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@sararob
Last active April 26, 2022 22:21
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Role-based security in Firebase
/* This shows how you can authenticate users and store user data in Firebase
using Firebase Simple Login with Twitter. The corresponding security rules
are in the security.json file */
// Define Firebase references
var ref = new Firebase("<your-firebase>.firebaseio.com/");
var usersRef = ref.child("users");
var currentUser = null; //we'll use this to see if a user is currently logged in
// Call an 'auth' function when a user clicks a login button (this example uses twitter)
$('#login').on("click", function () {
auth.login('twitter');
});
// Authenticate users and store each user in Firebase by their Twitter UID
var auth = new FirebaseSimpleLogin(ref, function (error, user) {
if (error) {
console.log(error);
} else if (user) {
usersRef.child(user.uid).set({pic: user.thirdPartyUserData.profile_image_url, username: user.username});
currentUser = user;
} else {
//user is logged out
}
});
// When a user adds a message, add the message data to Firebase
$('#message-submit').on('click', function () {
if (currentUser != null) {
var message = $('#msgInput').val();
//Send the message to Firebase
messagesRef.push({user: currentUser.uid, username: currentUser.username, message: message});
} else {
alert('You must login with Twitter to post!');
}
});
{
"rules": {
".read": true,
"messages": {
"$message": {
".write": "auth.uid != null && auth.uid === newData.child('user').val()",
".validate": "newData.child('message').val() != ''"
}
},
"users": {
"$user": {
".write": "auth.uid === $user"
}
}
}
}
@tommybananas
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Shouldn't root.child($room + '/users/' + auth.uid) be something like root.child('rooms/' + $room + '/users/' + auth.uid)?

@jdsingh
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jdsingh commented Jul 25, 2015

@sararob Logged in user can change the role-value at /users/$user ?

Isn't this should be changeable by admin only ?

@AWolf81
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AWolf81 commented Dec 29, 2015

@jdsingh Yes, I think you're right. An authenticated malicious user can change his own role to anything he likes in the browser console. With ref.child('users').child('own-uid').update({'role-value': 20}); with var ref= new Firebase('https://<app>.firebaseio.com');

The user can also look for the available roles with ref.child('users').once('value', function(snapshot) { console.log(snapshot.val()); }

I also think that should be restricted and that's possible if you're putting the user roles in a top level document. Then you can add a write rule only for admin users to edit that document.

I'm learning Firebase at the moment. I'll check this with my current demo and come back once I've got it working.

@hounvs
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hounvs commented Jan 27, 2016

@AWolf81 Any progress? I'm just now learning firebase and am looking for some means of defining/assigning roles securely. I'm not sure of the proper way to organize the database

@Andersos
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Would be nice to address the problem of users being able to change their own role.

@Andersos
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I ended up trying this. Not sure how well it will work

type User {
  name: String,
  email:  String,
  isMember: Boolean,
}

type Role {
  isAdmin: Boolean
}

path /users/{uid} is User {
  read() { isCurrentUser(uid) || isAdmin(uid) }
  write() { isCurrentUser(uid) || isAdmin(uid) }
  validate() { this.isMember === false || isAdmin(uid) }
}

path /roles/{uid} is Role {
  read() { isAdmin(uid) }
  write() { isAdmin(uid) }
}

isCurrentUser(uid) { auth != null && auth.uid == uid }
isAdmin(uid) { auth != null && root.roles.uid.isAdmin.val() }

@Andersos
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@lazabogdan
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@Andersos if you don't mind, what is that code you used in your previous comment? Looks interesting

@curlybracketsco
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I just wrote up some thoughts on what I think is a promising solution to admin / moderator roles from the Firechat app (written by the Firebase devs) - http://curlybrackets.co/blog/2016/03/07/implementing-roles-in-firebase/

@bruno2ms
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@lazabogdan if it still matter, that code was written in Bolt.

Accordingly to Firebase "Bolt is a high level modeling and security language that lets you easily translate your application’s data structure to the low-level JSON rules needed to secure your data in Firebase."

I`m using it in some projects and its preety good.

Firebase blog post

@sebastianovide
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are you still using it ? It is not clear if it will be maintained after Firebase 3.0

@HerRomero
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I am working on an advanced role based security rules system for an app based on this.

chat_permissions
	chat1
		admins
			user1= true
			user2 = true
		observers
			user3 = true
"chat_permissions": {
      ".read": "auth != null",
      	"$group": {
          ".write": "data.child('admins').hasChild(auth.uid) || !data.child('admins').exists() "
        	// allows to modify users permissions (as well as add or delete users) if user is admin or if there are no admins
        }
    }   

After this you set all security rules based on user permissions

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ghost commented Sep 24, 2017

Why do you want to this ir you have the admin sdk for node?

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