Firestore online rules simulator fails with custom claims - google-cloud-firestore

Using the firestore online security simulation with custom claims results in an error, but it works perfectly when deployed (while actually handling real requests). The error is:
Error: simulator.rules line [5], column [23]. Property admin is undefined on object.
I have confirmed that the user actually have the claim (by the admin SDK and by using the application I'm adding the rules to).
match /{document=**} {
allow write: if request.auth.token.admin;
allow read;
}
Is this expected? Is the simulator broken or am I missing something? Not being able to use the simulator will be hard as I expect to use a few custom claims in my application.

The rules simulator doesn't run with a real user from Firebase Authentication, but runs with the user you define within the simulator itself in the bottom left section of your screenshot.
So you'll need to specify the admin claim in the rules playground by selecting the Custom provider, and then editing the Auth token payload to include a token.admin property.

Related

Flutter App: Firebase Credentials viewable in Source Code (apk / web) = unsecure database? [duplicate]

The Firebase Web-App guide states I should put the given apiKey in my Html to initialize Firebase:
// TODO: Replace with your project's customized code snippet
<script src="https://www.gstatic.com/firebasejs/3.0.2/firebase.js"></script>
<script>
// Initialize Firebase
var config = {
apiKey: '<your-api-key>',
authDomain: '<your-auth-domain>',
databaseURL: '<your-database-url>',
storageBucket: '<your-storage-bucket>'
};
firebase.initializeApp(config);
</script>
By doing so, the apiKey is exposed to every visitor.
What is the purpose of that key and is it really meant to be public?
The apiKey in this configuration snippet just identifies your Firebase project on the Google servers. It is not a security risk for someone to know it. In fact, it is necessary for them to know it, in order for them to interact with your Firebase project. This same configuration data is also included in every iOS and Android app that uses Firebase as its backend.
In that sense it is very similar to the database URL that identifies the back-end database associated with your project in the same snippet: https://<app-id>.firebaseio.com. See this question on why this is not a security risk: How to restrict Firebase data modification?, including the use of Firebase's server side security rules to ensure only authorized users can access the backend services.
If you want to learn how to secure all data access to your Firebase backend services is authorized, read up on the documentation on Firebase security rules. These rules control access to file storage and database access, and are enforced on the Firebase servers. So no matter if it's your code, or somebody else's code that uses you configuration data, it can only do what the security rules allow it to do.
For another explanation of what Firebase uses these values for, and for which of them you can set quotas, see the Firebase documentation on using and managing API keys.
If you'd like to reduce the risk of committing this configuration data to version control, consider using the SDK auto-configuration of Firebase Hosting. While the keys will still end up in the browser in the same format, they won't be hard-coded into your code anymore with that.
Update (May 2021): Thanks to the new feature called Firebase App Check, it is now actually possible to limit access to the backend services in your Firebase project to only those coming from iOS, Android and Web apps that are registered in that specific project.
You'll typically want to combine this with the user authentication based security described above, so that you have another shield against abusive users that do use your app.
By combining App Check with security rules you have both broad protection against abuse, and fine gained control over what data each user can access, while still allowing direct access to the database from your client-side application code.
Building on the answers of prufrofro and Frank van Puffelen here, I put together this setup that doesn't prevent scraping, but can make it slightly harder to use your API key.
Warning: To get your data, even with this method, one can for example simply open the JS console in Chrome and type:
firebase.database().ref("/get/all/the/data").once("value", function (data) {
console.log(data.val());
});
Only the database security rules can protect your data.
Nevertheless, I restricted my production API key use to my domain name like this:
https://console.developers.google.com/apis
Select your Firebase project
Credentials
Under API keys, pick your Browser key. It should look like this: "Browser key (auto created by Google Service)"
In "Accept requests from these
HTTP referrers (web sites)", add the URL of your app (exemple: projectname.firebaseapp.com/* )
Now the app will only work on this specific domain name. So I created another API Key that will be private for localhost developement.
Click Create credentials > API Key
By default, as mentioned by Emmanuel Campos, Firebase only whitelists localhost and your Firebase hosting domain.
In order to make sure I don't publish the wrong API key by mistake, I use one of the following methods to automatically use the more restricted one in production.
Setup for Create-React-App
In /env.development:
REACT_APP_API_KEY=###dev-key###
In /env.production:
REACT_APP_API_KEY=###public-key###
In /src/index.js
const firebaseConfig = {
apiKey: process.env.REACT_APP_API_KEY,
// ...
};
I am not convinced to expose security/config keys to client. I would not call it secure, not because some one can steal all private information from first day, because someone can make excessive request, and drain your quota and make you owe to Google a lot of money.
You need to think about many concepts from restricting people not to access where they are not supposed to be, DOS attacks etc.
I would more prefer the client first will hit to your web server, there you put what ever first hand firewall, captcha , cloudflare, custom security in between the client and server, or between server and firebase and you are good to go. At least you can first stop suspect activity before it reaches to firebase. You will have much more flexibility.
I only see one good usage scenario for using client based config for internal usages. For example, you have internal domain, and you are pretty sure outsiders cannot access there, so you can setup environment like browser -> firebase type.
The API key exposure creates a vulnerability when user/password sign up is enabled. There is an open API endpoint that takes the API key and allows anyone to create a new user account. They then can use this new account to log in to your Firebase Auth protected app or use the SDK to auth with user/pass and run queries.
I've reported this to Google but they say it's working as intended.
If you can't disable user/password accounts you should do the following:
Create a cloud function to auto disable new users onCreate and create a new DB entry to manage their access.
Ex: MyUsers/{userId}/Access: 0
exports.addUser = functions.auth.user().onCreate(onAddUser);
exports.deleteUser = functions.auth.user().onDelete(onDeleteUser);
Update your rules to only allow reads for users with access > 1.
On the off chance the listener function doesn't disable the account fast enough then the read rules will prevent them from reading any data.
I believe once database rules are written accurately, it will be enough to protect your data. Moreover, there are guidelines that one can follow to structure your database accordingly. For example, making a UID node under users, and putting all under information under it. After that, you will need to implement a simple database rule as below
"rules": {
"users": {
"$uid": {
".read": "auth != null && auth.uid == $uid",
".write": "auth != null && auth.uid == $uid"
}
}
}
}
No other user will be able to read other users' data, moreover, domain policy will restrict requests coming from other domains.
One can read more about it on
Firebase Security rules
While the original question was answered (that the api key can be exposed - the protection of the data must be set from the DB rulles), I was also looking for a solution to restrict the access to specific parts of the DB.
So after reading this and some personal research about the possibilities, I came up with a slightly different approach to restrict data usage for unauthorised users:
I save my users in my DB too, under the same uid (and save the profile data in there). So i just set the db rules like this:
".read": "auth != null && root.child('/userdata/'+auth.uid+'/userRole').exists()",
".write": "auth != null && root.child('/userdata/'+auth.uid+'/userRole').exists()"
This way only a previous saved user can add new users in the DB so there is no way anyone without an account can do operations on DB.
Also adding new users is posible only if the user has a special role and edit only by admin or by that user itself (something like this):
"userdata": {
"$userId": {
".write": "$userId === auth.uid || root.child('/userdata/'+auth.uid+'/userRole').val() === 'superadmin'",
...
EXPOSURE OF API KEYS ISN'T A SECURITY RISK BUT ANYONE CAN PUT YOUR CREDENTIALS ON THEIR SITE.
Open api keys leads to attacks that can use a lot resources at firebase that will definitely cost your hard money.
You can always restrict you firebase project keys to domains / IP's.
https://console.cloud.google.com/apis/credentials/key
select your project Id and key and restrict it to Your Android/iOs/web App.
It is oky to include them, and special care is required only for Firebase ML or when using Firebase Authentication
API keys for Firebase are different from typical API keys:
Unlike how API keys are typically used, API keys for Firebase services are not used to control access to backend resources; that can only be done with Firebase Security Rules. Usually, you need to fastidiously guard API keys (for example, by using a vault service or setting the keys as environment variables); however, API keys for Firebase services are ok to include in code or checked-in config files.
Although API keys for Firebase services are safe to include in code, there are a few specific cases when you should enforce limits for your API key; for example, if you're using Firebase ML or using Firebase Authentication with the email/password sign-in method. Learn more about these cases later on this page.
For more informations, check the offical docs
I am making a blog website on github pages. I got an idea to embbed comments in the end of every blog page. I understand how firebase get and gives you data.
I have tested many times with project and even using console. I am totally disagree the saying vlit is vulnerable.
Believe me there is no issue of showing your api key publically if you have followed privacy steps recommend by firebase.
Go to https://console.developers.google.com/apis
and perfrom a security steup.
You should not expose this info. in public, specially api keys.
It may lead to a privacy leak.
Before making the website public you should hide it. You can do it in 2 or more ways
Complex coding/hiding
Simply put firebase SDK codes at bottom of your website or app thus firebase automatically does all works. you don't need to put API keys anywhere

was working well but FirebaseException ([cloud_firestore/permission-denied] The caller does not have permission to execute the specified operation.)

I have been working on the Flutter app with firebase and the app was working well but today when I trying to retrieve the data from using snapshot I got this exception.
FirebaseException ([cloud_firestore/permission-denied] The caller does not have permission to execute the specified operation.)
is there any update on firebase i have to do or what ?
When you create a project and set Firestore access it test mode, it sets the database up to allow public access for only a month. If this suddenly happened without a change on your side, it could be that your security rules expired.
Now would be a good moment to implement proper security rules for your data, as leaving all data publicly accessible is a recipe for future problems.
So learn how to secure the data, have a look at the documentation on security rules, this more technical documentation, and also see:
Firestore Permission Denied in Android
Email: [Firebase] Client access to your Cloud Firestore database expiring in X day(s)

Issues capacitor-native-biometric cannot retreive credentials

Anyone used epicshaggy / capacitor-native-biometric plugin and have been able to make it work. I have just been able to trigger the NativeBiometric.verifyIdentity( function and make it recognize my biometrics, but that's about it.
I've crawled the internet and haven't found a complete example of how to use it. To summarize, i just want to understand how can i use biometrics to login a user. How do i make my server uniquely identify a user and provides login token.
According to the CapacitorJs docs, and epicshaggy/capacitor-native-biometric, the correct way to work with user credentials is with the provided methods:
NativeBiometric.setCredentials()
NativeBiometric.getCredentials()
NativeBiometric.deleteCredentials()
These methods
Securely stores user's credentials in Keychain (iOS) or encypts them using Keystore (Android)
These methods are also only available on native devices, hence "method not implemented" when attempting to run in a browser, and must be behind Capacitor.isNativePlatform().
Providing an updated answer because this is still a top result when trying to implement biometrics with CapacitorJs
did you found any solution to this so far? I think your own problem is how to recognize a user? there is actually how I used to do this in react native. First of. you need to have some kind of extra "local storage key" that stored values or user credentials when they log in through the inputs. keep in mind that you are not clearing the "key" even if the user "log out" of the app. so in that case. before they could be able to use biometrics users need to sign in the proper way with the inputs so you could save their credentials like email or any unique values or whatever to use later.
Now, my problem is all the functions are not even working for me ah. it keeps saying "method not implemented"

Firebase storage bucket grants access to some countries only but not others

I have a Firebase Storage bucket located in australia-southeast1. When a user creates an image with my app, that's where the file goes.
Then the image is supposed to be shareable through a download link obtained with the getDownloadUrl() function (so a valid public link with token is generated).
However, when I share that link, people from Australia, Asia and US could access it. But users from EU, Canada, North Africa, etc. couldn't. See an example here.
My guess is that this is because of my bucket's default location. But, I am puzzled since the documentation does not mention any geographic restrictions of this kind and I have not set any specific limitation. It is not even a matter of speed of access, it is just simple access.
Shall I create multiple buckets in multiple locations and duplicate all the images in all buckets to ensure access independently of the user's location?
Edit: Details of debugging attempts
Those who can't access only see a white screen.
I tried to replicate the issue using VPNs of those countries, and checking the inspector, the console says nothing and for the network part, the GET request gives a '200 Connection established' status but 0 Byte transferred.
Then I went on and tried to do the GET request from within my app to
display the image in it. This time, I got in the console a
'Cross-Origin Request Blocked...(Reason: CORS header
'Access-Control-Allow-Origin' missing)' message and still the same
status in the network tab. The app is able to successfully open the
image on VPNs of locations that can view it.
Also, I already checked the CORS configuration in Google Cloud and they look fine and allow
my app's domain to access to the bucket. I even tried to allow any
domain (by setting the origin parameter of the CORS to "*"), just to
see what will happen, but the behaviour remains the same (I don't see
why it would work for some and not for others anyway).
This is usually not an expected behaviour. One reason for this may be the CORS configuration is not properly set. As an initial troubleshooting step I would recommend you to configure it as stated here and in a more detailed manner in this document.
If the above doesn’t help then you may require to raise a support ticket with Google Cloud Platform Support to investigate the issue in detail and find a root cause. If you don’t have a valid support package you may raise a Free Firebase Support ticket.

Read Firebase rules without authentification

I found a previous question very similar to mine, however the other developper needed to write to Firebase and I don’t, hence this near duplicate question:
I have a very simple database with about 150 documents and the users don’t need to authenticate to use my app. Authentication just don’t make sense for what the app does and users only read the database, they don’t write.
My current rules are read allow only which of course triggers the Firebase rule warning daily.
1) Is there a way to set rules similar to “only requests coming from my app can access it”. Given that the app is linked to firebase one would think it’s possible?
2) If I must use authentification, is there a way that I can do this behind the scenes so that the user is unaware of that? Maybe by using a UUID to identify a user and no password or something like that. I want to avoid showing a log in screen at all cost. Think of it as asking to log in to check gas prices...
** This is an iOS app
No, it's not possible.
You can use anonymous authentication to create a user account without requiring a sign-in.