or a `server` must be provided');
			}

			var self = this;

			if (options.isDefinedAndNonNull('port')) {
			this._server = http.createServer(function (req, res) {
			var body = http.STATUS_CODES[426];
			res.writeHead(426, {
			'Content-Length': body.length,
			'Content-Type': 'text/plain'
			});
			res.end(body);
			});
			this._server.allowHalfOpen = false;
			this._server.listen(options.value.port, options.value.host, callback);
			this._closeServer = function() { if (self._server) self._server.close(); };
			}
			else if (options.value.server) {
			this._server = options.value.server;
			if (options.value.path) {
			// take note of the path, to avoid collisions when multiple websocket servers are
			// listening on the same http server
			if (this._server._webSocketPaths && options.value.server._webSocketPaths[options.value.path]) {
			throw new Error('two instances of WebSocketServer cannot listen on the same http server path');
			}
			if (typeof this._server._webSocketPaths !== 'object') {
			this._server._webSocketPaths = {};
			}
			this._server._webSocketPaths[options.value.path] = 1;
			}
			}
			if (this._server) {
			this._onceServerListening = function() { self.emit('listening'); };
			this._server.once('listening', this._onceServerListening);
			}

			if (typeof this._server != 'undefined') {
			this._onServerError = function(error) { self.emit('error', error) };
			this._server.on('error', this._onServerError);
			this._onServerUpgrade = function(req, socket, upgradeHead) {
			//copy upgradeHead to avoid retention of large slab buffers used in node core
			var head = new Buffer(upgradeHead.length);
			upgradeHead.copy(head);

			self.handleUpgrade(req, socket, head, function(client) {
			self.emit('connection'+req.url, client);
			self.emit('connection', client);
			});
			};
			this._server.on('upgrade', this._onServerUpgrade);
			}

			this.options = options.value;
			this.path = options.value.path;
			this.clients = [];
			}

			/**
			* Inherits from EventEmitter.
			*/

			util.inherits(WebSocketServer, events.EventEmitter);

			/**
			* Immediately shuts down the connection.
			*
			* @api public
			*/

			WebSocketServer.prototype.close = function(callback) {
			// terminate all associated clients
			var error = null;
			try {
			for (var i = 0, l = this.clients.length; i < l; ++i) {
			this.clients[i].terminate();
			}
			}
			catch (e) {
			error = e;
			}

			// remove path descriptor, if any
			if (this.path && this._server._webSocketPaths) {
			delete this._server._webSocketPaths[this.path];
			if (Object.keys(this._server._webSocketPaths).length == 0) {
			delete this._server._webSocketPaths;
			}
			}

			// close the http server if it was internally created
			try {
			if (typeof this._closeServer !== 'undefined') {
			this._closeServer();
			}
			}
			finally {
			if (this._server) {
			this._server.removeListener('listening', this._onceServerListening);
			this._server.removeListener('error', this._onServerError);
			this._server.removeListener('upgrade', this._onServerUpgrade);
			}
			delete this._server;
			}
			if(callback)
			callback(error);
			else if(error)
			throw error;
			}

			/**
			* Handle a HTTP Upgrade request.
			*
			* @api public
			*/

			WebSocketServer.prototype.handleUpgrade = function(req, socket, upgradeHead, cb) {
			// check for wrong path
			if (this.options.path) {
			var u = url.parse(req.url);
			if (u && u.pathname !== this.options.path) return;
			}

			if (typeof req.headers.upgrade === 'undefined' \|\| req.headers.upgrade.toLowerCase() !== 'websocket') {
			abortConnection(socket, 400, 'Bad Request');
			return;
			}

			if (req.headers['sec-websocket-key1']) handleHixieUpgrade.apply(this, arguments);
			else handleHybiUpgrade.apply(this, arguments);
			}

			module.exports = WebSocketServer;

			/**
			* Entirely private apis,
			* which may or may not be bound to a sepcific WebSocket instance.
			*/

			function handleHybiUpgrade(req, socket, upgradeHead, cb) {
			// handle premature socket errors
			var errorHandler = function() {
			try { socket.destroy(); } catch (e) {}
			}
			socket.on('error', errorHandler);

			// verify key presence
			if (!req.headers['sec-websocket-key']) {
			abortConnection(socket, 400, 'Bad Request');
			return;
			}

			// verify version
			var version = parseInt(req.headers['sec-websocket-version']);
			if ([8, 13].indexOf(version) === -1) {
			abortConnection(socket, 400, 'Bad Request');
			return;
			}

			// verify protocol
			var protocols = req.headers['sec-websocket-protocol'];

			// verify client
			var origin = version < 13 ?
			req.headers['sec-websocket-origin'] :
			req.headers['origin'];

			// handle extensions offer
			var extensionsOffer = Extensions.parse(req.headers['sec-websocket-extensions']);

			// handler to call when the connection sequence completes
			var self = this;
			var completeHybiUpgrade2 = function(protocol) {

			// calc key
			var key = req.headers['sec-websocket-key'];
			var shasum = crypto.createHash('sha1');
			shasum.update(key + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11");
			key = shasum.digest('base64');

			var headers = [
			'HTTP/1.1 101 Switching Protocols'
			, 'Upgrade: websocket'
			, 'Connection: Upgrade'
			, 'Sec-WebSocket-Accept: ' + key
			];

			if (typeof protocol != 'undefined') {
			headers.push('Sec-WebSocket-Protocol: ' + protocol);
			}

			var extensions = {};
			try {
			extensions = acceptExtensions.call(self, extensionsOffer);
			} catch (err) {
			abortConnection(socket, 400, 'Bad Request');
			return;
			}

			if (Object.keys(extensions).length) {
			var serverExtensions = {};
			Object.keys(extensions).forEach(function(token) {
			serverExtensions[token] = [extensions[token].params]
			});
			headers.push('Sec-WebSocket-Extensions: ' + Extensions.format(serverExtensions));
			}

			// allows external modification/inspection of handshake headers
			self.emit('headers', headers);

			socket.setTimeout(0);
			socket.setNoDelay(true);
			try {
			socket.write(headers.concat('', '').join('\r\n'));
			}
			catch (e) {
			// if the upgrade write fails, shut the connection down hard
			try { socket.destroy(); } catch (e) {}
			return;
			}

			var client = new WebSocket([req, socket, upgradeHead], {
			protocolVersion: version,
			protocol: protocol,
			extensions: extensions,
			maxPayload: self.options.maxPayload
			});

			if (self.options.clientTracking) {
			self.clients.push(client);
			client.on('close', function() {
			var index = self.clients.indexOf(client);
			if (index != -1) {
			self.clients.splice(index, 1);
			}
			});
			}

			// signal upgrade complete
			socket.removeListener('error', errorHandler);
			cb(client);
			}

			// optionally call external protocol selection handler before
			// calling completeHybiUpgrade2
			var completeHybiUpgrade1 = function() {
			// choose from the sub-protocols
			if (typeof self.options.handleProtocols == 'function') {
			var protList = (protocols \|\| "").split(/, */);
			var callbackCalled = false;
			var res = self.options.handleProtocols(protList, function(result, protocol) {
			callbackCalled = true;
			if (!result) abortConnection(socket, 401, 'Unauthorized');
			else completeHybiUpgrade2(protocol);
			});
			if (!callbackCalled) {
			// the handleProtocols handler never called our callback
			abortConnection(socket, 501, 'Could not process protocols');
			}
			return;
			} else {
			if (typeof protocols !== 'undefined') {
			completeHybiUpgrade2(protocols.split(/, */)[0]);
			}
			else {
			completeHybiUpgrade2();
			}
			}
			}

			// optionally call external client verification handler
			if (typeof this.options.verifyClient == 'function') {
			var info = {
			origin: origin,
			secure: typeof req.connection.authorized !== 'undefined' \|\| typeof req.connection.encrypted !== 'undefined',
			req: req
			};
			if (this.options.verifyClient.length == 2) {
			this.options.verifyClient(info, function(result, code, name) {
			if (typeof code === 'undefined') code = 401;
			if (typeof name === 'undefined') name = http.STATUS_CODES[code];

			if (!result) abortConnection(socket, code, name);
			else completeHybiUpgrade1();
			});
			return;
			}
			else if (!this.options.verifyClient(info)) {
			abortConnection(socket, 401, 'Unauthorized');
			return;
			}
			}

			completeHybiUpgrade1();
			}

			function handleHixieUpgrade(req, socket, upgradeHead, cb) {
			// handle premature socket errors
			var errorHandler = function() {
			try { socket.destroy(); } catch (e) {}
			}
			socket.on('error', errorHandler);

			// bail if options prevent hixie
			if (this.options.disableHixie) {
			abortConnection(socket, 401, 'Hixie support disabled');
			return;
			}

			// verify key presence
			if (!req.headers['sec-websocket-key2']) {
			abortConnection(socket, 400, 'Bad Request');
			return;
			}

			var origin = req.headers['origin']
			, self = this;

			// setup handshake completion to run after client has been verified
			var onClientVerified = function() {
			var wshost;
			if (!req.headers['x-forwarded-host'])
			wshost = req.headers.host;
			else
			wshost = req.headers['x-forwarded-host'];
			var location = ((req.headers['x-forwarded-proto'] === 'https' \|\| socket.encrypted) ? 'wss' : 'ws') + '://' + wshost + req.url
			, protocol = req.headers['sec-websocket-protocol'];

			// build the response header and return a Buffer
			var buildResponseHeader = function() {
			var headers = [
			'HTTP/1.1 101 Switching Protocols'
			, 'Upgrade: WebSocket'
			, 'Connection: Upgrade'
			, 'Sec-WebSocket-Location: ' + location
			];
			if (typeof protocol != 'undefined') headers.push('Sec-WebSocket-Protocol: ' + protocol);
			if (typeof origin != 'undefined') headers.push('Sec-WebSocket-Origin: ' + origin);

			return new Buffer(headers.concat('', '').join('\r\n'));
			};

			// send handshake response before receiving the nonce
			var handshakeResponse = function() {

			socket.setTimeout(0);
			socket.setNoDelay(true);

			var headerBuffer = buildResponseHeader();

			try {
			socket.write(headerBuffer, 'binary', function(err) {
			// remove listener if there was an error
			if (err) socket.removeListener('data', handler);
			return;
			});
			} catch (e) {
			try { socket.destroy(); } catch (e) {}
			return;
			};
			};

			// handshake completion code to run once nonce has been successfully retrieved
			var completeHandshake = function(nonce, rest, headerBuffer) {
			// calculate key
			var k1 = req.headers['sec-websocket-key1']
			, k2 = req.headers['sec-websocket-key2']
			, md5 = crypto.createHash('md5');

			[k1, k2].forEach(function (k) {
			var n = parseInt(k.replace(/[^\d]/g, ''))
			, spaces = k.replace(/[^ ]/g, '').length;
			if (spaces === 0 \|\| n % spaces !== 0){
			abortConnection(socket, 400, 'Bad Request');
			return;
			}
			n /= spaces;
			md5.update(String.fromCharCode(
			n >> 24 & 0xFF,
			n >> 16 & 0xFF,
			n >> 8 & 0xFF,
			n & 0xFF));
			});
			md5.update(nonce.toString('binary'));

			socket.setTimeout(0);
			socket.setNoDelay(true);

			try {
			var hashBuffer = new Buffer(md5.digest('binary'), 'binary');
			var handshakeBuffer = new Buffer(headerBuffer.length + hashBuffer.length);
			headerBuffer.copy(handshakeBuffer, 0);
			hashBuffer.copy(handshakeBuffer, headerBuffer.length);

			// do a single write, which - upon success - causes a new client websocket to be setup
			socket.write(handshakeBuffer, 'binary', function(err) {
			if (err) return; // do not create client if an error happens
			var client = new WebSocket([req, socket, rest], {
			protocolVersion: 'hixie-76',
			protocol: protocol
			});
			if (self.options.clientTracking) {
			self.clients.push(client);
			client.on('close', function() {
			var index = self.clients.indexOf(client);
			if (index != -1) {
			self.clients.splice(index, 1);
			}
			});
			}

			// signal upgrade complete
			socket.removeListener('error', errorHandler);
			cb(client);
			});
			}
			catch (e) {
			try { socket.destroy(); } catch (e) {}
			return;
			}
			}

			// retrieve nonce
			var nonceLength = 8;
			if (upgradeHead && upgradeHead.length >= nonceLength) {
			var nonce = upgradeHead.slice(0, nonceLength);
			var rest = upgradeHead.length > nonceLength ? upgradeHead.slice(nonceLength) : null;
			completeHandshake.call(self, nonce, rest, buildResponseHeader());
			}
			else {
			// nonce not present in upgradeHead
			var nonce = new Buffer(nonceLength);
			upgradeHead.copy(nonce, 0);
			var received = upgradeHead.length;
			var rest = null;
			var handler = function (data) {
			var toRead = Math.min(data.length, nonceLength - received);
			if (toRead === 0) return;
			data.copy(nonce, received, 0, toRead);
			received += toRead;
			if (received == nonceLength) {
			socket.removeListener('data', handler);
			if (toRead < data.length) rest = data.slice(toRead);

			// complete the handshake but send empty buffer for headers since they have already been sent
			completeHandshake.call(self, nonce, rest, new Buffer(0));
			}
			}

			// handle additional data as we receive it
			socket.on('data', handler);

			// send header response before we have the nonce to fix haproxy buffering
			handshakeResponse();
			}
			}

			// verify client
			if (typeof this.options.verifyClient == 'function') {
			var info = {
			origin: origin,
			secure: typeof req.connection.authorized !== 'undefined' \|\| typeof req.connection.encrypted !== 'undefined',
			req: req
			};
			if (this.options.verifyClient.length == 2) {
			var self = this;
			this.options.verifyClient(info, function(result, code, name) {
			if (typeof code === 'undefined') code = 401;
			if (typeof name === 'undefined') name = http.STATUS_CODES[code];

			if (!result) abortConnection(socket, code, name);
			else onClientVerified.apply(self);
			});
			return;
			}
			else if (!this.options.verifyClient(info)) {
			abortConnection(socket, 401, 'Unauthorized');
			return;
			}
			}

			// no client verification required
			onClientVerified();
			}

			function acceptExtensions(offer) {
			var extensions = {};
			var options = this.options.perMessageDeflate;
			var maxPayload = this.options.maxPayload;
			if (options && offer[PerMessageDeflate.extensionName]) {
			var perMessageDeflate = new PerMessageDeflate(options !== true ? options : {}, true, maxPayload);
			perMessageDeflate.accept(offer[PerMessageDeflate.extensionName]);
			extensions[PerMessageDeflate.extensionName] = perMessageDeflate;
			}
			return extensions;
			}

			function abortConnection(socket, code, name) {
			try {
			var response = [
			'HTTP/1.1 ' + code + ' ' + name,
			'Content-type: text/html'
			];
			socket.write(response.concat('', '').join('\r\n'));
			}
			catch (e) { /* ignore errors - we've aborted this connection */ }
			finally {
			// ensure that an early aborted connection is shut down completely
			try { socket.destroy(); } catch (e) {}
			}
			}