Google Channel API sending message with token - google-app-engine

In documents it says 'client_id' part can actually be the token, however it doesn't work. Anyone know why?
https://developers.google.com/appengine/docs/python/channel/functions
If the client_id parameter is actually a token returned by a create_channel call then send_message can be used for different versions of the app. For instance you could create the channel on the front end and then send messages from a backend of the app.
the reason i want to use this, is because i want to send messages to anonymous users as well, without requiring them to login. i don't know if it is possible to assign them a 'client_id' if token doesn't work.
this is how i am creating the token
user = users.get_current_user()
if user:
token = channel.create_channel(user.user_id())
else:
token = channel.create_channel(str(uuid.uuid4()))
then injecting into client
template_values = {
'token' : token,
}
on the client side open the channel
openChannel = function() {
var token = '{{ token }}';
var channel = new goog.appengine.Channel(token);
var handler = {
'onopen': onOpened,
'onmessage': onMessage,
'onerror': function() {},
'onclose': function() {}
};
var socket = channel.open(handler);
socket.onopen = onOpened;
socket.onmessage = onMessage;
}
now send a message
var xhr = new XMLHttpRequest();
xhr.open('POST', path, true);
xhr.send();
in the server,
when the message is received send back a message using the token
channel.send_message(token, someMessage)
back to client
onMessage = function(m) {
alert("you have some message");
}
this sequence works fine if client_id() is used instead of token when calling send_message

In response to btevfik's initial question: Allowing tokens or client_id in send_message is a feature released in 1.7.5 (very recently). Some people may not be familiar with it yet so therefore they suggest to use client_id. Both should work!
The only thing that I can see in your code is the fact that you should not rely on token variable to be correct in between two requests. They may not even land on the same instance of the app. If you share your code with more details I may be able to spot something. The proper way would be to either store the token in the datastore or pass it from the client as a parameter when you send the message that will trigger a message back.
The purpose of this feature was to allow people to send messages from backends (or other versions). Before was not possible whereas now you can do it if you use directly the tokens instead of the client_id.

Long time this post has been around, but just curious about your usage of the token global variable?
I don't see this code:
global token
before you set the token
user = users.get_current_user()
if user:
token = channel.create_channel(user.user_id())
else:
token = channel.create_channel(str(uuid.uuid4()))
If that code is missing, then token will be set in the local scope of the function above and not globally. So, the token value used later will be None (or to what ever the token was initialised with.)
Just a thought, if its still relevant.

I don't think you actually have a problem here.
You are able to send messages to users that are logged in or not.
The problem you are having I think is knowing that there are multiple ways to use the channel API re: tokens.
https://developers.google.com/appengine/docs/python/channel/overview#Life_of_a_Typical_Channel_Message
In this example, it shows the JavaScript client explicitly requests a token and sends its Client ID to the server. In contrast, you could choose to design your application to inject the token into the client before the page loads in the browser, or some other implementation if preferred.
This diagram shows the creation of a channel on the server. In this
example, it shows the JavaScript client explicitly requests a token
and sends its Client ID to the server. In contrast, you could choose
to design your application to inject the token into the client before
the page loads in the browser, or some other implementation if
preferred.
Here's my demo implementation, hope it helps somehow: https://github.com/Paul1234321/channelapidemo.git
Here's the code for creating the channel on GAE:
client_id = str(uuid.uuid4()).replace("-",'')
channel_token = channel.create_channel(client_id)
And in the JS:
channel = new goog.appengine.Channel('{{ token }}');
Have a look at it in action: http://pppredictor.appspot.com/

You shouldn't store request-specific values in global variables. Store them in a cookie or pass them as a request parameter instead.

Related

How to decode access token from Microsoft OAuth2

I am building a web application using CakePHP 4.1.
And it has authorization from Microsoft Active Directory(OAuth2).
What I am going to do is to decode the access token and redirect to Microsoft login page when it is expired.
So I can get token from authorization like this.
https://login.microsoftonline.com/TENANT_ID/oauth2/v2.0/authorize?client_id=CLIENT_ID&response_type=token&redirect_uri=LOGIN_REDIRECT_URI&response_mode=form_post&scope=offline_access https://graph.microsoft.com/.default'
I tried to decode using firebase/jwt, but I am not sure what should be $key.
JWT::decode($accessToken, $key, array('RS256'))
I can get the decoded result if I enter the token in jwt.ms
I don't have any special claims, so $key should be plain.
And I want to know if there is another way to decode jwt.
Firebase JWT only supports decoding with signature validation, so a key is always required.
You can manually decode the token, it's just JSON as base64, however without validation there's no way to know whether the information hasn't been forged, so I wouldn't trust any information obtained that way, not even the expiration time.
Usually OAuth APIs return an expiration time in the response for access token requests (and so does Microsofts Identity Platform API), which your app can store alongside the token and use for checking for possible token expiration.
Refreshing upon receiving invalid token errors from the API is usually an option too, then you don't need to care about the expiration time yourself at all.
I would certainly suggest any of those options over trusting arbitrary client data.
That being said, if you still want the unvalidated expiration time from the token, just do what Firebase JWT does internally:
$tks = \explode('.', $accessToken);
if (\count($tks) != 3) {
throw new \UnexpectedValueException('Wrong number of segments');
}
list($headb64, $bodyb64, $cryptob64) = $tks;
if (null === ($header = JWT::jsonDecode(JWT::urlsafeB64Decode($headb64)))) {
throw new \UnexpectedValueException('Invalid header encoding');
}
if (null === $payload = JWT::jsonDecode(JWT::urlsafeB64Decode($bodyb64))) {
throw new \UnexpectedValueException('Invalid claims encoding');
}
if (false === ($sig = JWT::urlsafeB64Decode($cryptob64))) {
throw new \UnexpectedValueException('Invalid signature encoding');
}
https://github.com/firebase/php-jwt/blob/v5.2.0/src/JWT.php#L81-L94

AppEngine channel API: duplicate messages client side

I am trying to use the Channel API to push updates from server to the client. The flow is the user presses a button which triggers a server side action that generates a lot of logs. I want to display the logs to the user "in real time".
When I first load the page it I get all the messages, no problem. If I trigger the action a second time without refreshing the page in my browser, then all messages appear twice. Here is the set up portion of the channel that is tied to the page onLoad event. With resulting console logs I gathered that the onMessage() method is being invoked more than once when the page is not refreshed. Looks like I need to "kill" earlier sockets in some way, but could not find a way in the official documentation. Can someone point me in the right direction to get rid of the spurious messages?
// First fetch a token for the async communication channel and
// create the socket
$.post("/app/channels", {'op':'fetch', 'id' : nonce},
function (data, status, xhr) {
if (status == "success") {
data = JSON.parse(data);
token = data["token"];
console.log("Cookie: " + get_mp_did() + "; token: " + token);
var channel = new goog.appengine.Channel(token);
var handler = {
'onopen': onOpened,
'onmessage': onMessage,
'onerror': function() {
$("#cmd_output").append('Channel error.<br/>');
},
'onclose': function() {
$("#cmd_output").append('The end.<br/>');
$.post("/app/channels", {'op':'clear'});
}
};
var socket = channel.open(handler);
socket.onopen = onOpened;
socket.onmessage = onMessage;
}
});
onOpened = function() {
$("#cmd_output").empty();
};
onMessage = function(data) {
message = JSON.parse(data.data)['message'];
$("#cmd_output").append(message);
console.log('Got this sucker: ' + message);
}
If I understand your post and code correctly, the user clicks on a button which calls the $.post() function. The server code is responsible to create the channel in GAE as response to a /app/channels request. I think that your server in fact creates a new channel client ID / token with every subsequent request. Since the page is not reloaded, any subsequent request would add a new channel to this client. And all these channels would be still connected (hence, no page refresh).
I assume your server code has all channels associated to a user, and you send the message to a user utilizing all channels? Such pattern would result in this behavior. You can verify my assumption by clicking 3 or four times on the button with-out page refresh. The log output would be multiplied by the factor of 3 or 4.
I suggest, that you store the token in the client and on the server. Then make a modification to your client JS. If a channel is already created store the token value and provide it to any subsequent request to /app/channels. Modify the server so it will not create a new channel, if a token is provided with the request. If the token links to an existing valid channel, re-use the channel and return the same token in the response. You may need to add some more details for disconnected or expired channels, maybe also a cron-job to delete all expired channels after a while.

How do I send user specific data with socket.io and laravel?

I am not sure how to word this question right, but here I go. I have laravel, angular, node w/socket.io and I am also using JWT for authentication. My end goal is to be able to send real time update notifications to specific users. For the life of me, I cannot seem to get how the workflow would be.
My initial though was to send the jwt within the handshake and then use then in node to do http requests to get data, and then return said data. In another words, when a specific event is fired, node will already have the token, send request to laravel for specific information.
Can someone please explain to me how sending user specific data via socket.io in this architecture?
I found this great article : https://www.ukietech.com/blog/programming/step-by-step-instruction-of-setting-up-real-time-secure-broadcasting-with-laravel-5-1-socket-io-and-redis/
This set me on the right track.
First I need to pass in my JWT into the socket:
var socket = io('http://192.168.10.10:3000', {query: "Authorization="+$rootScope.$storage.satellizer_token});
Next I actually verify the token.. again. I know this may be overkill, but I want to know that what hits the socket is legit.
io.use(function(socket, next){
if (socket.handshake.query.Authorization) {
var config = {
url:'http://192.168.10.10/api/auth',
headers:{
Authorization:'Bearer '+socket.handshake.query.Authorization
}
};
request.get(config,function(error,response,body){
socket.userId = JSON.parse(body).id;
next();
});
}
// call next() with an Error if you need to reject the connection.
next(new Error('Authentication error'));
});
The request in this block of code returns a user object based on the authenticated token. Refer to JWTAuth for more.
Then on connection I will assign the user to a unique channel.
io.on('connection',function(socket){
socket.join('userNotifications.'+socket.userId);
console.log('user joined room: userNotifications.'+socket.userId);
});
Then broadcast the event:
notifications.on('pmessage', function(subscribed, channel, message) {
var m = JSON.parse(message);
io.emit(channel+":"+m.event, message);
});
Back on the client side I listen for the channel. the var user is the user id.
socket.on('userNotifications.'+ user+':App\\Events\\notifications', function(message){
console.log(message);
});

MEANJS: Security in SocketIO

Situation
I'm using the library SocketIO in my MEAN.JS application.
in NodeJS server controller:
var socketio = req.app.get('socketio');
socketio.sockets.emit('article.created.'+req.user._id, data);
in AngularJS client controller:
//Creating listener
Socket.on('article.created.'+Authentication.user._id, callback);
//Destroy Listener
$scope.$on('$destroy',function(){
Socket.removeListener('article.created.'+Authentication.user._id, callback);
});
Okey. Works well...
Problem
If a person (hacker or another) get the id of the user, he can create in another application a listener in the same channel and he can watch all the data that is sends to the user; for example all the notificacions...
How can I do the same thing but with more security?
Thanks!
Some time ago I stumbled upon the very same issue. Here's my solution (with minor modifications - used in production).
We will use Socket.IO namespaces to create private room for each user. Then we can emit messages (server-side) to specific rooms. In our case - only so specific user can receive them.
But to create private room for each connected user, we have to verify their identify first. We'll use simple piece of authentication middleware for that, supported by Socket.IO since its 1.0 release.
1. Authentication middleware
Since its 1.0 release, Socket.IO supports middleware. We'll use it to:
Verify connecting user identify, using JSON Web Token (see jwt-simple) he sent us as query parameter. (Note that this is just an example, there are many other ways to do this.)
Save his user id (read from the token) within socket.io connection instance, for later usage (in step 2).
Server-side code example:
var io = socketio.listen(server); // initialize the listener
io.use(function(socket, next) {
var handshake = socket.request;
var decoded;
try {
decoded = jwt.decode(handshake.query().accessToken, tokenSecret);
} catch (err) {
console.error(err);
next(new Error('Invalid token!'));
}
if (decoded) {
// everything went fine - save userId as property of given connection instance
socket.userId = decoded.userId; // save user id we just got from the token, to be used later
next();
} else {
// invalid token - terminate the connection
next(new Error('Invalid token!'));
}
});
Here's example on how to provide token when initializing the connection, client-side:
socket = io("http://stackoverflow.com/", {
query: 'accessToken=' + accessToken
});
2. Namespacing
Socket.io namespaces provide us with ability to create private room for each connected user. Then we can emit messages into specific room (so only users within it will receive them, as opposed to every connected client).
In previous step we made sure that:
Only authenticated users can connect to our Socket.IO interface.
For each connected client, we saved user id as property of socket.io connection instance (socket.userId).
All that's left to do is joining proper room upon each connection, with name equal to user id of freshly connected client.
io.on('connection', function(socket){
socket.join(socket.userId); // "userId" saved during authentication
// ...
});
Now, we can emit targeted messages that only this user will receive:
io.in(req.user._id).emit('article.created', data); // we can safely drop req.user._id from event name itself

Building realtime app using Laravel and Latchet websocket

I'm building a closed app (users need to authenticate in order to use it). I'm having trouble in identifying the currently authenticated user from my Latchet session. Since apache does not support long-lived connections, I host Latchet on a separate server instance. This means that my users receive two session_id's. One for each connection. I want to be able to identify the current user for both connections.
My client code is a SPA based on AngularJS. For client WS, I'm using the Autobahn.ws WAMP v1 implementation. The ab framework specifies methods for authentication: http://autobahn.ws/js/reference_wampv1.html#session-authentication, but how exactly do I go about doing this?
Do I save the username and password on the client and retransmit these once login is performed (which by the way is separate from the rest of my SPA)? If so, won't this be a security concearn?
And what will receive the auth request server side? I cannot find any examples of this...
Please help?
P.S. I do not have reputation enough to create the tag "Latchet", so I'm using Ratchet (which Latchet is built on) instead.
Create an angularjs service called AuthenticationService, inject where needed and call it with:
AuthenticationService.check('login_name', 'password');
This code exists in a file called authentication.js. It assumes that autobahn is already included. I did have to edit this code heavily removing all the extra crap I had in it,it may have a syntax error or two, but the idea is there.
angular.module(
'top.authentication',
['top']
)
.factory('AuthenticationService', [ '$rootScope', function($rootScope) {
return {
check: function(aname, apwd) {
console.log("here in the check function");
$rootScope.loginInfo = { channel: aname, secret: apwd };
var wsuri = 'wss://' + '192.168.1.11' + ':9000/';
$rootScope.loginInfo.wsuri = wsuri;
ab.connect(wsuri,
function(session) {
$rootScope.loginInfo.session = session;
console.log("connected to " + wsuri);
onConnect(session);
},
function(code,reason) {
$rootScope.loginInfo.session = null;
if ( code == ab.CONNECTION_UNSUPPORTED) {
console.log(reason);
} else {
console.log('failed');
$rootScope.isLoggedIn = 'false';
}
}
);
function onConnect(sess) {
console.log('onConnect');
var wi = $rootScope.loginInfo;
sess.authreq(wi.channel).then(
function(challenge) {
console.log("onConnect().then()");
var secret = ab.deriveKey(wi.secret,JSON.parse(challenge).authextra);
var signature = sess.authsign(challenge, secret);
sess.auth(signature).then(onAuth, ab.log);
},ab.log
);
}
function onAuth(permission) {
$rootScope.isLoggedIn = 'true';
console.log("authentication complete");
// do whatever you need when you are logged in..
}
}
};
}])
then you need code (as you point out) on the server side. I assume your server side web socket is php coding. I can't help with that, haven't coded in php for over a year. In my case, I use python, I include the autobahn gear, then subclass WampCraServerProtocol, and replace a few of the methods (onSessionOpen, getAuthPermissions, getAuthSecret, onAuthenticated and onClose) As you can envision, these are the 'other side' of the angular code knocking at the door. I don't think autobahn supports php, so, you will have to program the server side of the authentication yourself.
Anyway, my backend works much more like what #oberstat describes. I establish authentication via old school https, create a session cookie, then do an ajax requesting a 'ticket' (which is a temporary name/password which i associate with the web authenticated session). It is a one use name/password and must be used in a few seconds or it disappears. The point being I don't have to keep the user's credentials around, i already have the cookie/session which i can create tickets that can be used. this has a neat side affect as well, my ajax session becomes related to my web socket session, a query on either is attributed to the same session in the backend.
-g
I can give you a couple of hints regarding WAMP-CRA, which is the authentication mechnism this is referring:
WAMP-CRA does not send passwords over the wire. It works by a challenge-response scheme. The client and server have a shared secret. To authenticate a client, the server will send a challenge (something random) that the client needs to sign - using the secret. And only the signature is sent back. The client might store the secret in browser local storage. It's never sent.
In a variant of above, the signing of the challenge the server sends is not directly signed within the client, but the client might let the signature be created from an Ajax request. This is useful when the client was authenticated using other means already (e.g. classical cookie based), and the signing can then be done in the classical web app that was authenticating.
Ok, Greg was kind enough to provide a full example of the client implementation on this, so I wont do anything more on that. It works with just a few tweaks and modifications to almost any use-case I can think of. I will mark his answer as the correct one. But his input only covered the theory of the backend implementation, so I will try to fill in the blanks here for postparity.
I have to point out though, that the solution here is not complete as it does not give me a shared session between my SPA/REST connection and my WS connection.
I discovered that the authentication request transmitted by autobahn is in fact a variant of RPC and for some reason has hardcoded topic names curiously resembling regular url's:
- 'http://api.wamp.ws/procedure#authreq' - for auth requests
- 'http://api.wamp.ws/procedure#auth' - for signed auth client responses
I needed to create two more routes in my Laravel routes.php
// WS CRA routes
Latchet::topic('http://api.wamp.ws/procedure#authreq', 'app\\socket\\AuthReqController');
Latchet::topic('http://api.wamp.ws/procedure#auth', 'app\\socket\\AuthReqController');
Now a Latchet controller has 4 methods: subscribe, publish, call and unsubscribe. Since both the authreq and the auth calls made by autobahn are RPC calls, they are handled by the call method on the controller.
The solution first proposed by oberstet and then backed up by Greg, describes a temporary auth key and secret being generated upon request and held temporarily just long enough to be validated by the WS CRA procedure. I've therefore created a REST endpoint which generates a persisted key value pair. The endpoint is not included here, as I am sure that this is trivial.
class AuthReqController extends BaseTopic {
public function subscribe ($connection, $topic) { }
public function publish ($connection, $topic, $message, array $exclude, array $eligible) { }
public function unsubscribe ($connection, $topic) { }
public function call ($connection, $id, $topic, array $params) {
switch ($topic) {
case 'http://api.wamp.ws/procedure#authreq':
return $this->getAuthenticationRequest($connection, $id, $topic, $params);
case 'http://api.wamp.ws/procedure#auth':
return $this->processAuthSignature($connection, $id, $topic, $params);
}
}
/**
* Process the authentication request
*/
private function getAuthenticationRequest ($connection, $id, $topic, $params) {
$auth_key = $params[0]; // A generated temporary auth key
$tmpUser = $this->getTempUser($auth_key); // Get the key value pair as persisted from the temporary store.
if ($tmpUser) {
$info = [
'authkey' => $tmpUser->username,
'secret' => $tmpUser->secret,
'timestamp' => time()
];
$connection->callResult($id, $info);
} else {
$connection->callError($id, $topic, array('User not found'));
}
return true;
}
/**
* Process the final step in the authentication
*/
private function processAuthSignature ($connection, $id, $topic, $params) {
// This should do something smart to validate this response.
// The session should be ours right now. So store the Auth::user()
$connection->user = Auth::user(); // A null object is stored.
$connection->callResult($id, array('msg' => 'connected'));
}
private function getTempUser($auth_key) {
return TempAuth::findOrFail($auth_key);
}
}
Now somewhere in here I've gone wrong. Cause if I were supposed to inherit the ajax session my app holds, I would be able to call Auth::user() from any of my other WS Latchet based controllers and automatically be presented with the currently logged in user. But this is not the case. So if somebody see what I'm doing wrong, give me a shout. Please!
Since I'm unable to get the shared session, I'm currently cheating by transmitting the real username as a RPC call instead of performing a full CRA.

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