I have a collection of "Users" in Cloud Firestore and I am using Firebase Auth to authenticate my app users as follows:
The user authenticates within the mobile app (for example with Google).
I verify that there is no document within the "Users" collection that corresponds to the UID of the authenticated user.
If the document does not exist in "Users" I use the user's UID to create a new document.
It is my question: Is there a security problem with this model or some other type?
I am confused by Google documentation because it says that the user's UID is unique to the Firebase project but should not be used to authenticate my user to the backend server. It also says that in that case, I should use FirebaseUser.getToken () but that token can change, so it will create a new user in my DB.
So, my second question is: When should you use that token? Give me an example, please.
Thanks for the help.
USER_ID
You can use the google generated user_id for future reference. That will never change for a given user email or authentication type as long as the user is already in the database.
Example:
If the user Signed In with google federated login with user1#example.com then the user record is maintained in the Firebase and USER_ID(Say ABFDe12cdaa2...) will be assigned(You can use this id in URLs to see the user profile etc it is kind of 32 chars long(I am not sure exactly here). Now, If a user tries to sign up again with the same email(user1#example.com) then it pulls the previous record ABFDe12cdaa2.... If you delete a user1#example.com from the firebase database(Firebase maintains its own database of the user for your project, With has a limited number of user properties). Then the user tries to sign in again then the new USER_ID is generated.
Now the TOKEN:
As you USER_ID is public, it can be seen by everyone. It is not used for authentication.
So you need to generate the token( This is longer the user id) to authenticate programmatically with the Firebase. It token is temporary and specific to the user. It will expire in some time ( you can define that time while creating the token). a refresh token is used to get a new token.
I don't have any code examples while writing this answer. I will update with code example,If, I find any.
Hope I clarified some of your questions.
Related
I am making an app, and in that app, users login and I am storing their information; however, I have noticed that I don't have a users' password information after they register. Is it a good idea to store users' password when they register through Firebase? And is there a point where I will need their passwords? I want to make sure before I proceed further. Thanks!
You do not do that.
Use the (awesome, amazing) Firebase authentication system.
Click right here:
on the left, to see all the users - click "Authentication".
You never see / you cannot see their passwords.
You don't handle or touch the passwords at all.
In the Android or iOS app, you get the userid - and that's it.
The answer by #PeterHaddad shows perfectly how to do that.
That's the first and most basic step in any Firebase ios/droid app.
In your data you'll have a "table" called probably "userData/" and that's where you keep all data about the user. (For example, you may store their address, real name, shoe size .. whatever is relevant in your app.)
Note - FBase is so amazing, your users can also connect with other methods (phone, etc). For your reference in the future, that is explained here
You don't need to store the password in the firebase database, after you authenticate the user using createUserWithEmailAndPassword the email and other info will be stored in the authentication console. So you do not need the password in the database, all you need is the userid to connect auth with database.
FirebaseUser user=FirebaseAuth.getInstance().getCurrentUser();
String useruid=user.getUid();
I have authenticated my user using phone authentication, and the user object that is returned has this long string when I call user.getUid() :
dn27dhJK..... (some long string).
If I authenticate this user on some other device (using my phone number etc), will user.getUid() always be the same ?
EDIT: From the documentation: https://firebase.google.com/docs/reference/android/com/google/firebase/auth/FirebaseUser
public abstract String getUid ()
Also: Google Play services Returns a string used to uniquely identify
your user in your Firebase project's user database. Use it when
storing information in Firebase Database or Storage, or even in your
own backend.
This identifier is opaque and does not correspond necessarily to the
user's email address or any other field.
It is unclear if this id remains constant or not.
When you first verify the phone number (or first sign in with a social provider, or call createUser), a user account is created - and thus a new unique UID id created. From that moment on, that user/phone number will remain associated with that account/UID. No matter if they re-verify on the same or a different device.
If you delete the account, a new account+UID will be generated when you use that same phone number next time.
If you're using Firebase Authentication in your project:
Remember
Firebase will generate a single unique key(i.e. UID) on registration of a/c whether using Email/Phone number.
This key remain associated to that a/c untill a/c is exist in firebase authentication list.
If your app is uninstalled on phone & then a/c is open in another then we can fetch that key from Firebase cloud auth. service.( UID remain safe).
This Uid is created when the user signs up and is linked to the phone number that you used. When you sign in you will get the same uid. But if you try to sign up again with the same phone number, it will basically give an error saying this phone number is already signed up.Hope that explains!
I am new to the Firebase database.I have learned that push methods generate a unique key in Firebase database.My question is After the authentication, how to set the user_id as the key? so every time User logged in. User can manipulate its own data .. I have searched a lot but didn't find help. Thanks.
You usually save the user specific data under a node with the $user_id as key. You set write permissions to only that user. When the user first signs up, you create that node on the client side where the user just signed in and then populate with that user's data. So you first define the rule in the Firebase Console for that node ahead of time, create the user db node after first time authentication. From there, the user can only manipulate its own data. Check this doc for more on this: https://firebase.google.com/docs/database/security/user-security
I am currently making an Android app that allows Facebook sign-in and for each user, stores their email address (from Facebook) along with a couple integer variables in my database.
Upon login, I want my app to check if my database contains the email address of the logged on user. If it does, I proceed with the app functionality, if not, I create a new entry in my database for that user, with an email address and the associated integers.
How can I formulate a query or request that searches my database for a given email string? I am not very experienced with Firebase.
Using FirebaseAuth for your Facebook sign-in would give every user a unique id generated by Firebase.
This id is returned to you in the code when login is successful. You could then retrieve the user's email from the returned object.
Assuming you're using Firebase's real time database to store your info, you could check out their official docs here on how to use your DatabaseReference DataSnapshot to query the database
I working for an app that requires google login. I need to access provider_uid, email, display name, first name, last name.
I managed to iterate all google accounts from the device and present them in a list. After the user perform a click on a list item, I access the selected account auth_token via AccountManagerCallback. But I need provier_uid(an example: https://www.google.com/accounts/o8/id?id=Alt....) and the fields enumerated above. I suppose I must perform some request to google server where to query this information (and passing account token key to request), but I didn't find any docs for this(only authentication, authorization - using ClientLogin, OAuth 2.0 and OpenId).
It's my first time when handling google auth(except picassa and yoututbe auth+upload).
I need this to update a database and be able to authenticate the user(which has the option to upload images and do other things on my server).
Thanks,
Alex.
I found a solution to this problem ( Webservice credentials - OpenID/Android AccountManager? - see Igor Zubchenok answer).
Now I send the auth token to my server where I use gdata/gauva jars to getter informations about the account.