Troubleshoot simple custom firebase security rules function - google-cloud-firestore

I'm writing a custom cloud function (official documentation) in Firestore security rules that checks to make sure the submitting user is the content owner, per the official documentation.
I'm applying the custom function to the correct path /collection/{documents}/subcollection/{subcollectiondocuments} where every subcollectiondocument has a userId field that's not null. These documents do not have a uid field, but I tried it anyway in 2 and 4 below.
All versions of the custom function below (belongsToRequestor 1,2,3 and 4) generate a "Property resource is undefined on object" error in the Cloud Firestore rules playground simulator.
Do I need to pass something into the custom function, or am I making some other mistake?
rules_version = '2';
service cloud.firestore {
match /databases/{database}/documents {
function belongsToRequestor1() {
return
request.auth.uid == resource.data.userId;
}
function belongsToRequestor2() {
return
request.auth.uid == resource.data.uid;
}
function belongsToRequestor3() {
return
request.auth.uid == request.resource.data.userId;
}
function belongsToRequestor4() {
return
request.auth.uid == request.resource.data.uid;
}
…
match /collection/{documents}/subcollection/{subcollectiondocuments} {
allow update: if
belongsToRequestor1();
// or belongsToRequestor2(); or belongsToRequestor3(); or belongsToRequestor4();
…
} }
I'm not sure how to implement this answer to another question to "…enter the path to an actual document that exists if you want to test your rule that uses its field values." Each document in subcollectiondocuments has an id auto-generated by firebase.
Update: adding database screenshot (with fake data), as requested (properties = collection and reviews == subcollection):
Thanks for any help!

Related

How To Add Firebase Rules To Specific User To read And Write And all other User only read?

I Have Created firebase and flutter app and google is sending me emails saying firebase rules are not good. How do I make those rules better? I want to give permission to login users to read and my account to read and write permission.
I hope that will help you.
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 != null && request.auth.uid == userId;
allow create: if request.auth != null;
}
}
}
This is a correct way you can secure database.
rules_version = '2';
service cloud.firestore {
match /databases/{database}/documents {
// Line below secure whole database so users are not alowed to create any new collections etc.
match /{document=**} {
allow read, write: if false;
}
match /app/{dataId} {
allow read: if true;
allow write: if isAdmin();
}
match /posts/{dataId} {
allow read: if resource.data.isPublic == true || isAdmin();
allow write: if isAdmin();
}
}
}
function isAdmin() {
return request.auth.token.admin == true;
}
Users don't have any .admin variables. You have to assign them using firebase functions. Read about custom claims.

firestore rules, permission errors

Im trying to figure out how the rules in Firestore work, and have stumbled upon a problem I cant quite figure why is failing.
When using the Firestore Rules Playground and do a get request for a document in /apps, I get the following error: "Error running simulation — Error: simulator.rules line [10], column [14]. Null value error."
And from the app im getting: FirebaseError: Missing or insufficient permissions
The location in trying to get: "/apps/0aKQw0MiRzEbrLDvsnI3"
rules_version = '2';
service cloud.firestore {
match /databases/{database}/documents {
match /{document=**} {
allow read, write: if isUserAuthenticated();
}
/* Functions */
function isUserAuthenticated() {
return request.auth.uid != null;
}
}
}
The thing im trying achieve is to allow read access for all document, and only write access if a user is signed in
I have no idea why it's failing on a get request?
If I'm not mistaken the way you added the read condition seems to be incorrect. Perhaps try this and see if it works for you.
match /databases/{database}/documents { match /{document=**} { allow read: if true, write: if request.auth != null && request.auth.uid!=null }

Don't get the simplest FireStore security rule to work as if it would not find my file - though looks like examples

I don't get this running, no matter what I do. I have already removed all rules, nevertheless I get simulated read denied. I habe tried companies/4U4kZKXkr3rHA6B04S5K and /companies/4U4kZKXkr3rHA6B04S5K as location, copy pasted the document id and the collection multiple times, nothing... To me, it looks just like all the running examples, I found
What am I doing wrong?!
UPDATE: I used these rules before, which did not work:
match /databases/{database}/documents {
// the request object contains info about the authentication status of the requesting user
// if the .auth property is not set, the user is not signed in
function isSignedIn() {
return request.auth != null;
}
// return the current users entry in the employees collection
function getEmployeeData() {
return get(/databases/$(database)/documents/employees/$(request.auth.uid)).data
}
// check if the current user has access to specific company
function accessCompany(companyId) {
return isSignedIn() && getEmployeeData()['companyId'] == companyId;
}
// check if the current user has a specific role
function hasRole(role) {
return isSignedIn() && getEmployeeData()[role] == true;
}
// check if the user has any of the given roles (list)
//function hasAnyRole(roles) {
// return isSignedIn() && getRoles().keys().hasAny(roles);
//}
}
match /users/{user} {
// anyone can see a specific users profile data (name, email etc), in a real scenario you might want to make this more granular
allow get: if true;
// noone can query for users
allow list, create: if false;
// users can modify their own data
allow update, delete: if request.auth.uid == user;
}
match /employees/{user} {
// only allow admins to set roles. Of course a user should be able to retrieve its own designated roles
allow get: if request.auth.uid == user || hasRole('admin');
allow list: if hasRole('admin');
allow update: if hasRole('admin');
allow create, delete: if false;
}
match /companies/{document=**} {
allow get, list, create, update, delete: if true;
}
}
By default, no read and write access is allowed to any document. If you want to allow access to a document, you must have at least one rule that matches the query that would allow that access. If you have commented out all your rules, then I would expect no reads or writes to be allowed.
Minimally, adding a rule like this will allow read access to all documents in the companies collection:
match /companies/{id} {
allow read: if true;
}
I suggest reviewing the documentation on security rules to better learn how they work.

Firebase Security rules to restrict access on all paths but one?

Question:
For the different top-level firestore collections below, how to restrict access to all but one of the paths?
We are building a data schema in Firestore to support a chat app for teachers across multiple schools.
The top-level firestore collections include:
/siteAdminUsers
/schools
/schools/{schoolId}/teachers
/schools/{schoolId}/chats
Below is the security rules setup we are trying now - where we check for:
valid user auth
expected value exists in userClaim variable request.auth.token.chatFlatList
However, the read listener for /messages is being blocked.
Error message:
FirebaseError: [code=permission-denied]: Missing or insufficient permissions
service cloud.firestore {
match /databases/{database}/documents {
match /{document=**} {
allow read, write: if false;
}
match /schools/{schoolId}/chats/{discussionId}/messages {
allow write: if false;
allow read: if request.auth != null
&& request.auth.token != null
&& request.auth.token.chatFlatList.val().contains($discussionId);
}
}
Details
We are using cloud functions for all data read/write, so for almost every case we can just block all client access.
The one exception is for the chat discussions, where we need to set a snapshot listener in the mobile client to know when there are new messages.
Sub-collection notes:
At a school, there are discussion sessions for school staff (teachers, admins, etc)
/schools/{schoolId}/chats/{discussionId}
Where each discussion-document contains:
list of participant teacher ids
subcollection for actual messages where each document is an indivual posted message:
/schools/{schoolId}/chats/{discussionId}/messages
User Claim code from Cloud Function
Looking at the cloud function logs, we have verified that the userClaim is being set.
return firebaseAdmin
.auth()
.setCustomUserClaims(
uid, {
chatFlatList: 'id1 id2 id3'
}
);
UPDATE #1
Tried the following variation where rules skip/omit the check on userClaim and auth.token.
However, still same permission error.
service cloud.firestore {
match /databases/{database}/documents {
match /{document=**} {
allow read, write: if false;
}
match /schools/{schoolId}/chats/{discussionId}/messages {
allow write: if false;
allow read: if request.auth != null;
}
}
}
I think the issue here is that you are writing a rule on the collection called messages.
All match statements should point to documents, not collections.
https://firebase.google.com/docs/firestore/security/rules-structure
You should try adding /{document=**} after your path to messages, something like:
match /schools/{schoolId}/chats/{discussionId}/messages/{document=**} {
allow write: if false;
allow read: if request.auth != null;
}
This worked for me if I wanted to read and write all collection but not one collection named "backStage";
rules_version = '2';
service cloud.firestore {
match /databases/{database}/documents {
match /{collection}/{document} {
allow read: if true
allow write: if (collection != "backStage");
}
}
}
Here's a solution (seems to be working), which includes the check on chatFlatList user claim variable (from original question) for a substring :
match /schools/{schoolId}/chats/{discussionId}/messages {
allow write: if false;
allow read: if request.auth != null
&& request.auth.token.chatFlatList.matches(discussionId);
}
Figured this out thanks to:
Firebase storage rules based on custom parameters
Here the post shows there is not any $ notation to access the path var. I recall seeing this in a security rules example code example - maybe it's specific to database tiers?
https://firebase.google.com/docs/reference/security/storage/#string
https://regex-golang.appspot.com/assets/html/index.html
Trying some example inputs here, to get an understanding for how to create the regex's.

Allow read of firestore document, if it does not exist

In Firestore I wan't to allow a read, if the targeted document does not exists. I have tried the following:
service cloud.firestore {
match /databases/{database}/documents {
match /reports/{report} {
allow read: if !exists(/databases/$(database)/documents/reports/{report});
}
}
}
It does not work, the respons is: Missing or insufficient permissions..
In case you're doing this server-side, you might instead query the document's existence using the admin SDK (firestore rules are only applied to the client SDK):
const snapshot = await adminFirestore.doc('reports/non-existent-item').get();
if (!snapshot.exists) {
// handle gracefully
}
This seems to be working.
allow get: if resource == null;