Angularfire - Get email by uid? #askfirebase - firebase

I have an Ionic application using Firebase so I opted to use Angularfire. Currently running Angularfire4. In my application I store the uid and I want to get email related with that uid. I use the email/password login provided by firebase. How can I translate the uid to an email?
The only method found is when using nodejs.

The only data that is exposed in the client-side Authentication SDKs is the profile of the currently authenticated user.
There is no way to look up user data for a UID with the Firebase Authentication client-side SDKs. While admittedly convenient, it would make leaking user-data way too easy.
The only way to look up user data by UID is using the Admin SDK that you found. The idea is that you run those in a trusted environment (e.g. a server you control, or Cloud Functions) and selectively expose the user data that your app needs.

Related

Firebase Firestore integrate chat using existing backend for user data

I develop an iOS application and I'm using Node & Postgres for handling user data and authentication. I would like to add a chat feature to my app and I chose Firestore for this.
My question is how should I link the existing user data with a Firebase collection of users without re-implementing the authentication part from the ground up. Right now the authentication is based on JWTs with access and refresh tokens.
In order to link my existing users, I can add the userId already present in my database to the users collection that I will create in Firestore, but I need some kind of authentication to ensure security.
While the token for Firebase is also a JWT, it will probably have to be separate from your existing JWT, as it contains Firebase-specific information (such as the project ID), and they're signed with different keys.
After you authenticate the user with your own backend, mint a custom token for Firebase authentication with the information you want to use in Firebase/Firestore and security rules, pass that to the client, and sign them in to Firebase with it.

Flutter Firebase, logout other user than me

In my Flutter management application, I would like to disconnect a user other than the one I am logged in with.
I use Firebase as my database, and use email and a password to log in. I don't use a token
I know that in order to disconnect the user I am currently logged in with, it has to be done like this:
FirebaseAuth.instance.signOut();
I can't figure out how to disconnect another user.
In the Firebase client-side SDKs, you can only sign out the currently signed in user. There is no way to sign out a user on another device.
If you want to add user management functionality to your client-side application, you'll want to use a combination of the client-side SDK and a server-side Admin SDK to build this functionality:
Use the Admin SDK in a trusted environment (such as a server you control, or Cloud Functions) to implement the user management functionality.
Create an endpoint that clients can call that exposes this functionality, for example as a callable Cloud Function.
In that endpoint be sure to check whether the user is authorized, for example by checking their ID token to see if it has a certain UID or custom claim.
Call the custom endpoint from your client-side code.

How to authenticate user to Firestore Go SDK?

I'm trying to use the Firestore Go SDK from a client application. This looks like a client-side SDK, based on the functions, but that might be my first error?
I'm struggling to authenticate the user to Firestore. I've already logged them in using the REST API for Firebase Auth. This returns me an ID token, refresh token, etc. How do I use this with the Firestore SDK?
The docs suggest I need to call firestore.NewClient(<context>, <project-id>, <option>). For the latter argument, I've tried option.WithCredentialsJSON(...) passing a JWT-decoded ID token. I've also tried passing the raw refresh token. In both cases, the SDK complains about what I'm passing.
How can I authenticate the user based on the tokens I've obtained?
The Go SDK for Firestore is meant to be used in a trusted environment, such as your development machine, a server you control, or Cloud Functions. It doesn't have a way to sign the user of the application in, but instead authenticates itself with the server with administrative credentials, which you'll don't want to have on non-trusted devices.
option.WithCredentialsJSON accepts not JWT token, but Google Application Default Credentials.
Other option is to provide path to the file with Google Application Default Credentials using environment variable GOOGLE_APPLICATION_CREDENTIALS since firebase sdk is a part of the cloud.google.com/go sdk.
Check out the examples (also with other options).
https://cloud.google.com/docs/authentication/production#auth-cloud-implicit-go
https://godoc.org/cloud.google.com/go#example-package--ApplicationDefaultCredentials

How to get access to the firebase Authentication part

In my app I've 2 login methods(google&facebook) and all the users appear in the Authentication part inside my firebase project, and I haven't list/collection of my users in my database.
I want to display in my app list of users with some personal data.
My question is how do i get access to the users from the Authentication part(to get all the users for example)?
Is it good approach that the users appear only in the Authentication and not inside my database?
You can't list user accounts with the Firebase Authentication client SDK. You can only do that with the Firebase Admin SDK on a backend you control.
If you think it's OK for your users to be able to know all other users, then you should store that information in your database to make it queryable directly from the client, or create some sort of API endpoint where you can invoke the Admin SDK from your app.

How can I create a firebase user from the node.js client

How can I create a firebase user from the node.js client? I see that there is a simple-login but that looks to be used from the web browser. I would like to authenticate with my firebase secret and then call the createuser api somehow.
The way my system is built the clients only send requests to the backend for processing. This way I have a log of every action taken by every user and I can guarantee that each alteration is applied to my other databases as well before it makes it into firebase. Also I do not want users to be able to create other users. Firebase is just a workqueue for me mostly but I am also using the simple login to verify the user then swapping them over to a login token afterwards to get the ability to check custom permissions in the auth on security rules.

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