Allow service account access only to a subset of a Firetime Realtime Database - firebase

I need to have some code running on a remote server with access only to a subset of my Firebase Realtime Database.
I figured I was going to be able to create a service account with access to the database, and manage it's more detailed read/write permissions using security rules. This doesn't seem to be the case.
I do not want this service account to have any other access to my Firebase project.
Here is an example of what I thought my security rules would roughly look like:
{
"rules": {
"my_restricted_data": {
"X": {
".read": "auth.my_service_account_id === 'X'",
".write": "auth.my_service_account_id === 'X'"
}
}
}
}
Looking at the Google Cloud Platform roles and permissions, I can't seem to separate Firebase Realtime Database access out from other important privileges which I do not want to grant to this service.
Is there any way I can make this work?
I am using the ruby firebase https://github.com/oscardelben/firebase-ruby
Thanks!

The library you're using wraps the Firebase REST API, which in itself can be used to access the database both as an administrative super-user and as a regular authentication user. Unfortunately the two ways to authenticate that the library offers both give administrative access to the database, without a way to specify your own UID. This means that there is no way to limit what your code can do.
I recommend filing a feature request (or a PR) on the repo to add signing in a regular user through the REST API, which will then only be allowed the access that your rules have set for it.

Related

Can Firebase Cloud Functions bypass my app's security? [duplicate]

The Firebase Web-App guide states I should put the given apiKey in my Html to initialize Firebase:
// TODO: Replace with your project's customized code snippet
<script src="https://www.gstatic.com/firebasejs/3.0.2/firebase.js"></script>
<script>
// Initialize Firebase
var config = {
apiKey: '<your-api-key>',
authDomain: '<your-auth-domain>',
databaseURL: '<your-database-url>',
storageBucket: '<your-storage-bucket>'
};
firebase.initializeApp(config);
</script>
By doing so, the apiKey is exposed to every visitor.
What is the purpose of that key and is it really meant to be public?
The apiKey in this configuration snippet just identifies your Firebase project on the Google servers. It is not a security risk for someone to know it. In fact, it is necessary for them to know it, in order for them to interact with your Firebase project. This same configuration data is also included in every iOS and Android app that uses Firebase as its backend.
In that sense it is very similar to the database URL that identifies the back-end database associated with your project in the same snippet: https://<app-id>.firebaseio.com. See this question on why this is not a security risk: How to restrict Firebase data modification?, including the use of Firebase's server side security rules to ensure only authorized users can access the backend services.
If you want to learn how to secure all data access to your Firebase backend services is authorized, read up on the documentation on Firebase security rules. These rules control access to file storage and database access, and are enforced on the Firebase servers. So no matter if it's your code, or somebody else's code that uses you configuration data, it can only do what the security rules allow it to do.
For another explanation of what Firebase uses these values for, and for which of them you can set quotas, see the Firebase documentation on using and managing API keys.
If you'd like to reduce the risk of committing this configuration data to version control, consider using the SDK auto-configuration of Firebase Hosting. While the keys will still end up in the browser in the same format, they won't be hard-coded into your code anymore with that.
Update (May 2021): Thanks to the new feature called Firebase App Check, it is now actually possible to limit access to the backend services in your Firebase project to only those coming from iOS, Android and Web apps that are registered in that specific project.
You'll typically want to combine this with the user authentication based security described above, so that you have another shield against abusive users that do use your app.
By combining App Check with security rules you have both broad protection against abuse, and fine gained control over what data each user can access, while still allowing direct access to the database from your client-side application code.
Building on the answers of prufrofro and Frank van Puffelen here, I put together this setup that doesn't prevent scraping, but can make it slightly harder to use your API key.
Warning: To get your data, even with this method, one can for example simply open the JS console in Chrome and type:
firebase.database().ref("/get/all/the/data").once("value", function (data) {
console.log(data.val());
});
Only the database security rules can protect your data.
Nevertheless, I restricted my production API key use to my domain name like this:
https://console.developers.google.com/apis
Select your Firebase project
Credentials
Under API keys, pick your Browser key. It should look like this: "Browser key (auto created by Google Service)"
In "Accept requests from these
HTTP referrers (web sites)", add the URL of your app (exemple: projectname.firebaseapp.com/* )
Now the app will only work on this specific domain name. So I created another API Key that will be private for localhost developement.
Click Create credentials > API Key
By default, as mentioned by Emmanuel Campos, Firebase only whitelists localhost and your Firebase hosting domain.
In order to make sure I don't publish the wrong API key by mistake, I use one of the following methods to automatically use the more restricted one in production.
Setup for Create-React-App
In /env.development:
REACT_APP_API_KEY=###dev-key###
In /env.production:
REACT_APP_API_KEY=###public-key###
In /src/index.js
const firebaseConfig = {
apiKey: process.env.REACT_APP_API_KEY,
// ...
};
I am not convinced to expose security/config keys to client. I would not call it secure, not because some one can steal all private information from first day, because someone can make excessive request, and drain your quota and make you owe to Google a lot of money.
You need to think about many concepts from restricting people not to access where they are not supposed to be, DOS attacks etc.
I would more prefer the client first will hit to your web server, there you put what ever first hand firewall, captcha , cloudflare, custom security in between the client and server, or between server and firebase and you are good to go. At least you can first stop suspect activity before it reaches to firebase. You will have much more flexibility.
I only see one good usage scenario for using client based config for internal usages. For example, you have internal domain, and you are pretty sure outsiders cannot access there, so you can setup environment like browser -> firebase type.
The API key exposure creates a vulnerability when user/password sign up is enabled. There is an open API endpoint that takes the API key and allows anyone to create a new user account. They then can use this new account to log in to your Firebase Auth protected app or use the SDK to auth with user/pass and run queries.
I've reported this to Google but they say it's working as intended.
If you can't disable user/password accounts you should do the following:
Create a cloud function to auto disable new users onCreate and create a new DB entry to manage their access.
Ex: MyUsers/{userId}/Access: 0
exports.addUser = functions.auth.user().onCreate(onAddUser);
exports.deleteUser = functions.auth.user().onDelete(onDeleteUser);
Update your rules to only allow reads for users with access > 1.
On the off chance the listener function doesn't disable the account fast enough then the read rules will prevent them from reading any data.
I believe once database rules are written accurately, it will be enough to protect your data. Moreover, there are guidelines that one can follow to structure your database accordingly. For example, making a UID node under users, and putting all under information under it. After that, you will need to implement a simple database rule as below
"rules": {
"users": {
"$uid": {
".read": "auth != null && auth.uid == $uid",
".write": "auth != null && auth.uid == $uid"
}
}
}
}
No other user will be able to read other users' data, moreover, domain policy will restrict requests coming from other domains.
One can read more about it on
Firebase Security rules
While the original question was answered (that the api key can be exposed - the protection of the data must be set from the DB rulles), I was also looking for a solution to restrict the access to specific parts of the DB.
So after reading this and some personal research about the possibilities, I came up with a slightly different approach to restrict data usage for unauthorised users:
I save my users in my DB too, under the same uid (and save the profile data in there). So i just set the db rules like this:
".read": "auth != null && root.child('/userdata/'+auth.uid+'/userRole').exists()",
".write": "auth != null && root.child('/userdata/'+auth.uid+'/userRole').exists()"
This way only a previous saved user can add new users in the DB so there is no way anyone without an account can do operations on DB.
Also adding new users is posible only if the user has a special role and edit only by admin or by that user itself (something like this):
"userdata": {
"$userId": {
".write": "$userId === auth.uid || root.child('/userdata/'+auth.uid+'/userRole').val() === 'superadmin'",
...
EXPOSURE OF API KEYS ISN'T A SECURITY RISK BUT ANYONE CAN PUT YOUR CREDENTIALS ON THEIR SITE.
Open api keys leads to attacks that can use a lot resources at firebase that will definitely cost your hard money.
You can always restrict you firebase project keys to domains / IP's.
https://console.cloud.google.com/apis/credentials/key
select your project Id and key and restrict it to Your Android/iOs/web App.
It is oky to include them, and special care is required only for Firebase ML or when using Firebase Authentication
API keys for Firebase are different from typical API keys:
Unlike how API keys are typically used, API keys for Firebase services are not used to control access to backend resources; that can only be done with Firebase Security Rules. Usually, you need to fastidiously guard API keys (for example, by using a vault service or setting the keys as environment variables); however, API keys for Firebase services are ok to include in code or checked-in config files.
Although API keys for Firebase services are safe to include in code, there are a few specific cases when you should enforce limits for your API key; for example, if you're using Firebase ML or using Firebase Authentication with the email/password sign-in method. Learn more about these cases later on this page.
For more informations, check the offical docs
I am making a blog website on github pages. I got an idea to embbed comments in the end of every blog page. I understand how firebase get and gives you data.
I have tested many times with project and even using console. I am totally disagree the saying vlit is vulnerable.
Believe me there is no issue of showing your api key publically if you have followed privacy steps recommend by firebase.
Go to https://console.developers.google.com/apis
and perfrom a security steup.
You should not expose this info. in public, specially api keys.
It may lead to a privacy leak.
Before making the website public you should hide it. You can do it in 2 or more ways
Complex coding/hiding
Simply put firebase SDK codes at bottom of your website or app thus firebase automatically does all works. you don't need to put API keys anywhere

How to pass for example firebase login data to vuejs [duplicate]

The Firebase Web-App guide states I should put the given apiKey in my Html to initialize Firebase:
// TODO: Replace with your project's customized code snippet
<script src="https://www.gstatic.com/firebasejs/3.0.2/firebase.js"></script>
<script>
// Initialize Firebase
var config = {
apiKey: '<your-api-key>',
authDomain: '<your-auth-domain>',
databaseURL: '<your-database-url>',
storageBucket: '<your-storage-bucket>'
};
firebase.initializeApp(config);
</script>
By doing so, the apiKey is exposed to every visitor.
What is the purpose of that key and is it really meant to be public?
The apiKey in this configuration snippet just identifies your Firebase project on the Google servers. It is not a security risk for someone to know it. In fact, it is necessary for them to know it, in order for them to interact with your Firebase project. This same configuration data is also included in every iOS and Android app that uses Firebase as its backend.
In that sense it is very similar to the database URL that identifies the back-end database associated with your project in the same snippet: https://<app-id>.firebaseio.com. See this question on why this is not a security risk: How to restrict Firebase data modification?, including the use of Firebase's server side security rules to ensure only authorized users can access the backend services.
If you want to learn how to secure all data access to your Firebase backend services is authorized, read up on the documentation on Firebase security rules. These rules control access to file storage and database access, and are enforced on the Firebase servers. So no matter if it's your code, or somebody else's code that uses you configuration data, it can only do what the security rules allow it to do.
For another explanation of what Firebase uses these values for, and for which of them you can set quotas, see the Firebase documentation on using and managing API keys.
If you'd like to reduce the risk of committing this configuration data to version control, consider using the SDK auto-configuration of Firebase Hosting. While the keys will still end up in the browser in the same format, they won't be hard-coded into your code anymore with that.
Update (May 2021): Thanks to the new feature called Firebase App Check, it is now actually possible to limit access to the backend services in your Firebase project to only those coming from iOS, Android and Web apps that are registered in that specific project.
You'll typically want to combine this with the user authentication based security described above, so that you have another shield against abusive users that do use your app.
By combining App Check with security rules you have both broad protection against abuse, and fine gained control over what data each user can access, while still allowing direct access to the database from your client-side application code.
Building on the answers of prufrofro and Frank van Puffelen here, I put together this setup that doesn't prevent scraping, but can make it slightly harder to use your API key.
Warning: To get your data, even with this method, one can for example simply open the JS console in Chrome and type:
firebase.database().ref("/get/all/the/data").once("value", function (data) {
console.log(data.val());
});
Only the database security rules can protect your data.
Nevertheless, I restricted my production API key use to my domain name like this:
https://console.developers.google.com/apis
Select your Firebase project
Credentials
Under API keys, pick your Browser key. It should look like this: "Browser key (auto created by Google Service)"
In "Accept requests from these
HTTP referrers (web sites)", add the URL of your app (exemple: projectname.firebaseapp.com/* )
Now the app will only work on this specific domain name. So I created another API Key that will be private for localhost developement.
Click Create credentials > API Key
By default, as mentioned by Emmanuel Campos, Firebase only whitelists localhost and your Firebase hosting domain.
In order to make sure I don't publish the wrong API key by mistake, I use one of the following methods to automatically use the more restricted one in production.
Setup for Create-React-App
In /env.development:
REACT_APP_API_KEY=###dev-key###
In /env.production:
REACT_APP_API_KEY=###public-key###
In /src/index.js
const firebaseConfig = {
apiKey: process.env.REACT_APP_API_KEY,
// ...
};
I am not convinced to expose security/config keys to client. I would not call it secure, not because some one can steal all private information from first day, because someone can make excessive request, and drain your quota and make you owe to Google a lot of money.
You need to think about many concepts from restricting people not to access where they are not supposed to be, DOS attacks etc.
I would more prefer the client first will hit to your web server, there you put what ever first hand firewall, captcha , cloudflare, custom security in between the client and server, or between server and firebase and you are good to go. At least you can first stop suspect activity before it reaches to firebase. You will have much more flexibility.
I only see one good usage scenario for using client based config for internal usages. For example, you have internal domain, and you are pretty sure outsiders cannot access there, so you can setup environment like browser -> firebase type.
The API key exposure creates a vulnerability when user/password sign up is enabled. There is an open API endpoint that takes the API key and allows anyone to create a new user account. They then can use this new account to log in to your Firebase Auth protected app or use the SDK to auth with user/pass and run queries.
I've reported this to Google but they say it's working as intended.
If you can't disable user/password accounts you should do the following:
Create a cloud function to auto disable new users onCreate and create a new DB entry to manage their access.
Ex: MyUsers/{userId}/Access: 0
exports.addUser = functions.auth.user().onCreate(onAddUser);
exports.deleteUser = functions.auth.user().onDelete(onDeleteUser);
Update your rules to only allow reads for users with access > 1.
On the off chance the listener function doesn't disable the account fast enough then the read rules will prevent them from reading any data.
I believe once database rules are written accurately, it will be enough to protect your data. Moreover, there are guidelines that one can follow to structure your database accordingly. For example, making a UID node under users, and putting all under information under it. After that, you will need to implement a simple database rule as below
"rules": {
"users": {
"$uid": {
".read": "auth != null && auth.uid == $uid",
".write": "auth != null && auth.uid == $uid"
}
}
}
}
No other user will be able to read other users' data, moreover, domain policy will restrict requests coming from other domains.
One can read more about it on
Firebase Security rules
While the original question was answered (that the api key can be exposed - the protection of the data must be set from the DB rulles), I was also looking for a solution to restrict the access to specific parts of the DB.
So after reading this and some personal research about the possibilities, I came up with a slightly different approach to restrict data usage for unauthorised users:
I save my users in my DB too, under the same uid (and save the profile data in there). So i just set the db rules like this:
".read": "auth != null && root.child('/userdata/'+auth.uid+'/userRole').exists()",
".write": "auth != null && root.child('/userdata/'+auth.uid+'/userRole').exists()"
This way only a previous saved user can add new users in the DB so there is no way anyone without an account can do operations on DB.
Also adding new users is posible only if the user has a special role and edit only by admin or by that user itself (something like this):
"userdata": {
"$userId": {
".write": "$userId === auth.uid || root.child('/userdata/'+auth.uid+'/userRole').val() === 'superadmin'",
...
EXPOSURE OF API KEYS ISN'T A SECURITY RISK BUT ANYONE CAN PUT YOUR CREDENTIALS ON THEIR SITE.
Open api keys leads to attacks that can use a lot resources at firebase that will definitely cost your hard money.
You can always restrict you firebase project keys to domains / IP's.
https://console.cloud.google.com/apis/credentials/key
select your project Id and key and restrict it to Your Android/iOs/web App.
It is oky to include them, and special care is required only for Firebase ML or when using Firebase Authentication
API keys for Firebase are different from typical API keys:
Unlike how API keys are typically used, API keys for Firebase services are not used to control access to backend resources; that can only be done with Firebase Security Rules. Usually, you need to fastidiously guard API keys (for example, by using a vault service or setting the keys as environment variables); however, API keys for Firebase services are ok to include in code or checked-in config files.
Although API keys for Firebase services are safe to include in code, there are a few specific cases when you should enforce limits for your API key; for example, if you're using Firebase ML or using Firebase Authentication with the email/password sign-in method. Learn more about these cases later on this page.
For more informations, check the offical docs
I am making a blog website on github pages. I got an idea to embbed comments in the end of every blog page. I understand how firebase get and gives you data.
I have tested many times with project and even using console. I am totally disagree the saying vlit is vulnerable.
Believe me there is no issue of showing your api key publically if you have followed privacy steps recommend by firebase.
Go to https://console.developers.google.com/apis
and perfrom a security steup.
You should not expose this info. in public, specially api keys.
It may lead to a privacy leak.
Before making the website public you should hide it. You can do it in 2 or more ways
Complex coding/hiding
Simply put firebase SDK codes at bottom of your website or app thus firebase automatically does all works. you don't need to put API keys anywhere

Firebase Security Open Access

My android wallpaper app is connected to Firebase Cloud Firestore. It doesn't have any user authentication because I want the user to be able to use it without fuss. To do this, it must be in open access, meaning, the user is allowed to read and write. This is dangerous as he can also edit and modify the data if he knows the project id. The project id is visible in the url of the app so this is not really a good choice. Closed access is also not an option for obvious reasons.
Is there anything I can do to protect my data without need of a user authentication? I would love to see the code needed for the Cloud Firestore and Storage to protect the data. I want the user to read only and I, as the owner, should be the only one who could write. Please refer to the images attached. Thanks a lot for taking time to answer my questions.
My data structure in Firebase Cloud Firestore:
Securing your data with Security Rules
Firebase Cloud Firestore, Firebase Realtime Database and Firebase Cloud Storage are secured by their own Security Rules. They provide access control and data validation in a simple yet expressive format and allow you to control access to documents and collections in your database.
To build user-based and role-based access systems that keep your users' data safe, you need to use Firebase Authentication with Cloud Firestore Security Rules.
Your specific use case
I assume that you store your data in Firebase Cloud Firestore and the wallpapers in Firebase Cloud Storage. The user then gets a document with a link to download a wallpaper and maybe also can upload their own wallpapers to the database.
The dangers of an open database
As you mentioned allowing all reads and writes to your database in a production app is very dangerous. Obviously, anyone with your database reference will be able to read or write data to your database. Unauthorized users could destroy your backend and there are also possibilities that costs could increase exponentially. Therefore this is not recommended. There always should be some mechanisms preventing these scenarios.
Recommendation: Using anonymous authentication first and connect later with existing Identity Providers
I recommend that you use Firebase Authentication to create and use temporary anonymous accounts to authenticate with Firebase. These temporary anonymous accounts can be used to allow users who haven't yet signed up to your app to work with data protected by security rules while not being in the way of your user experience. If an anonymous user later decides to sign up to your app, you can link their sign-in credentials to the anonymous account so that they can continue to work with their protected data in future sessions.
You could also enable Google-Sign-In, Facebook Login, Twitter, GitHub, Microsoft, Yahoo, etc. to let users authenticate in a very fast and easy way without compromising on a security standpoint if using regular password authentication is not what you want (from a UX standpoint). FirebaseUI makes it really easy to add these to your existing app. Check out the official documentation on this topic.
Implementing Cloud Firestore Security Rules
The official documentation on this is really great on how to get started with Cloud Firestore Security Rules.
However these security rules could work for you:
Allow read access to all users to the root (Not recommended because this can create huge costs in production). Users don't have write (create, update, delete) access. In this case you can edit your data via the Firebase Console. Choose either option 1 or option 2 for your project.
rules_version = '2';
service cloud.firestore {
match /databases/{database}/documents {
// Option 1: Matches any document in the 'root' collection.
match /root/{rumiXYZ} {
allow read: if true;
allow write: if false;
}
// Option 2: Matches any document in the 'root' collection or subcollections.
match /root/{document=**} {
allow read: if true;
allow write: if false;
}
}
}
The {document=**} path in the rules above can be used to match any document in the collection/subcollections or in the entire database. This should however not be necessary for your use case. Continue on to the guide for structuring security rules to learn how to match specific data paths and work with hierarchical data.
Don't forget to secure your Firebase Cloud Storage too!

Issuing API access to a registered third-party frontend app [duplicate]

The Firebase Web-App guide states I should put the given apiKey in my Html to initialize Firebase:
// TODO: Replace with your project's customized code snippet
<script src="https://www.gstatic.com/firebasejs/3.0.2/firebase.js"></script>
<script>
// Initialize Firebase
var config = {
apiKey: '<your-api-key>',
authDomain: '<your-auth-domain>',
databaseURL: '<your-database-url>',
storageBucket: '<your-storage-bucket>'
};
firebase.initializeApp(config);
</script>
By doing so, the apiKey is exposed to every visitor.
What is the purpose of that key and is it really meant to be public?
The apiKey in this configuration snippet just identifies your Firebase project on the Google servers. It is not a security risk for someone to know it. In fact, it is necessary for them to know it, in order for them to interact with your Firebase project. This same configuration data is also included in every iOS and Android app that uses Firebase as its backend.
In that sense it is very similar to the database URL that identifies the back-end database associated with your project in the same snippet: https://<app-id>.firebaseio.com. See this question on why this is not a security risk: How to restrict Firebase data modification?, including the use of Firebase's server side security rules to ensure only authorized users can access the backend services.
If you want to learn how to secure all data access to your Firebase backend services is authorized, read up on the documentation on Firebase security rules. These rules control access to file storage and database access, and are enforced on the Firebase servers. So no matter if it's your code, or somebody else's code that uses you configuration data, it can only do what the security rules allow it to do.
For another explanation of what Firebase uses these values for, and for which of them you can set quotas, see the Firebase documentation on using and managing API keys.
If you'd like to reduce the risk of committing this configuration data to version control, consider using the SDK auto-configuration of Firebase Hosting. While the keys will still end up in the browser in the same format, they won't be hard-coded into your code anymore with that.
Update (May 2021): Thanks to the new feature called Firebase App Check, it is now actually possible to limit access to the backend services in your Firebase project to only those coming from iOS, Android and Web apps that are registered in that specific project.
You'll typically want to combine this with the user authentication based security described above, so that you have another shield against abusive users that do use your app.
By combining App Check with security rules you have both broad protection against abuse, and fine gained control over what data each user can access, while still allowing direct access to the database from your client-side application code.
Building on the answers of prufrofro and Frank van Puffelen here, I put together this setup that doesn't prevent scraping, but can make it slightly harder to use your API key.
Warning: To get your data, even with this method, one can for example simply open the JS console in Chrome and type:
firebase.database().ref("/get/all/the/data").once("value", function (data) {
console.log(data.val());
});
Only the database security rules can protect your data.
Nevertheless, I restricted my production API key use to my domain name like this:
https://console.developers.google.com/apis
Select your Firebase project
Credentials
Under API keys, pick your Browser key. It should look like this: "Browser key (auto created by Google Service)"
In "Accept requests from these
HTTP referrers (web sites)", add the URL of your app (exemple: projectname.firebaseapp.com/* )
Now the app will only work on this specific domain name. So I created another API Key that will be private for localhost developement.
Click Create credentials > API Key
By default, as mentioned by Emmanuel Campos, Firebase only whitelists localhost and your Firebase hosting domain.
In order to make sure I don't publish the wrong API key by mistake, I use one of the following methods to automatically use the more restricted one in production.
Setup for Create-React-App
In /env.development:
REACT_APP_API_KEY=###dev-key###
In /env.production:
REACT_APP_API_KEY=###public-key###
In /src/index.js
const firebaseConfig = {
apiKey: process.env.REACT_APP_API_KEY,
// ...
};
I am not convinced to expose security/config keys to client. I would not call it secure, not because some one can steal all private information from first day, because someone can make excessive request, and drain your quota and make you owe to Google a lot of money.
You need to think about many concepts from restricting people not to access where they are not supposed to be, DOS attacks etc.
I would more prefer the client first will hit to your web server, there you put what ever first hand firewall, captcha , cloudflare, custom security in between the client and server, or between server and firebase and you are good to go. At least you can first stop suspect activity before it reaches to firebase. You will have much more flexibility.
I only see one good usage scenario for using client based config for internal usages. For example, you have internal domain, and you are pretty sure outsiders cannot access there, so you can setup environment like browser -> firebase type.
The API key exposure creates a vulnerability when user/password sign up is enabled. There is an open API endpoint that takes the API key and allows anyone to create a new user account. They then can use this new account to log in to your Firebase Auth protected app or use the SDK to auth with user/pass and run queries.
I've reported this to Google but they say it's working as intended.
If you can't disable user/password accounts you should do the following:
Create a cloud function to auto disable new users onCreate and create a new DB entry to manage their access.
Ex: MyUsers/{userId}/Access: 0
exports.addUser = functions.auth.user().onCreate(onAddUser);
exports.deleteUser = functions.auth.user().onDelete(onDeleteUser);
Update your rules to only allow reads for users with access > 1.
On the off chance the listener function doesn't disable the account fast enough then the read rules will prevent them from reading any data.
I believe once database rules are written accurately, it will be enough to protect your data. Moreover, there are guidelines that one can follow to structure your database accordingly. For example, making a UID node under users, and putting all under information under it. After that, you will need to implement a simple database rule as below
"rules": {
"users": {
"$uid": {
".read": "auth != null && auth.uid == $uid",
".write": "auth != null && auth.uid == $uid"
}
}
}
}
No other user will be able to read other users' data, moreover, domain policy will restrict requests coming from other domains.
One can read more about it on
Firebase Security rules
While the original question was answered (that the api key can be exposed - the protection of the data must be set from the DB rulles), I was also looking for a solution to restrict the access to specific parts of the DB.
So after reading this and some personal research about the possibilities, I came up with a slightly different approach to restrict data usage for unauthorised users:
I save my users in my DB too, under the same uid (and save the profile data in there). So i just set the db rules like this:
".read": "auth != null && root.child('/userdata/'+auth.uid+'/userRole').exists()",
".write": "auth != null && root.child('/userdata/'+auth.uid+'/userRole').exists()"
This way only a previous saved user can add new users in the DB so there is no way anyone without an account can do operations on DB.
Also adding new users is posible only if the user has a special role and edit only by admin or by that user itself (something like this):
"userdata": {
"$userId": {
".write": "$userId === auth.uid || root.child('/userdata/'+auth.uid+'/userRole').val() === 'superadmin'",
...
EXPOSURE OF API KEYS ISN'T A SECURITY RISK BUT ANYONE CAN PUT YOUR CREDENTIALS ON THEIR SITE.
Open api keys leads to attacks that can use a lot resources at firebase that will definitely cost your hard money.
You can always restrict you firebase project keys to domains / IP's.
https://console.cloud.google.com/apis/credentials/key
select your project Id and key and restrict it to Your Android/iOs/web App.
It is oky to include them, and special care is required only for Firebase ML or when using Firebase Authentication
API keys for Firebase are different from typical API keys:
Unlike how API keys are typically used, API keys for Firebase services are not used to control access to backend resources; that can only be done with Firebase Security Rules. Usually, you need to fastidiously guard API keys (for example, by using a vault service or setting the keys as environment variables); however, API keys for Firebase services are ok to include in code or checked-in config files.
Although API keys for Firebase services are safe to include in code, there are a few specific cases when you should enforce limits for your API key; for example, if you're using Firebase ML or using Firebase Authentication with the email/password sign-in method. Learn more about these cases later on this page.
For more informations, check the offical docs
I am making a blog website on github pages. I got an idea to embbed comments in the end of every blog page. I understand how firebase get and gives you data.
I have tested many times with project and even using console. I am totally disagree the saying vlit is vulnerable.
Believe me there is no issue of showing your api key publically if you have followed privacy steps recommend by firebase.
Go to https://console.developers.google.com/apis
and perfrom a security steup.
You should not expose this info. in public, specially api keys.
It may lead to a privacy leak.
Before making the website public you should hide it. You can do it in 2 or more ways
Complex coding/hiding
Simply put firebase SDK codes at bottom of your website or app thus firebase automatically does all works. you don't need to put API keys anywhere

Securely use other Firebase services in a Firebase Hosting app [duplicate]

The Firebase Web-App guide states I should put the given apiKey in my Html to initialize Firebase:
// TODO: Replace with your project's customized code snippet
<script src="https://www.gstatic.com/firebasejs/3.0.2/firebase.js"></script>
<script>
// Initialize Firebase
var config = {
apiKey: '<your-api-key>',
authDomain: '<your-auth-domain>',
databaseURL: '<your-database-url>',
storageBucket: '<your-storage-bucket>'
};
firebase.initializeApp(config);
</script>
By doing so, the apiKey is exposed to every visitor.
What is the purpose of that key and is it really meant to be public?
The apiKey in this configuration snippet just identifies your Firebase project on the Google servers. It is not a security risk for someone to know it. In fact, it is necessary for them to know it, in order for them to interact with your Firebase project. This same configuration data is also included in every iOS and Android app that uses Firebase as its backend.
In that sense it is very similar to the database URL that identifies the back-end database associated with your project in the same snippet: https://<app-id>.firebaseio.com. See this question on why this is not a security risk: How to restrict Firebase data modification?, including the use of Firebase's server side security rules to ensure only authorized users can access the backend services.
If you want to learn how to secure all data access to your Firebase backend services is authorized, read up on the documentation on Firebase security rules. These rules control access to file storage and database access, and are enforced on the Firebase servers. So no matter if it's your code, or somebody else's code that uses you configuration data, it can only do what the security rules allow it to do.
For another explanation of what Firebase uses these values for, and for which of them you can set quotas, see the Firebase documentation on using and managing API keys.
If you'd like to reduce the risk of committing this configuration data to version control, consider using the SDK auto-configuration of Firebase Hosting. While the keys will still end up in the browser in the same format, they won't be hard-coded into your code anymore with that.
Update (May 2021): Thanks to the new feature called Firebase App Check, it is now actually possible to limit access to the backend services in your Firebase project to only those coming from iOS, Android and Web apps that are registered in that specific project.
You'll typically want to combine this with the user authentication based security described above, so that you have another shield against abusive users that do use your app.
By combining App Check with security rules you have both broad protection against abuse, and fine gained control over what data each user can access, while still allowing direct access to the database from your client-side application code.
Building on the answers of prufrofro and Frank van Puffelen here, I put together this setup that doesn't prevent scraping, but can make it slightly harder to use your API key.
Warning: To get your data, even with this method, one can for example simply open the JS console in Chrome and type:
firebase.database().ref("/get/all/the/data").once("value", function (data) {
console.log(data.val());
});
Only the database security rules can protect your data.
Nevertheless, I restricted my production API key use to my domain name like this:
https://console.developers.google.com/apis
Select your Firebase project
Credentials
Under API keys, pick your Browser key. It should look like this: "Browser key (auto created by Google Service)"
In "Accept requests from these
HTTP referrers (web sites)", add the URL of your app (exemple: projectname.firebaseapp.com/* )
Now the app will only work on this specific domain name. So I created another API Key that will be private for localhost developement.
Click Create credentials > API Key
By default, as mentioned by Emmanuel Campos, Firebase only whitelists localhost and your Firebase hosting domain.
In order to make sure I don't publish the wrong API key by mistake, I use one of the following methods to automatically use the more restricted one in production.
Setup for Create-React-App
In /env.development:
REACT_APP_API_KEY=###dev-key###
In /env.production:
REACT_APP_API_KEY=###public-key###
In /src/index.js
const firebaseConfig = {
apiKey: process.env.REACT_APP_API_KEY,
// ...
};
I am not convinced to expose security/config keys to client. I would not call it secure, not because some one can steal all private information from first day, because someone can make excessive request, and drain your quota and make you owe to Google a lot of money.
You need to think about many concepts from restricting people not to access where they are not supposed to be, DOS attacks etc.
I would more prefer the client first will hit to your web server, there you put what ever first hand firewall, captcha , cloudflare, custom security in between the client and server, or between server and firebase and you are good to go. At least you can first stop suspect activity before it reaches to firebase. You will have much more flexibility.
I only see one good usage scenario for using client based config for internal usages. For example, you have internal domain, and you are pretty sure outsiders cannot access there, so you can setup environment like browser -> firebase type.
The API key exposure creates a vulnerability when user/password sign up is enabled. There is an open API endpoint that takes the API key and allows anyone to create a new user account. They then can use this new account to log in to your Firebase Auth protected app or use the SDK to auth with user/pass and run queries.
I've reported this to Google but they say it's working as intended.
If you can't disable user/password accounts you should do the following:
Create a cloud function to auto disable new users onCreate and create a new DB entry to manage their access.
Ex: MyUsers/{userId}/Access: 0
exports.addUser = functions.auth.user().onCreate(onAddUser);
exports.deleteUser = functions.auth.user().onDelete(onDeleteUser);
Update your rules to only allow reads for users with access > 1.
On the off chance the listener function doesn't disable the account fast enough then the read rules will prevent them from reading any data.
I believe once database rules are written accurately, it will be enough to protect your data. Moreover, there are guidelines that one can follow to structure your database accordingly. For example, making a UID node under users, and putting all under information under it. After that, you will need to implement a simple database rule as below
"rules": {
"users": {
"$uid": {
".read": "auth != null && auth.uid == $uid",
".write": "auth != null && auth.uid == $uid"
}
}
}
}
No other user will be able to read other users' data, moreover, domain policy will restrict requests coming from other domains.
One can read more about it on
Firebase Security rules
While the original question was answered (that the api key can be exposed - the protection of the data must be set from the DB rulles), I was also looking for a solution to restrict the access to specific parts of the DB.
So after reading this and some personal research about the possibilities, I came up with a slightly different approach to restrict data usage for unauthorised users:
I save my users in my DB too, under the same uid (and save the profile data in there). So i just set the db rules like this:
".read": "auth != null && root.child('/userdata/'+auth.uid+'/userRole').exists()",
".write": "auth != null && root.child('/userdata/'+auth.uid+'/userRole').exists()"
This way only a previous saved user can add new users in the DB so there is no way anyone without an account can do operations on DB.
Also adding new users is posible only if the user has a special role and edit only by admin or by that user itself (something like this):
"userdata": {
"$userId": {
".write": "$userId === auth.uid || root.child('/userdata/'+auth.uid+'/userRole').val() === 'superadmin'",
...
EXPOSURE OF API KEYS ISN'T A SECURITY RISK BUT ANYONE CAN PUT YOUR CREDENTIALS ON THEIR SITE.
Open api keys leads to attacks that can use a lot resources at firebase that will definitely cost your hard money.
You can always restrict you firebase project keys to domains / IP's.
https://console.cloud.google.com/apis/credentials/key
select your project Id and key and restrict it to Your Android/iOs/web App.
It is oky to include them, and special care is required only for Firebase ML or when using Firebase Authentication
API keys for Firebase are different from typical API keys:
Unlike how API keys are typically used, API keys for Firebase services are not used to control access to backend resources; that can only be done with Firebase Security Rules. Usually, you need to fastidiously guard API keys (for example, by using a vault service or setting the keys as environment variables); however, API keys for Firebase services are ok to include in code or checked-in config files.
Although API keys for Firebase services are safe to include in code, there are a few specific cases when you should enforce limits for your API key; for example, if you're using Firebase ML or using Firebase Authentication with the email/password sign-in method. Learn more about these cases later on this page.
For more informations, check the offical docs
I am making a blog website on github pages. I got an idea to embbed comments in the end of every blog page. I understand how firebase get and gives you data.
I have tested many times with project and even using console. I am totally disagree the saying vlit is vulnerable.
Believe me there is no issue of showing your api key publically if you have followed privacy steps recommend by firebase.
Go to https://console.developers.google.com/apis
and perfrom a security steup.
You should not expose this info. in public, specially api keys.
It may lead to a privacy leak.
Before making the website public you should hide it. You can do it in 2 or more ways
Complex coding/hiding
Simply put firebase SDK codes at bottom of your website or app thus firebase automatically does all works. you don't need to put API keys anywhere

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