Different security rules for different Firestore collections - firebase

I'm currently using Firestore for the first time and trying to understand the security rules a bit. I now my question is really simple and that I could figure out an answer by doing a bit more research but I wanted to be sure that I am doing the right thing, so I thought it would be better to just ask here.
If I had two collections in Firestore one called "A" and the other "B" what would my security rules have to be if I wanted just authenticated users to read, write, update, delete... in A and everyone to read in B but just authenticated users to write, update, delete... in B.
Edit:
Here are the current rules they apply the rules for B to all collections:
service cloud.firestore {
match /databases/{database}/documents {
match /{document=**} {
allow read: if true;
allow write: if request.auth.uid != null;
}
}
}

If you look at the documentation on authentication in security rules, you will find these rules:
service cloud.firestore {
match /databases/{database}/documents {
// Allow the user to access documents in the "cities" collection
// only if they are authenticated.
match /cities/{city} {
allow read, write: if request.auth.uid != null;
}
}
}
Modified for your use-case, that'd be something like:
service cloud.firestore {
match /databases/{database}/documents {
match /A/{id} {
allow read, write: if request.auth.uid != null;
}
match /B/{id} {
allow read;
allow write: if request.auth.uid != null;
}
}
}

Related

How to prevent Firestore to create root collection automatically during addDocument?

In Firestore, I have a collection "form1"
In my client app, when I create a document in a collection that doesn't exist, say "form2"
db.collection("form2").addDocument(data: data)...
I see from Firestore console, "form2" was created automatically to hold the new document. I hope addDocument() would return error in this case.
How to do it with Security rules? or with other method?
Here is my current Secuirty rules:
rules_version = '12';
service cloud.firestore {
match /databases/{database}/documents {
match /{document=**} { // only logged-in user can access
allow read, write: if request.auth.uid != null;
}
}
}
Why can't following work? (insufficient permission even if the root collection exist)
service cloud.firestore {
match /databases/{database}/documents {
match /{collection} {
allow read, write: if false;
}
match /{collection}/{document} {
allow read, write: if exists(/databases/$(database)/documents/$(collection));
}
}
}
You can disallow writing to all documents as default and then write rules to allow the only ones you decide:
service cloud.firestore {
match /databases/{database}/documents {
match /{document=**} {
allow read, write: if false;// This disallow write and read for all documents
}
match /admin_/** {
allow read, write: if request.auth.token.admin == true;
}
}
}
This will not allow writes to any collection or document except to admin

Why my firestore rules is not validating writes?

I have a collection structure like this.
products {
123456 : {
stock_qty : (Number)
}
}
I want to validate stock quantity to be positive. I have applied following firebase security rule.
service cloud.firestore {
match /databases/{database}/documents {
match /{document=**} {
allow read: if request.auth.uid != null;
allow write: if request.auth.uid != null;
}
match /products/{document=**}{
allow write: if request.resource.data.stock_qty > 0;
}
}
}
But Still I am able to add products with negative stock_qty.
what I am doing wrong here?
You need to remove this part of your rules:
match /{document=**} {
allow read: if request.auth.uid != null;
allow write: if request.auth.uid != null;
}
This allows all authenticated users to read and write your entire database, regardless of any other rules you have defined.
If any rule gives access to a document, another rule cannot revoke that access.
If you have other queries for other collections that must be protected, you will need rules for those other collections as well.

How to use wildcards in firebase security rules

I'm trying to use a wildcard in my firebase security rules but it's not working like the online documentation describes.
I want to return the entire itineraryList collection but the security rules aren't working.
match /itinerary/{userId=**}/itineraryList/{doc} {
allow read: if request.auth.uid == userId;
allow write: if request.auth.uid == userId;
}
What is the correct syntax here to give authenticated users access to the entire list?
Update following your comments:
If you want to give read access to any authenticated user to all documents under the itinerary collection (including sub-collections), do as follows:
service cloud.firestore {
match /databases/{database}/documents {
match /itinerary/{docId=**} {
allow read: if request.auth.uid != null;
}
//possibly add another rule for write
}
}
Initial answer:
This is because by doing {userId=**} you are using the "recursive wildcard syntax", see https://firebase.google.com/docs/firestore/security/rules-structure#recursive_wildcards. It will correspond to the "entire matching path segment".
You should do:
service cloud.firestore {
match /databases/{database}/documents {
match /itinerary/{userId}/itineraryList/{doc} {
allow read: if request.auth.uid == userId;
allow write: if request.auth.uid == userId;
}
}
}
You may also watch this official Firebase video about Firestore security rules, it explains this point, among others: https://www.youtube.com/watch?v=eW5MdE3ZcAw

firebase rules write for auth user but delete only its own data

is there a way to let users only delete their own data? auth users can write to FB and read other users data but only can delete theis own data.
could it be that write rule includes the delete rule?
like:
service cloud.firestore {
match /databases/{database}/documents {
match /{document=**} {
allow read;
allow delete: if request.auth.uid == resource.data.userid;
allow write: if request.auth.uid != null;
}
}
}
Write permission does include delete. This is stated in the documentation.
A read rule can be broken into get and list, while a write rule can be broken into create, update, and delete
So, if you grate write access, you are implicitly granting create, update, and delete. You might want to break them up separately:
service cloud.firestore {
match /databases/{database}/documents {
match /{document=**} {
allow read;
allow delete: if request.auth.uid == resource.data.userid;
allow create, update: if request.auth.uid != null;
}
}
}

How can Firestore check a collection to allow write (rules)

I use a collection called "admin" in Firestore to define which users can write new documents (image below).
At moment, it is controled just by software. I would like to add rules to Firestore. I tried the rule below but it didn't work. What would be the correct rules in that case ?
service cloud.firestore {
match /databases/{database}/documents {
match /{document=**} {
allow read: if request.auth != null;
allow write: if get(/admin/{anyDocument}).data.userId == request.auth.uid;
}
}
}
I'd recommend instead having a users collection with an admin field that can be set to true/false. Then you can do something like:
service cloud.firestore {
match /databases/{database}/documents {
match /{document=**} {
allow read: if request.auth != null;
allow write: if get(/users/${request.auth.uid}).data.admin == true;
}
}
}
As far i know this is not possible with your current database structure. Because the push key is not accessible in firestore rules unless it is with in the admin node.
One way is to save the admin with their uid as key like admin/userID/data...
now you can access it
allow write: if get(/databases/$(database)/documents/admin/$(request.auth.uid)).data.userId == request.auth.uid;;

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