I have a couple of http functions in my firebase project, because I prefer to hydrate, validate and update the data on the backend. I would like to use the automatic stackdriver logs, but I need to associate the log events with the authenticated user (the requests are authenticated). Is there any way to add some context to database updates? Or commit the changes in the name of the user (not the service account)?
Firestore triggers don't currently associate any information about the end user (not even if you're using Firebase Authentication and security rules), so you will have to write user information into each document in order to track who performed an action on it. It will not just appear in the environment or context.
If you go this route, I strongly suggest adding security rules that require the user to provide their Firebase Auth UID correctly in a document field, so you can be 100% sure it's correct.
Read this for more details: https://medium.com/firebase-developers/patterns-for-security-with-firebase-per-user-permissions-for-cloud-firestore-be67ee8edc4a
Related
In my app using Firebase as back-end, I wanted to implement a new feature based on Firebase Storage to allow my users to save some files.
Knowing that my app can be accessed only by people who are paying a subscription, I'm already filtering the access to Firestore (used in my project to store user data) via a document that stores if the subscrition is valid or not and this is filtered by the Firestore security rules.
I saw that there is no linkage between Firestore and Storage, so I can't in the Storage security rules read my Firestore documents. So I had the idea to use CustomClaims to add to the Auth token an attribute if the subscription is valid or not.
After tinkering a bit with it, I noticed and checked that it takes up to an hour to client to have a refreshed token. Since my app follow roughtly this workflow:
I don't think that is a good user experience to wait for an hour to have access to a service the user just paid.
Is there something I didn't see ? Is there a way to circumvent this problem ? Is there an other way to have a refresh token than to force the user to logout ?
You can force the ID token to be refreshed with currentUser.getIdToken(true) with the JS SDK. There are similar methods for the other Client SDKs.
See the doc for more details.
I have the file stored in firebase cloud storage. This file will only available for the paid user download.
How to set up security rules to allow the paid user to have read access to that file?
[Updated]
I use the cloud firestore to store user collection
Each user doc contain
uid
email
name
photoUrl
provider
status
stripeCustomerId
purchasedProducts << this is the array of product name
I can verify paid user by looking if the product exist in purchasedProducts array.
However, inside the security rule from Firebase storage, it seem I can't access resource (user collection) in there. Or am I missing something?
Thanks
There is no way to access Cloud Firestore from within the security rules for Firebase Storage.
That means the only ways to currently implement your use-case is to:
include the necessary information in the ID token of the user, as a custom claim, which is then also available in security rules.
include the necessary information about the user (probably their UID) in your security rules
Since the second approach requires that you update your rules for every paying user, it's not very common.
Setting a custom claim can be done through the Firebase Admin SDK, for example from a Cloud Function that triggers when you write their payment information to Cloud Firestore.
Once you set the custom claim it may take up to an hour before it's available on the client, and from there in the security rules. The reason for that is that the claims are included in the ID token, which only auth-refreshes once an hour. If you want to get the updated claims sooner, you can force a refresh of the user's profile on the client.
Another approach you can try is to delete a file right after it was uploaded using the functions.storage.object().onFinalize webhook - this is wehere you can access the database and check if the user was allowed to upload the file.
Even though it may look a bit 'hacky' at the first glance, this is really a precaution measure in the first place - the UI itself would restrict the upload for the "good" users. And for those who messes up with the source code and tries to circumvent the system, onFinalize would do the job.
You can access cloud firestore through the firestorage service security rules:
https://firebase.google.com/docs/storage/security/rules-conditions#enhance_with_firestore
I'm making a little Snapchat clone, and a part of this app I'm trying to build is the ability to add a friend and start a conversation with them. I'm using Firebase to manage my users and I'm a little stuck now trying to figure out what works and why I'm getting problems trying to use some methods or functions.
What I want is this simple line of code to work:
var userByEmail = await _admin.app().auth().getUserByEmail("b#gmail.com");
print(userByEmail.toString());
However this has been giving my some problems, most recently, the following error message:
Unhandled Exception: FirebaseAuthError(auth/invalid-credential): Must initialize app with a cert credential or set your Firebase project ID as the GOOGLE_CLOUD_PROJECT environment variable to call verifyIdToken().
Getting to this point made me want to first ask a question about FirebaseAdmin and Auth before continuing and potentially screwing up my app settings.
Is there a simple way to do what I'm trying to do?
I have a Firebase.instance.initializeApp() in my Main function, do I only ever call that once or should I start initilizeApp in the initState of each Stateful Widget where needed?
What does this error message actually mean?
You are trying to use the Firebase Admin SDK in your Flutter code, which is not possible. The Admin SDKs give full administrative access to your Firebase project, which would be a serious security concern if you allow that in your Flutter app.
If you want to allow certain administrative functionality in your application, you will have to make that functionality available yourself. For example, to look up a user by their email address, there are two common approaches:
Store the minimal information about each user in a cloud-accessible database (such as Firebase's Realtime Database or Cloud Firestore) when each user registers with your app, and then look it up from there.
Wrap the getUserByEmail from the Admin SDK in a custom API that you make for yourself, on a server you control or in Cloud Functions. In that API you validate that the user making the call is authorized to do so, then call Firebase through the API you were trying to use, and return the minimal result back to the caller.
Both of these are feasible and can work to solve a variety of use-cases. But if you've never built backend code before, you might find the first approach easier to get started with.
Also see:
How to get Firebase UID knowing email user?
Flutter get User Data from Firebase
The right way to do what you want is using Firebase auth, authenticating your user and using a collection to store and retrieve users information. That auth information provided by firebase should only be used for authentication and security purposes.
The Firebase admin must have a user logged in to work properly, but its purpose is to provide a more administration environment and should not be used inside a clients app, unless its an admin app.
With all that said, lets go for the rescue:
Authenticate your user (using firebase auth);
After auth, save all the user information you want to share with other user inside its own collection (you will need to create one);
When an authenticated user (this is important) 'request any other users data, you query for the data in the previous created collection.
I want to get User Data from firebase, I need the diplayName of a User. is there any way to get the displayName of a other user with his uid?
There is no way to look up information about another user in Firebase Authentication by using the client-side SDKs of Firebase, as that would be a security risk.
There are two common ways to allow searching the users in a secure way:
Write information about each user to a database (such as Cloud Firestore or the Realtime Database) when they register, and then search the database when needed. That way your code controls what data gets written and thus is searchable.
Firebase has Admin SDKs that run in trusted environments, such as your development machine, a server you control, or Cloud Functions. These SDKs have options to list users, which means you can search them. If you wrap one of the Admin SDKs in a custom API that you build and secure yourself, you can then call that from your Flutter code.
Also see:
React native firebase authentication searching
You can't get the name, or any other details of a user that is not currently signed in using FirebaseAuth.
Instead, you must create a node in your database where you store the name, and any other necessary details by querying the database.
I like to use firebase functions to test firebase rules I defined.
I would like to read/write to realtime database as an existing user to test if the rules work as expected.
I read in getting started page, I can write to realtime database as admin as follow:
admin.database().ref('/messages').push({original: 'some text'});
How can I do the same as a user I have created in firebase instead of as admin?
I believe when you get the Delta Snapshot from the triggered event that the current state of that snapshot is tied to the user. Since the Firebase team is providing you with the server-less environment, they attach the admin as well since it's in a secure location.
So just grabbing the ref from the current snapshot, should give you the ability to test the database rules. Just to clarify, I am talking about the snapshot.ref, and not the snapshot.adminRef.
Here is the reference from their documentation:
Returns a Reference to the Database location where the triggering write occurred. This Reference has the same end-user permissions as the client that did the write. So, if an unauthenticated client did the write, this Reference is unauthenticated. If the client that did the write is authenticated as a certain Firebase Auth user, this Reference is authenticated as that same user.