Add ability to generate secret dynamically

This allow you to pass a function instead of an string in order to
generate secret based on the new connection features.

README.md

@@ -101,6 +101,31 @@ socket.on("error", function(error) {
     console.log("User's token has expired");
   }
 });
+```
+## Getting the secret dynamically
+You can pass a function instead of an string when configuring secret.
+This function receives the request, the decoded token and a callback. This
+way, you are allowed to use a different secret based on the request and / or
+the provided token.
+
+__Server side__:
+
+```javascript
+var SECRETS = {
+  'user1': 'secret 1',
+  'user2': 'secret 2'
+}
+
+io.use(socketioJwt.authorize({
+  secret: function(request, decodedToken, callback) {
+    // SECRETS[decodedToken.userId] will be used a a secret or
+    // public key for connection user.
+
+    callback(null, SECRETS[decodedToken.userId]);
+  },
+  handshake: false
+}));
+
 ```
 
 ## Contribute

lib/index.js

@@ -40,19 +40,19 @@ function noQsMethod(options) {
             return; // stop logic, socket will be close on next tick
           }
       };
-      
+
       if(typeof data.token !== "string") {
         return onError({message: 'invalid token datatype'}, 'invalid_token');
       }
-      
-      jwt.verify(data.token, options.secret, options, function(err, decoded) {
+
+      var onJwtVerificationReady = function(err, decoded) {
 
         if (err) {
           return onError(err, 'invalid_token');
         }
 
         // success handler
-        var onSuccess = function(){
+        var onSuccess = function() {
           socket.decoded_token = decoded;
           socket.emit('authenticated');
           if (server.$emit) {
@@ -73,9 +73,18 @@ function noQsMethod(options) {
         } else {
           onSuccess();
         }
-      });
-    });
+      };
 
+      var onSecretReady = function(err, secret) {
+        if (err || !secret) {
+          return onError(err, 'invalid_secret');
+        }
+
+        jwt.verify(data.token, secret, options, onJwtVerificationReady);
+      };
+
+      getSecret(socket.request, options.secret, data.token, onSecretReady);
+    });
   };
 }
 
@@ -140,18 +149,57 @@ function authorize(options, onConnection) {
       return auth.fail(error, data, accept);
     }
 
-    jwt.verify(token, options.secret, options, function(err, decoded) {
+    var onJwtVerificationReady = function(err, decoded) {
 
       if (err) {
-        error = new UnauthorizedError('invalid_token', err);
+        error = new UnauthorizedError(err.code || 'invalid_token', err);
         return auth.fail(error, data, accept);
       }
 
       data.decoded_token = decoded;
 
       return auth.success(data, accept);
-    });
+    };
+
+    var onSecretReady = function(err, secret) {
+      if (err) {
+        error = new UnauthorizedError(err.code || 'invalid_secret', err);
+        return auth.fail(error, data, accept);
+      }
+
+      jwt.verify(token, secret, options, onJwtVerificationReady);
+    };
+
+    getSecret(req, options.secret, token, onSecretReady);
   };
 }
 
+function getSecret(request, secret, token, callback) {
+  if (typeof secret === 'function') {
+    if (!token) {
+      return callback({ code: 'invalid_token', message: 'jwt must be provided' });
+    }
+
+    var parts = token.split('.');
+
+    if (parts.length < 3) {
+      return callback({ code: 'invalid_token', message: 'jwt malformed' });
+    }
+
+    if (parts[2].trim() === '') {
+      return callback({ code: 'invalid_token', message: 'jwt signature is required' });
+    }
+
+    var decodedToken = jwt.decode(token);
+
+    if (!decodedToken) {
+      return callback({ code: 'invalid_token', message: 'jwt malformed' });
+    }
+
+    secret(request, decodedToken, callback);
+  } else {
+    callback(null, secret);
+  }
+};
+
 exports.authorize = authorize;

test/authorizer_secret_function_noqs.test.js

@@ -0,0 +1,77 @@
+var fixture = require('./fixture/secret_function');
+var request = require('request');
+var io = require('socket.io-client');
+
+describe('authorizer with secret function', function () {
+
+  //start and stop the server
+  before(function (done) {
+    fixture.start({
+      handshake: false
+    } , done);
+  });
+
+  after(fixture.stop);
+
+  describe('when the user is not logged in', function () {
+
+    describe('and when token is not valid', function() {
+      beforeEach(function (done) {
+        request.post({
+          url: 'http://localhost:9000/login',
+          json: { username: 'invalid_signature', password: 'Pa123' }
+        }, function (err, resp, body) {
+          this.invalidToken = body.token;
+          done();
+        }.bind(this));
+      });
+
+      it('should emit unauthorized', function (done){
+        var socket = io.connect('http://localhost:9000', {
+          'forceNew':true,
+        });
+
+        var invalidToken = this.invalidToken;
+        socket.on('unauthorized', function() {
+          done();
+        });
+
+        socket.on('connect', function(){
+          socket
+            .emit('authenticate', { token: invalidToken + 'ass' })
+        });
+      });
+    });
+
+  });
+
+  describe('when the user is logged in', function() {
+
+    beforeEach(function (done) {
+      request.post({
+        url: 'http://localhost:9000/login',
+        json: { username: 'valid_signature', password: 'Pa123' }
+      }, function (err, resp, body) {
+        this.token = body.token;
+        done();
+      }.bind(this));
+    });
+
+    it('should do the handshake and connect', function (done){
+      var socket = io.connect('http://localhost:9000', {
+        'forceNew':true,
+      });
+      var token = this.token;
+      socket.on('connect', function(){
+        socket.on('echo-response', function () {
+          socket.close();
+          done();
+        }).on('authenticated', function () {
+          socket.emit('echo');
+        })
+        .emit('authenticate', { token: token })
+      });
+    });
+  });
+
+});

test/authorizer_secret_function_qs.test.js

@@ -0,0 +1,73 @@
+var fixture = require('./fixture/secret_function');
+var request = require('request');
+var io = require('socket.io-client');
+
+describe('authorizer with secret function', function () {
+
+  //start and stop the server
+  before(fixture.start);
+  after(fixture.stop);
+
+  describe('when the user is not logged in', function () {
+
+    it('should emit error with unauthorized handshake', function (done){
+      var socket = io.connect('http://localhost:9000?token=boooooo', {
+        'forceNew': true
+      });
+
+      socket.on('error', function(err){
+        err.message.should.eql("jwt malformed");
+        err.code.should.eql("invalid_token");
+        socket.close();
+        done();
+      });
+    });
+
+  });
+
+  describe('when the user is logged in', function() {
+
+    beforeEach(function (done) {
+      request.post({
+        url: 'http://localhost:9000/login',
+        json: { username: 'valid_signature', password: 'Pa123' }
+      }, function (err, resp, body) {
+        this.token = body.token;
+        done();
+      }.bind(this));
+    });
+
+    it('should do the handshake and connect', function (done){
+      var socket = io.connect('http://localhost:9000', {
+        'forceNew':true,
+        'query': 'token=' + this.token
+      });
+      socket.on('connect', function(){
+        socket.close();
+        done();
+      }).on('error', done);
+    });
+  });
+
+  describe('unsigned token', function() {
+    beforeEach(function () {
+      this.token = 'eyJhbGciOiJub25lIiwiY3R5IjoiSldUIn0.eyJuYW1lIjoiSm9obiBGb28ifQ.';
+    });
+
+    it('should not do the handshake and connect', function (done){
+      var socket = io.connect('http://localhost:9000', {
+        'forceNew':true,
+        'query': 'token=' + this.token
+      });
+      socket.on('connect', function () {
+        socket.close();
+        done(new Error('this shouldnt happen'));
+      }).on('error', function (err) {
+        socket.close();
+        err.message.should.eql("jwt signature is required");
+        done();
+      });
+    });
+  });
+
+});

test/fixture/secret_function.js

@@ -0,0 +1,89 @@
+var express = require('express');
+var http = require('http');
+
+var socketIo = require('socket.io');
+var socketio_jwt = require('../../lib');
+
+var jwt = require('jsonwebtoken');
+
+var xtend = require('xtend');
+var bodyParser = require('body-parser');
+
+var server, sio;
+var enableDestroy = require('server-destroy');
+
+exports.start = function (options, callback) {
+  var SECRETS = {
+    123: 'aaafoo super sercret',
+    555: 'other'
+  };
+
+  if(typeof options == 'function'){
+    callback = options;
+    options = {};
+  }
+
+  options = xtend({
+    secret: function(request, decodedToken, callback) {
+      callback(null, SECRETS[decodedToken.id]);
+    },
+    timeout: 1000,
+    handshake: true
+  }, options);
+
+  var app = express();
+
+  app.use(bodyParser.json());
+
+  app.post('/login', function (req, res) {
+    var profile = {
+      first_name: 'John',
+      last_name: 'Doe',
+      email: 'john@doe.com',
+      id: req.body.username === 'valid_signature' ? 123 : 555
+    };
+
+    // We are sending the profile inside the token
+    var token = jwt.sign(profile, SECRETS[123], { expiresIn: 60*60*5 });
+
+    res.json({token: token});
+  });
+
+  server = http.createServer(app);
+
+  sio = socketIo.listen(server);
+
+  if (options.handshake) {
+    sio.use(socketio_jwt.authorize(options));
+
+    sio.sockets.on('echo', function (m) {
+      sio.sockets.emit('echo-response', m);
+    });
+  } else {
+    sio.sockets
+      .on('connection', socketio_jwt.authorize(options))
+      .on('authenticated', function (socket) {
+        socket.on('echo', function (m) {
+          socket.emit('echo-response', m);
+        });
+      });
+  }
+
+  server.__sockets = [];
+  server.on('connection', function (c) {
+    server.__sockets.push(c);
+  });
+
+  server.listen(9000, callback);
+  enableDestroy(server);
+};
+
+exports.stop = function (callback) {
+  sio.close();
+  try {
+    server.destroy();
+  } catch (er) {}
+
+  callback();
+};
+