How to use wildcards in firebase security rules - firebase

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

Related

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.

Different security rules for different Firestore collections

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;
}
}
}

Cloud Firestore Security Rules documentation example

This documentation page: Writing conditions for Cloud Firestore Security Rules, says the following:
Another common pattern is to make sure users can only read and write their own data
And provides this example:
service cloud.firestore {
match /databases/{database}/documents {
// Make sure the uid of the requesting user matches name of the user
// document. The wildcard expression {userId} makes the userId variable
// available in rules.
match /users/{userId} {
allow read, update, delete: if request.auth.uid == userId;
allow create: if request.auth.uid != null;
}
}
}
I don't understand why the create rule is not defined with the same condition as the rest, if request.auth.uid == userId, but instead is defined with if request.auth.uid != null. As I understand it, with this rule any user can create any document inside users, but cannot do anything with it unless it matches his uid. So why allow it at all?
Let's talk about the very basic security rule that could be implemented (with user authentication):
allow read, update, delete: if request.auth.uid != null;
allow create: if request.auth.uid != null;
where any user can delete the documents of another people creation. So to restrict/control it, we implement as shown in the code snippet provided.
service cloud.firestore {
match /databases/{database}/documents {
// Make sure the uid of the requesting user matches name of the user
// document. The wildcard expression {userId} makes the userId variable
// available in rules.
match /users/{userId} {
allow read, update, delete: if request.auth.uid == userId;
allow create: if request.auth.uid != null;
}
}
}
The code snippet is just an example use case that uses different conditions for reference purposes as this is a tutorial/guide, so the Firebase team try to fit as many possible conditions to the code snippet.
You can, of course, do allow create: if request.auth.uid == userId; to strictly restricted to that particular user.
I hope it gives you some idea!

Firestore security rules allow user access to their data

I want to write a rule like this:
service cloud.firestore {
match /databases/{database}/documents {
match /users/{userId}/{document=**} {
allow read, write: if request.auth.uid == userId;
}
}
}
That is, I want to allow all read and write operations to all of a user's data if that user is the authenticated user.
Unfortunately that does not work. I get an error specifying that I don't have permission to access the data.
This code solved the problem:
service cloud.firestore {
match /databases/{database}/documents {
match /users/{userId} {
allow read, write: if request.auth.uid == userId;
match /{document=**} {
allow read, write: if request.auth.uid == userId;
}
}
}
}
I think it's because you need to grant access to /users/{userId}, as well as /users/{userId}/{anyDoc=**}.
From the official documentation:
Another common pattern is to make sure users can only read and write
their own data:
service cloud.firestore {
match /databases/{database}/documents {
// Make sure the uid of the requesting user matches name of the user
// document. The wildcard expression {userId} makes the userId variable
// available in rules.
match /users/{userId} {
allow read, update, delete: if request.auth.uid == userId;
allow create: if request.auth.uid != null;
}
}
}
If your app uses Firebase Authentication, the request.auth variable
contains the authentication information for the client requesting
data.
Please note that this only works if you have made a 'users' table in your database and populated it with users that are known to your application (possibly copied from FireBase's users section Authentication/users in the webconsole).
AfaIcs you cannot refer to the Firestore authenticated users table this way. I found this lack of information very confusing since all examples and Firestore documentation make you believe that you can access the users created through the webconsole this way, invariably resulting in an 'access denied' messages when trying to read from a users table...

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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