Occassional Oauth exceptions - user hasn't authorized the app - security

I am fairly sure my application is handling most things properly as it works 88-92% of the time, but way too often I am getting the following error:
(OAuthException - #200) (#200) The user hasn't authorized the application to perform this action
I don't understand how this is possible. When the user is requested to authorize the app, I do not see any way for them accept a subset of the permissions required (it's all or nothing). If they proceed, and I get an auth token, doesn't that mean my app has the needed access? If not, how are users doing that, and how can I prevent or at least detect it?
In terms of background, my application is a kiosk application that takes the user's photo and allows them to post it (or, more precisely, a link to it) on their facebook timeline. The kiosk gets the user's authorization, then passes the token and all other data to a central web service that then communicates with Facebook. This has been working 88-92% of the time for the past week. Despite no code changes or application configuration changes, prior to the past week it had been working 93-96% of the time for the couple weeks prior to that, and about 98% earlier than that.
Is there any way I can provide some details (usernames and auth tokens) to facebook for more analysis? PLEASE HELP!

Related

Advice on whether possible to display iframe already authenticated (credentials)

I have a problem that I need to solve for my client. The situation is that they have a lot of users on one platform (platform_1). In order to use the platform a user must be signed in, therefore these users (credentials) are given out to clients for them to use the platform. The problem is that one user (one set of credentials) may be given out to a few clients, therefore we cannot know which of the clients did what (in this case - bought something) on the platform.
Figured I would just create a new system where the client can be created and a set of credentials would be attached to that account, then I would just display an iframe of that platform (platform_1) with the attached credentials on the newly build platform and then I would be able to track what the user is doing in the platform.
But turns out iframe cannot handle credentials and also it would not be safe to use this method..
Also thought about scraping the whole platfrom (platform_1), which would work, but then I believe it would be extremely hard to do live auctions, for example scrape the live auction and display it on my system and let the user click on some buttons and the script would do the same on the platform_1, but the delays and overall usage could make it very hard.
I would like to kindly ask you to share your thoughts on ways this problem could be solved or whether it aint possible.

Having one backend manage authentication for a webapp and react native app

Im planning on making an application that has two parts two it:
React native mobile app
Browser web-app for desktop users
I'm trying to plan out how im going to manage the backend authentication for this (Node.js, passport.js). Ideally, I can just have one backend manage it, regardless of which type of client.
Lets say im going to ONLY have google auth (for simplicity). I don't need to hit googles API's for any information (like profile, contacts, etc), I just want them to login with a google account. My understanding so far is that theres two main ways (especially since im using passport.js).
jwt based approach
session based approach
For either approach, my issue arises when it comes to the react native app. Since I'm not able to use the HttpOnly cookie, im not sure how to safely store data. e.g
In the jwt approach, if the server administers an access token and a refresh token, the react native client can just store them both in the same place e.g https://github.com/mcodex/react-native-sensitive-info. Which means the refresh token is just as susceptible as the access token, which defeats the point of a refresh token, so might as well just have the access token be long lived.
In the session based approach, react native can just store the session id some where (like react-native-sensitive-info above), and the same problem arises
My current thoughts on what should be done:
It seems like theres no way of getting around the security issue of storing information in react native, so as of now I feel like im just going to follow the JWT approach, and store the access + refresh token in react-native-sensitive-info. However, this does mean that the login endpoint is going to return the access + refresh token in the body of the request when the User-agent is mobile. When the user agent is web then we should be able to set an httponly cookie. The only thing that I can think of is if there is a malicious request that masks the user agent (is this possible?), and then can receive the access + refresh token in the body and will be able to do whatever with that.
Performance Aside
A session based storage approach seems much simpler overall. Yes it does store state on the backend, but if we did the JWT approach we would have to store peoples refresh tokens somewhere on the backend anyway (If theres ever a scenario where we need to invalidate peoples refresh tokens, e.g on logout or damage prevention).
This way, say we have a sessions table, when a user logs out, or if we want to invalidate sessions, all we have to do is delete rows from that table. In the JWT method, if we want to invalidate a refresh token, we have to have a blocklist table (which will only keep growing in size, since refresh tokens shouldn't expire, but I guess they can be dropped after a long period of time). However, if you have LOTS of users, the sessions table could get large, which could cause performance issues (but you could probably just drop sessions over a certain age)
/Aside
Questions:
Ive noticed mobile applications have NEVER asked me to relogin with OAuth. Does that mean they're constantly using their refresh token whenever the access token expires? If theres no clear way to store that in a secure way in mobile, do they just have super long lasting access tokens?
Is all of this thinking overkill? Is it fine to just store a super long-lasting access-token in react native and just use that all the time? Then when the user presses 'logout' we can drop that from local storage?
Would a third party auth system like auth0 manage all of this for me?
I'll try to share my experiencies in different kinds of app, this way things may get more clear.
Authentication Method
On most of the mobile applications (with web applications) I've worked with long term access tokens on the mobile side, most of applications don't require the user to login each time you open the app. Usually we store the token in a Secure Storage.
In some cases I've worked with a memory database (Redis) to put the user's session it's really fast and you don't need to query your main database each request (this was used for a high availability system, it may be overkill for most usecases)
Some very specific solutions may require more security, this will depend on your product (like banks, and transactions apps or apps the keep sensitive data) in these cases I would recommend you to login the user every time he closes the app or stays inactive for to long. (this kind of solution usually relies on fingerprint/faceId libs)
My personal opinion on this matter is to go with jwt, it's easy to maintain on the server side if you need to change backends and has a more defined pattern to follow, but that's my opinion and if you have high demand or some specific usecase this may change.
Storage
Talking about the storage options, there are some good suggestions on where to save data like tokens in a secure way on the react native docs,a good option I've used sometime would be:
https://github.com/emeraldsanto/react-native-encrypted-storage
but you can see more options and it advantages here:
https://reactnative.dev/docs/security#secure-storage
Third party libs
They usually helps with the basics if your projects has the budget and not a lot of customization on the authentication process, usually if it's a brand new project (on the back and front end) they work well.
Most of them will handle most of the hurdle for you like token renovation but you should mind the price scalability for these kind of approach
Wish success on your project.

If I already have ../auth/documents.currentonly scope, do I also need ../auth/documents?

I'm transitioning a Google Docs add-on that was approved when the add-on concept first started (many years ago) from a Docs-only add-on to one that works for both Slides and Docs. In the process, I have had to redefine a lot of things (create a new project) and request authorization for OAuth scopes.
I had assumed that if my add-on had ../auth/documents.currentonly (which is truly all it needs), then I was good to go. I did have to request authorization for external_service and container.ui, which I obtained quickly from Google. So, I published the add-on, and all looked OK. I was able to install it on my test accounts, etc. I've seen the number of public users go from 0 to 63 in about a week.
However, I just got an obscure email from Google saying I had to take action because I didn't have the authorizations:
Apps requesting risky OAuth scopes that have not completed the OAuth developer verification process are limited to 100 new user grants.
The email doesn't specify what scope is risky, however. The OAuth consent screen shows all my APIs that needed authorization are approved (I also have an email showing they were granted authorization):
The consent screen doesn't allow me to request verification (the button is grayed) in its current state. I assume that, since no verification is requested or given for them, the currentonly scopes are not "risky".
I have replied to Google's email (which seems to be automated), and will hopefully get some more info.
In the meantime, I wondered if perhaps I misunderstood the scopes. It was a complex process and I don't remember if ../auth/documents.currentonly was automatically added to the screen, or if I had to add it at some point. I know it comes from a comment in the code of the add-on:
/**
* #OnlyCurrentDoc
*/
This is explained on https://developers.google.com/apps-script/guides/services/authorization
I'm wondering if the problem is that since my add-on is published, I also need to explicitly add a broader scope: ../auth/documents, which is indeed a scope that requires authorization ("risky"?). My add-on doesn't use other documents than the current one, so that wouldn't make sense to need it. It's how I understood the Google documentation about this.
As an experiment, here's what the screen looks like if I add that scope:
If I add that (and the corresponding one for presentations), I can request another verification (although I am unsure if it's really needed). Do the currentonly scopes also require the broader ones?
Update 2019-12-13
Today, even though I still have no reply to my response to the automated email, I see that my add-on has more than 100 users. That should not have happened according to the email I received, unless something changed. I'm assuming someone resolved the inconsistency on the Google side of things.

Access without Logging in

Im using GWT, GAE to make a web app.
I looked at a bunch of tutorials regarding implementing a login system but most of those tutorials implement it so it's mandatory to login to access the web app. How would I go about making it so that anyone can access the app but if they want to use account specific functionality, they they have the option of signing up for an account.
There are two parts to it.
First, in your client code you check if a user is logged in. If so, you allow access to the "closed" parts of the app. If not, you show a link/button to login and hide tabs/views that are accessible to authorized users.
Second, in your server code you specify which requests do not require authentication and which do require it. This is necessary if a user somehow figures out how to send a request without using your client code.
For example, in my code some requests have checkSession() called at the very beginning. If no authentication object is found for this user in session, this method throws LoginException to the client. If the authentication object is present, the request continues to execute normally and returns requested data to the client.
Further to Andrei's answer, if you want a framework to manage the sessions for you, you can use GWT-Platform, which has an excellent Gatekeeper feature.
I use it for mine and I have a LoggedInGatekeeper class. Simply add #UseGatekeeper(LoggedInGatekeeper.class) to the constructor of each presenter proxy and it checks if the user is logged in. If you want anyone to be able to access that page simply annotate with #NoGatekeeper. Easy!
It takes a bit of setting up but it's a great MVP framework. There are maven archetypes and samples etc.
Hope this helps.

Facebook Javascript SDK security

I'm in the process of using the facebook javascript sdk to provide user login functionality for a website.
What I'd like to do is simply take the logged in user's unique facebook id and then put/fetch data to/from a mysql database using the id to determine what data is available to said user.
However I don't really feel like this is very secure. Whilst I'm not storing anything sensitive like credit-card details etc, I'd obviously prefer it to be as secure as practically possible.
My fear is that with javascript being what is it, someone could fake the facebook id and just pull whatever they wanted.
I'm aware that the php sdk would provide a solid solution to this problem, but i like the javascript one mainly because it's easy to use and I have the basis of it set up (I admit it, I'm lazy).
So, my questions are:
Would this set up be as insecure as I feel it might be?
Is there anything I can do to improve the security of such a system, other than switching to the php sdk?
Thanks!
Facebook Ids are pretty hard to make up (at most a user will only know their own). Depending on what you store in the database (which will not be anything that the user cannot get on their own, unless you ask for extended permissions)
If you are worried about a user trying to get information from the database, add an access token or signed request to each row and us that and facebook id to get data. That will greatly increase security.
EDIT
There are few occasions where you get a signed request from a user:
* A signed_request is passed to Apps on Facebook.com when they are loaded into the Facebook environment
* A signed_request is passed to any app that has registered an Deauthorized Callback in the Developer App whenever a given user removes the app using the App Dashboard
* A signed_request is passed to apps that use the Registration Plugin whenever a user successfully registers with their app
Signed requests will contain a user id only if the use has accepted permissions though, and are not passed again if the user enters the application, and accepts permissions (meaning that the signed request would not contain the ID). Because of this saving an access token may be a better idea. Here is more on the signed request
Also the signed request is in the url (param = "signed_request"). I always parse it through c# but I am sure you can at least get one through javascript
It's pretty easy to spoof the origin using curl. I'd imagine Facebook has another mecanism in place to make this possible. If you inspect their code, it appears that they generate an iframe and pass requests through. If I had to guess, they have setup the requests to only be made from the Facebook domain, and ensure that the iframe can only be embedded in a page that has a white listed domain.

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