In short: In GCP credentials can be restricted with application restriction and with API restriction, but Identity Toolkit API cannot be restricted on Expo mobile application.
-In web both restrictions work
-On android/iOS API restriction works but (as I have tested, correct me if I'm wrong) application restrictions does not
Now if using email/password authentication there is an issue.
There is a huge insecurity here as if anyone gets to know your API key (you define in initializeApp and so you connect to Firebase with and so use with Identity Toolkit API).
They can only by knowing that key call Firebase Auth REST API "Sign up with email / password" from anywhere and create users for your project!!
Am I wrong, missing something or can this be prevented somehow?
Things you can do to prevent this:
In "GCP>credentials>Identity Toolkit API" you can lower "Queries per minute" and "Queries per minute per user"
You can in "Firebase>Authentiction>Sign-in method>Manage sign-up quota" lower the quota from same IP address to minium (but does this help in case of android/iOS application?)
But there is no completely secure solution unless you can application restrict your API key as far as I know.
I got the following answer from Firebase support and since there has not been answers I will add this as correct answer for anyone looking solution for same thing or seeing this question.
First of all, I would like to thank you for choosing Firebase to
implement your application. I know that these kinds of situations
could be frustrating, let's work together to provide the best solution
for you.
I have checked your case and I would recommend that you reinforce your
Security Rules, because this is not a security risk, as long as you
secure access to the data within your project correctly for your
requirements, as it is mentioned in this external entry.
We don’t have a way to know the origin of those emails, even if they
were created by real users through your app, but if you identify fake
accounts you can use Cloud Functions to delete all emails registered
with that pattern using Auth triggers. Alternatively, you can delete
the accounts after an established time without activity using Schedule
Functions.
Additionally, if you don’t want to have users on your application, you
would probably need to use the Admin SDK and authenticate the
application by service account instead.
Related
Could someone please explain to me why a bad actor could not create the following disruption for potential new users to my app?
The bad actor:
Obtains a list of emails from the dark web or some other nefarious source.
Acquires my Firebase keys by inspecting my app javascript -- yes my app is minified, but it would still be possible.
inserts malicious javascript code into my app sources on their local browser. The malicious code uses the Firebase sdk and my app keys to create accounts for each email address.
While there is no possibility that the bad actor could gain access to validated accounts;
nevertheless, creating these accounts would generate unsolicited email verification requests to the owners of the emails and it would also interfere with a smooth account-creation experience for those users when they actually do want to signup.
Am I missing something here?
firebaser here
As Dharmaraj also commented: the Firebase configuration that you include in your app is used to identity the project that the code should connect to, and is not any kind of security mechanism on its own. Read more on this in Is it safe to expose Firebase apiKey to the public?
You already in your question noted that creating a flurry of accounts doesn't put user data at risk, which is indeed also correct. Creating an account in your project does not grant the user any access to other user accounts or data in your project yet. If you use one of Firebase's backend services, you should make sure that your security rules for that service don't do this either.
The final piece of the puzzle is that Firebase has many (intentionally undocumented or under-documented) safe guards in place against abuse, such as various types of rate limits and quotas.
Oh, and I'd recommend using the local emulators for most of your testing, as that'll be faster, doesn't risk accidentally racking up charges due to a quick coding mistake, and (most relevant here) doesn't have the rate limits in place that are affecting your e2e test.
I am trying to create a REST API (via Firebase cloud functions) and release it to my clients to allow them creating their mobile apps. The mobile apps they will be creating are used by public users. However, users are not supposed to deal with our APIs and thus authentication. So I don't need end user authentication. It's up to our clients (app makers) to use a "client id" and an "api key".
Based on what I have researched, Firebase Admin SDK might not be a good solution for this end since we're concerned about client level authentication.
I am looking for a standard solution to generate api-keys for the 3rd party clients. This key generation is not a manual process but rather a service that clients will use to obtain a key. Something like google map api for 3rd party developers. We want to keep track of whitelisted clients without needing their app users to deal with authentication.
I'd appreciate suggestions and guidelines to find the best solution for our REST APIs.
The first solution that comes to my mind is thew new Firebas App Check. It would restrict any access beside the Apps and Web pages you have whitelisted for your project. I don't know if that is possible in your usecase (how the cooperation with the other apps look like) but I would deffinitely try this first.
So I have an app where I have enabled google authentication in my firebase project. 25 people I know were authenticated. When I logged in the backend I saw atleast some 80 entries with some weird sounding email addresses which should not be there. I had to delete all the entries manually, known and unknown ones (didn't needed any after sucessful testing). Now that I want to go live, I am really concerned as to how unknown entires entered my firebase authentication records?
This has recently happened 'again' to another new app/project of mine. This time I disabled that unknown email address and took a screenshot (attached).
I really really need to know and understand how safe is data on firestore. If someone can manage to 'hack' the Authentication part and add thir email to Authenticated list of users they may also be able to penetrate the database somehow in future. Please help me in understanding what is happening?
While researching on this, I could only find this similar question but the answer was just not enough explanation for me.
Unknown user in my firebase user authentication (Flutter/firebase)
firebaser here
Since the configuration data for your project is embedded in the application that you send to your users, any user can take that configuration data and then start calling the API with it. This is not a security risk, as long as you secure access to the data within your project correctly for your requirements.
See Is it safe to expose Firebase apiKey to the public?
What it means to correctly secure access to your data is hard to answer, as it depends completely on your use-case.
For example: the content-owner only access security rules allow a user to enter data in the database, and then they can access the data they entered. With these rules there's no risk if anyone uses the API (and not your app) to do the same. The security rules will ensure they only can access data they're authorized for, no matter what the source is the API calls is.
It may be related to the pre-launch report.
https://support.google.com/googleplay/android-developer/answer/9842757?visit_id=637478112313064713-650300184&rd=1#signin
Step 1: Provide test account credentials if your app has a sign-in screen
If your app has a sign-in screen and you want the crawler to test the sign-in process or the content behind it, you need to provide account credentials. Note: You do not need to provide credentials if your app supports 'Sign in with Google', which enables the crawler to log in automatically.
So I guess it is safe.
The user willwhiteapple#gmail.com is the apple testing when your application is in the process of validation from apple before deploy to TestFlight .
I have successfully deployed a Google Cloud Endpoints Developer Portal for my API running on Endpoints. I would like to provide access to testing to people outside my organisation that are not using GCP in their projects.
Login to the portal works correctly if I enable the Service Consumer role for these people (on per-email basis). However, when they open it for the first time, they are being asked to grant some extra permissions to the portal:
This form can create totally unnecessary security concerns. Does anyone know, why is it needed?
I only would like my clients to be able to test my API using a GUI, before they could start connecting their projects (not necessary on GCP) to mine. This seems to be a valid use case for me, however I might be misunderstanding some basic concepts.
Or should I submit a feature request to Google about a new role that only enables the access to the portal, and nothing else, so no such forms are shown?
Since Endpoints APIs must be explicitly shared with customers, the portal needs to verify that the logged-in user has permission to view that Endpoints API. So the short answer is that these scopes are being requested primarily so the portal can check the user's access to this API.
Longer answer is that we (the Endpoints team) are looking into if it's possible to build narrower OAuth scopes that would correspond to the access checks we perform. We agree that it's unnecessarily broad of an access request and are hoping to improve this in the future. Thanks for your comment!
I created a Actions on Google app with the Actions SDK. For this i used as said before the Actions SDK, firebase function for the fulfillment and firestore for storing data. All works fine.
Now i want to implement account linking to provide user specific information. I start to read the full documentation for account linking with the refers to integrate a Oauth 2.0 Server and soon. That is my first time i working with account linking and Oauth servers and now i'm totally confused. I don't understand where my auth server have to sit, how to setup it and what parameters it have to process. After reading more and searching for results i found that firebase provide Account authentication. Is it right that this firebase product is similar a Oauth server?
My next big problem is how to enabling account linking in my Actions app. In the Actions on Google documentation i found a topic how to expand the Action Package for account linking. My problem is to unterstand which information the probiertes need.
So summary, if the firebase authentication is really a Oauth server what i need to do that my app and firebase authentication works together.
Maybe everyone knows a good website for understanding the process of account linking and how it can be implemented.
UPDATE 1:
After getting the first answer for my question i started studying more about account linking and the authentication process.
After this i created following roadmap:
Create an website with a google account sing-in form and host it with firebase hosting
Set up the Oauth2 server
Interact with the linked account. Save account informations in my firestore database
So i started with step one. In the firebase authentication documentation i find a example for a google login form. After modifying and hosting the example i try it. It works fine. After sing in by using the hosted website, my google account linked with my project. I checked this in my google account settings. Also the example response with a lots of data like the profile name, email address and so on. So my question at this point is. Why do i have to set up a OAuth server now? After sign in with the example form i linked my account to my project successful. And so i can start saving the received data in my firebase database and act with them in my Actions app.
UPDATE 2:
Okay . Maybey i have a general problem of understanding the right use of account linking. I try to identify the user who use my action to offer special content when he comes back next time. Or maybe create a question with his name from his google account inside the question. So in my understanding i have to link the users google account with my action and save the account information in a database to identify the use next time. So is account linking for this task the right way?
No, Firebase Authentication is not an OAuth2 server.
Firebase Authentication provides a way for you to manage user accounts for your Firebase-based web or mobile app. With the Auth UI it gives a way for users to log into that account using a variety of means (including their Google account, Facebook account, or phone number). It does not, however, provide components that an OAuth2 server provides.
Most notably, it does not provide any way for a user to log in through another client (like the Google Assistant) to gain authorization for that client. You cannot, with Firebase Authentication, issue a token to the Assistant, nor accept a token from the Assistant and verify if this is a user inside Firebase Authentication.
You need to build these components yourself. Google describes the minimum tasks that it needs to do as part of this authentication. You can use Firebase Authentication as part of this as you build such a server (for example, it is a great way to have people log in to their account and for you to verify that account), and it is reasonable to use a Firebase Database to store user tokens if you go that route, Firebase Functions might be a useful place to implement the token exchange point, and Firebase Hosting would be good to host the login page itself - but you'd need to write code that "puts it all together".
Your auth server can sit anywhere. As I said - you can do it through Firebase Functions, but you don't have it. It just needs to be able to provide some responses through web URLs at HTTPS endpoints.
Once you have done this, you need to configure the endpoints on the actions console and implement a request for account linking in your code or in the action package.
Response to Update 1
After sing in by using the hosted website, my google account linked with my project. I checked this in my google account settings.
From an OAuth perspective - no, the Google Account is not "linked" to your project.
Google has issued a token to you (that is to say, the service that you've written) that gives your service access to certain resources. Those resources include information about a particular user.
This may sound like I'm splitting semantics, but it isn't. It is fundamental to what OAuth is offering and what it means when you get an issue a token. You currently have authorization to do certain things.
Why do i have to set up a OAuth server now? After sign in with the example form i linked my account to my project successful. And so i can start saving the received data in my firebase database and act with them in my Actions app.
You haven't linked your account. You have permission to do certain things.
Furthermore, aside from "that's how they do it", you need to setup an OAuth server because you now need to do the same thing for Google - give them permission to do specific things on your server (like use it). Normally this would be involved with "logging in".
Account Linking is really a fancy term for "logging in". You need a way for users to be able to log into your server. You have an access token, but that is roughly the equivalent of having logged into Google's server.
So why do so many websites, for example, have things like "Log In using Google" or "Log In using Facebook"? Because those sites are willing to trust that if their servers can get permitted to certain information at Google or Facebook, then they can trust you. And you might be willing to accept that when they login to your site (either through the web or through Actions), but the Assistant can't assume that. They need to make sure users actually log into your site - that user's deliberately want to do so and that you deliberately want to let them in.