connecting firebase Realtime database with chrome extension - firebase

I'm beginner and I'm developing a chrome extension that shows data received from my firebase realtime database. It does not need Login, or any personal information.
I'm trying to use REST API. Until now I have been in a test mode so I opened access to data for all. But Google keeps mailing me that I have to change the access rule because it is dangerous.
My present access rule is this:
{
"rules": {
".read": true,
".write": false
}
}
Now, I fetch data from https://<project name>.firebaseio.com/<database name>.json. But if I change the rule, the access will be denied.
So I want to add some key to the url and change access rule according to it so that I can fetch data from the url. For example,
https://<project name>.firebaseio.com/<database name>.json?some_key=<some_key>.
I do not need personal keys so I want only one key just like when we get information from open APIs. For example, when I use weather api, I get my api key from the host and adds the key to url.
Is this possible? If it is, I wonder two things.
the key that I can use (for example, realtime base wep API key)
access rule of realtime database

You can't pass parameters to the Firebase database like this:
https://<project name>.firebaseio.com/<database name>.json?some_key=<some_key>
But if you change the order of the values, it suddenly becomes possible:
https://<project name>.firebaseio.com/<some_key>/<database name>.json
We then change the security rules to only allow access when somebody already knows the secret key:
{
"rules": {
".write": false,
"$some_key": {
".read": true
}
}
}
Now the secret key is part of the path of the data, and only a user that already knows the key can read the data for that key.

Related

Access URL Parameters In Firebase RTDB Security Rules

I want to read data from Firebase:
firebase.database().ref('videos/' + $videoId + '/data' ).once('value')
But in security rules I don't want to make this readable by anyone. Aka I do not want to use:
".read" : true
I want non-authenticated users to be able to read data if they have a special token, that they pass in the url.
firebase.database().ref('videos/' + $videoId + '/data?token=secretToken').once('value')
My video data looks like this:
{
vidoes: {
$videoId: {
data: {
...
}
tokens: {
secretToken: true
}
}
}
I imagine security rules would look something like this:
{
vidoes: {
$videoId: {
data: {
".read": "data.parent().child('tokens/' + auth.urlQuery('token').val() ).exist()"
}
}
}
Is there anyone I can access query string/ url parameters in Firbase security rules? I could use Firebase functions to create an api, but that is an extra step and network request.
Essentially it would behave like a "token" for Firebase storage:
https://firebasestorage.googleapis.com/v0/b/columbus-c4de8.appspot.com/o/richContent%2F1-min.jpeg_-LPgLxBMt1tBR0dDdNzH?alt=media&token=dfe24c92-e0c2-484a-81df-c09a710b3d34
If the token is correct, then user can read the data.
Note: It's technically possible to use tokens for ".write" security rules. See: Using newData on Updates in Firebase Security Rules
This is not possible, and is also not inherently secure. Firebase security rules would not be secure if anyone had a simple password that let them access data. It's pretty easy to reverse engineer a mobile client to extra the password that allows the query.
If you want to grant access to a query to a user, the only secure way to do that is in tandem with Firebase Authentication, which validates the identity of the person performing the request.

Best design pattern for public/sharable routes containing some sensitive data

A manager needs to make the team's schedule live/public. The main challenge I'm running into is my firebase db security rules require users to be logged it in order to read data from it. They sort of look like this:
{
"rules": {
.read:true,
.write:true
}
"profiles":{
".read": true,
".write": true
},
"$clinicId":{
".write":"root.child($clinicId).child('permissions').child('admins').child(auth.uid).val() == true",
".read": "root.child($clinicId).child('permissions').child('members').child(auth.uid).val() == true"
}
}
}
What comes to my head is the following:
1- When the manger publishes the schedule, I would generate a token, add it to my permissions rules, and embed the token in the shared url as a param.
2- Then when an employee tries to access the url, I would use the token to sign in the user into the app.
I have explored claims and tokens in Firebase and I'm not quite sure which one would be the best neither this is a correct approach.
I would appreciate any insights.
Thank you in advance!
So it sounds like you want to make the data public, but harder to access.
Why don't you just include the id of the public doc in the url ? It is already a big-hard-to-guess hash. Which is all you'd be doing.
Additional security might include:
keep public docs separate from private ones, different collections
or use a flag on the doc that you can check the "visibility" of before returning to the client

does the firebase database online editor ignore security rules

I have rules set up that ensure a foreign key like constraint: when I put data at a certain path, the key is validated to exist at another node.
Rule snippet:
"app": {
"freebies": {
"$provider_id": {
".validate": "newData.parent().parent().parent().child('app').child('providers').child($provider_id).val() != null"
}
}
}
If I run a simulation with these params
Write to /app/freebies
width data: {"totally_fake": 1}
This fails, which is CORRECT.
On the other hand, if I just go to the online editor and add a node to the same location with the same data, it writes the DB without errors.
My question is: does the online editor bypass the security rules ?
Yes, it does. The Firebase console, as well as the Admin SDKs, bypass security rules and have "administrative" access to the Realtime Database.

Firebase security child node

I have this DB structure in Firebase:
[bets]
-KTd9VKWJwHd_L6j_oAF
date
team1
etc
-KTdCc7uVmueNtcYzU1m
date
team1
etc
[users]
I'm now trying to write Firebase rules to allow users to only read bets assigned to them. But I ran into problems right away. I have these very basic rules:
{
"rules": {
"bets": {
"$bet": {
".read": true,
".write": true
}
}
}
}
When I try to visit /bets (where I display a list of bets) I get thrown the error:
Error: permission_denied at /bets: Client doesn't have permission to access the desired data.
If I instead place the .read and .write under bets instead of $bet, it works fine. What am I missing?
Firebase evaluates read permission at the location where you attach a listener. You attach a listener to /bets, so it rejects the listener since you don't have read permission on /bets.
If you have read permission to /bets, you also can read everything under it. So this means that you can't use Firebase Database security rules to filter data.
See the section rules are not filters in the Firebase documentation. Or search for Firebase questions mentioning "rules are not filters" here and you'll see this is a common pitfall for developers.

Firebase database authentication with email & password

i am new to firebase. i have set up a firebase realtime database and can read from and write to it if the read and write rules are set to true.
i have a problem with authentication.i have set up authentication for google and email plus password.
my goal is to allow any user to read the data but only one user (myself) can write data after logging in using a single email address and password.
i can successfully read from and write to the database if i login with google (with rules set to: auth != null.)
i can also read from and write to the database using the same rules (auth != null) if i log in with the email address and password.
i don't know how to set it up to only allow write access for the single user logging in with an email address and password.
i have tried including a user node in the rules but i can't get access when using the simulator (see below) and i don't know how to include the uid (which i can get after logging in) when building the reference - this is the reference i currently use (which works with the read and write rules set to true):
DatabaseReference databaseReference = mRootReference.child("Action_helper/1/Action_table_of_contents");
i have not included a users node in my database as i am assuming that is taken care of by firebase authentication.
here is the layout of my data:
i have tried the simulator using various rules options. testing access using these settings in simulator (choosing the Custom provider option):
Auth {"provider" : "firebase", "uid" : "Rp3OgoaABMN3hqTv0aF29ECQRCQ2"}
note: i get the provider and uid from Firebase object after logging in with an email address and password which i have set up in Firebase authentication:
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
if (user != null) {
// User is signed in
userId = user.getUid();
String provider = user.getProviderId();
i would appreciate some help in 1) formulating my rules, 2) if and how i should change my data structure, and finally 3) how to include the uid in the database reference which i'll use to write data to the database.
thanks
There is no users node so, defining in rules would not help. I think the rule that may work would be something like below (assuming 0 and 1 are uid):
{
"rules": {
"Action_helper":{
"$uid":{
//user-based security
".read": "auth != null && $uid === auth.uid",
".write": "auth != null",
}//$uid
}//Action_helper
}// rules
}
Examining above rules by default if we do not define rules then it is false i.e. at Action_helper it is false for both read and write. When it comes to the node uid (where $ denotes wild card) then, we check if the user id of logged in user is same to uid of this node and define rules accordingly.
I highly recommend to go
through the link The key to Firebase security - Google I/O 2016 , it is very helpful, easy to follow, and best explanation I found so far with demo example.
The data layout will depend on your requirement and screens. Although Firebase allows 32 level of nesting it is highly recommended to nest nodes as less as possible. And other important thing to think about the data layout is to keep data as denormalize as possible even if we
have to make copies of fields across the nodes.
To include uid in database reference you can keep on appending each child:
DatabaseReference databaseReference = mRootReference.child("Action_helper).child(uid).child("Action_table_of_contents");
So, here we are referring from root node to child "Action_helper" and going further down to it's child that matches uid and of that uid we are referencing to the child "Action_table_of_contents".
thanks for the help. i managed to get it working (partly) but am not sure that i am doing it correctly. here is my data structure (i have changed the names)- there is one user node (using the authentication uid), and two child nodes which contain the data:
and here are my rules:
essentially it works in the simulator but in code, i am able to log in and read and write. BUT i now have a problem, if i don't log in then the uid passed in the query reference is null, if i put a dummy value as the uid then i can't access the data at all (as the data is under users/the_valid_uid node and the dummy uid does not match the_valid_uid).
so how do i build a database reference without hard coding the valid user's uid? so that i can access the data in the Addiction_items and table_of_contents_items nodes (my aim is to allow anyone to read data in both nodes but to only allow one user (myself) to be able to write to both nodes after logging in with my email address and password?
thanks

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