--- /dev/null
+
+/*!
+ * Connect - session
+ * Copyright(c) 2010 Sencha Inc.
+ * Copyright(c) 2011 TJ Holowaychuk
+ * MIT Licensed
+ */
+
+/**
+ * Module dependencies.
+ */
+
+var Session = require('./session/session')
+ , MemoryStore = require('./session/memory')
+ , Cookie = require('./session/cookie')
+ , Store = require('./session/store')
+ , utils = require('./../utils')
+ , parse = require('url').parse
+ , crypto = require('crypto');
+
+// environment
+
+var env = process.env.NODE_ENV;
+
+/**
+ * Expose the middleware.
+ */
+
+exports = module.exports = session;
+
+/**
+ * Expose constructors.
+ */
+
+exports.Store = Store;
+exports.Cookie = Cookie;
+exports.Session = Session;
+exports.MemoryStore = MemoryStore;
+
+/**
+ * Warning message for `MemoryStore` usage in production.
+ */
+
+var warning = 'Warning: connection.session() MemoryStore is not\n'
+ + 'designed for a production environment, as it will leak\n'
+ + 'memory, and obviously only work within a single process.';
+
+/**
+ * Default finger-printing function.
+ */
+
+function defaultFingerprint(req) {
+ return req.headers['user-agent'] || '';
+};
+
+/**
+ * Paths to ignore, defaulting to `/favicon.ico`.
+ */
+
+exports.ignore = ['/favicon.ico'];
+
+/**
+ * Setup session store with the given `options`.
+ *
+ * Session data is _not_ saved in the cookie itself, however
+ * cookies are used, so we must use the [cookieParser()](middleware-cookieParser.html)
+ * middleware _before_ `session()`.
+ *
+ * Examples:
+ *
+ * connect.createServer(
+ * connect.cookieParser()
+ * , connect.session({ secret: 'keyboard cat' })
+ * );
+ *
+ * Options:
+ *
+ * - `key` cookie name defaulting to `connect.sid`
+ * - `store` Session store instance
+ * - `fingerprint` Custom fingerprint generating function
+ * - `cookie` Session cookie settings, defaulting to `{ path: '/', httpOnly: true, maxAge: 14400000 }`
+ * - `secret` Secret string used to compute hash
+ *
+ * Ignore Paths:
+ *
+ * By default `/favicon.ico` is the only ignored path, all others
+ * will utilize sessions, to manipulate the paths ignored, use
+ * `connect.session.ignore.push('/my/path')`. This works for _full_
+ * pathnames only, not segments nor substrings.
+ *
+ * connect.session.ignore.push('/robots.txt');
+ *
+ * ## req.session
+ *
+ * To store or access session data, simply use the request property `req.session`,
+ * which is (generally) serialized as JSON by the store, so nested objects
+ * are typically fine. For example below is a user-specific view counter:
+ *
+ * connect(
+ * connect.cookieParser()
+ * , connect.session({ secret: 'keyboard cat', cookie: { maxAge: 60000 }})
+ * , connect.favicon()
+ * , function(req, res, next){
+ * var sess = req.session;
+ * if (sess.views) {
+ * res.setHeader('Content-Type', 'text/html');
+ * res.write('<p>views: ' + sess.views + '</p>');
+ * res.write('<p>expires in: ' + (sess.cookie.maxAge / 1000) + 's</p>');
+ * res.end();
+ * sess.views++;
+ * } else {
+ * sess.views = 1;
+ * res.end('welcome to the session demo. refresh!');
+ * }
+ * }
+ * ).listen(3000);
+ *
+ * ## Session#regenerate()
+ *
+ * To regenerate the session simply invoke the method, once complete
+ * a new SID and `Session` instance will be initialized at `req.session`.
+ *
+ * req.session.regenerate(function(err){
+ * // will have a new session here
+ * });
+ *
+ * ## Session#destroy()
+ *
+ * Destroys the session, removing `req.session`, will be re-generated next request.
+ *
+ * req.session.destroy(function(err){
+ * // cannot access session here
+ * });
+ *
+ * ## Session#touch()
+ *
+ * Updates the `.maxAge`, and `.lastAccess` properties. Typically this is
+ * not necessary to call, as the session middleware does this for you.
+ *
+ * ## Session#cookie
+ *
+ * Each session has a unique cookie object accompany it. This allows
+ * you to alter the session cookie per visitor. For example we can
+ * set `req.session.cookie.expires` to `false` to enable the cookie
+ * to remain for only the duration of the user-agent.
+ *
+ * ## Session#maxAge
+ *
+ * Alternatively `req.session.cookie.maxAge` will return the time
+ * remaining in milliseconds, which we may also re-assign a new value
+ * to adjust the `.expires` property appropriately. The following
+ * are essentially equivalent
+ *
+ * var hour = 3600000;
+ * req.session.cookie.expires = new Date(Date.now() + hour);
+ * req.session.cookie.maxAge = hour;
+ *
+ * For example when `maxAge` is set to `60000` (one minute), and 30 seconds
+ * has elapsed it will return `30000` until the current request has completed,
+ * at which time `req.session.touch()` is called to update `req.session.lastAccess`,
+ * and reset `req.session.maxAge` to its original value.
+ *
+ * req.session.cookie.maxAge;
+ * // => 30000
+ *
+ * Session Store Implementation:
+ *
+ * Every session store _must_ implement the following methods
+ *
+ * - `.get(sid, callback)`
+ * - `.set(sid, session, callback)`
+ * - `.destroy(sid, callback)`
+ *
+ * Recommended methods include, but are not limited to:
+ *
+ * - `.length(callback)`
+ * - `.clear(callback)`
+ *
+ * For an example implementation view the [connect-redis](http://github.com/visionmedia/connect-redis) repo.
+ *
+ * @param {Object} options
+ * @return {Function}
+ * @api public
+ */
+
+function session(options){
+ var options = options || {}
+ , key = options.key || 'connect.sid'
+ , secret = options.secret
+ , store = options.store || new MemoryStore
+ , fingerprint = options.fingerprint || defaultFingerprint
+ , cookie = options.cookie;
+
+ // notify user that this store is not
+ // meant for a production environment
+ if ('production' == env && store instanceof MemoryStore) {
+ console.warn(warning);
+ }
+
+ // ensure secret is present
+ if (!secret) {
+ throw new Error('connect.session({ secret: "string" }) required for security');
+ }
+
+ // session hashing function
+ store.hash = function(req, base) {
+ return crypto
+ .createHmac('sha256', secret)
+ .update(base + fingerprint(req))
+ .digest('base64')
+ .replace(/=*$/, '');
+ };
+
+ // generates the new session
+ store.generate = function(req){
+ var base = utils.uid(24);
+ var sessionID = base + '.' + store.hash(req, base);
+ req.sessionID = sessionID;
+ req.session = new Session(req);
+ req.session.cookie = new Cookie(cookie);
+ };
+
+ return function session(req, res, next) {
+ // self-awareness
+ if (req.session) return next();
+
+ // parse url
+ var url = parse(req.url)
+ , path = url.pathname;
+
+ // ignorable paths
+ if (~exports.ignore.indexOf(path)) return next();
+
+ // expose store
+ req.sessionStore = store;
+
+ // proxy writeHead() to Set-Cookie
+ var writeHead = res.writeHead;
+ res.writeHead = function(status, headers){
+ if (req.session) {
+ var cookie = req.session.cookie;
+ // only send secure session cookies when there is a secure connection.
+ // proxySecure is a custom attribute to allow for a reverse proxy
+ // to handle SSL connections and to communicate to connect over HTTP that
+ // the incoming connection is secure.
+ var secured = cookie.secure && (req.connection.encrypted || req.connection.proxySecure);
+ if (secured || !cookie.secure) {
+ res.setHeader('Set-Cookie', cookie.serialize(key, req.sessionID));
+ }
+ }
+
+ res.writeHead = writeHead;
+ return res.writeHead(status, headers);
+ };
+
+ // proxy end() to commit the session
+ var end = res.end;
+ res.end = function(data, encoding){
+ res.end = end;
+ if (req.session) {
+ // HACK: ensure Set-Cookie for implicit writeHead()
+ if (!res._header) res._implicitHeader();
+ req.session.resetMaxAge();
+ req.session.save(function(){
+ res.end(data, encoding);
+ });
+ } else {
+ res.end(data, encoding);
+ }
+ };
+
+ // session hashing
+ function hash(base) {
+ return store.hash(req, base);
+ }
+
+ // generate the session
+ function generate() {
+ store.generate(req);
+ }
+
+ // get the sessionID from the cookie
+ req.sessionID = req.cookies[key];
+
+ // make a new session if the browser doesn't send a sessionID
+ if (!req.sessionID) {
+ generate();
+ next();
+ return;
+ }
+
+ // check the fingerprint
+ var parts = req.sessionID.split('.');
+ if (parts[1] != hash(parts[0])) {
+ generate();
+ next();
+ return;
+ }
+
+ // generate the session object
+ var pause = utils.pause(req);
+ store.get(req.sessionID, function(err, sess){
+ // proxy to resume() events
+ var _next = next;
+ next = function(err){
+ _next(err);
+ pause.resume();
+ }
+
+ // error handling
+ if (err) {
+ if ('ENOENT' == err.code) {
+ generate();
+ next();
+ } else {
+ next(err);
+ }
+ // no session
+ } else if (!sess) {
+ generate();
+ next();
+ // populate req.session
+ } else {
+ store.createSession(req, sess);
+ next();
+ }
+ });
+ };
+};