Firebase basic rules issues - javascript

I have a firebase realtime database that stores users information. I am creating a dashboard where I can track all of this , but I am having trouble with creating secure rules. I want to be able to read and write on this dashboard but users cannot read the database. I will be the only person on the dashboard since its local. I was thinking of like checking for an api key that I can have in the dashboard but I cannot find any information online. If you have any suggestions please let me know. These are my current rules below. I have it to where nobody can read the database but they can write to it. I want to be able to read the database from the dashboard.
{
"rules": {
".read": "false",
".write": true,
"posts": {
"$uid": {
".write": "!data.exists()"
}
}
}
}

The security rules will depend on what exactly it is that the users can read/write but if you wanted to be the only person who can do either you could set the security rules to something like,
{
"rules": {
"users": {
"$node_with_data": {
".write": "auth.uid === 'enter_your_uid_here_123' ",
".read": "auth.uid === 'enter_your_uid_here_123' "
}
}
}
}
This means that the only person who can read/write to the node specified is the the user with the uid that matches the one you enter. Obviously this would mean the users couldn't write to this node so you'll need to think about what types of users you have and what they're allowed to access.
Here's a useful link Firebase Security Rules

What I did is use firebase Authentication and what I can do is allow only authenticated users through since I don't authenticate anyone or I can only let my Gmail through which works great! Mine looks like this
{
"rules": {
".read": "auth.token.email_verified == true && auth.token.email.matches(/YOUROWNEMAIL/)",
".write": true,
"posts": {
"$uid": {
".write": "!data.exists()" // This makes it so nobody can delete anything
}
}
}
}

Related

login with mails added to checklist -javascript

Have a realtime db login auth rules.
When I enter the mails manually, the mails I authorize gain access, there is no problem. Here is code:
{
"rules": {
".read": "
auth.token.email == \"xx#qq.co\"
|| auth.token.email == \"yy.yy#yy.co\"
|| auth.token.email == \"ss#ss.com\"
",
".write": true
}
}
But my idea:
{"emails":{"xx#hotmail.com", "qq#gmail.com"},
{
"rules": {
".read": "auth.token.email == emails",
".write": true
}
and realtime db code screenshot:
any idea this issue?
That second snippet looks like invalid syntax for Firebase security rules, and thus won't work (it actually shouldn't even save when you enter that in the Firebase console).
If you want a dynamic list of user to gain access, the idiomatic way is to store their UIDs in the database and then check against that in your security rules.
So for example, you could have this in the database:
"uidsThatAreAllowedToRead": {
"uid1": true,
"uid2": true,
"uid3": true
}
And then in your read rule check against that with:
".read": "root.child('uidsThatAreAllowedToRead').child(auth.uid).exists()"
You could do the same with email addresses, but you'd have to encode them as keys cannot contain . characters which are required in an email address. The common encoding method is to replace each . with a ,, which conveniently is allowed in the database keys but not in email addresses.

How do I create a record in firebase with a specific users credential?

I have a requirement of an app that has a contact form. I need to add records securely with the realtime database rules set to the uid of a specific user say my creds to prevent someone from adding records to the dB from anywhere but my form.
All the articles I looked talked about firebase in test mode with the rules set as read and write to true but doing so someone can have access to my dB and populate records from anywhere.
Have a look at the Firebase documentation on implementing content-owner only access, which contains these rules for the Realtime Database:
{
"rules": {
"some_path": {
"$uid": {
// Allow only authenticated content owners access to their data
".read": "auth != null && auth.uid == $uid"
".write": "auth != null && auth.uid == $uid"
}
}
}
}
To write to this database, the user would need to be signed in, and then:
firebase.database().ref('some_path').child(firebase.auth().currentUser.uid).set("hello world");

Firebase Database Rules for multi-update transactions

I’m trying to create security rules for the “Save data as transactions” blogging app example from the Firebase guide.
The user can increase or decrease the star count for a post, having his own UID being included or removed from the node at the same time.
I’ve written the following rules:
(I removed the rules for the counter increase/decrease since they are out of the scope of the question)
“stars”: {
".read": true,
"$postId”: {
".write": "auth != null && (newData.child('users').child(auth.uid).exists() || data.child('users').child(auth.uid).exists())",
"users": {
"$userId": {
".validate": "$userId === auth.uid"
}
}
}
}
And an exemple of a stars node:
“stars”: {
“postId1”: {
starCount: 2,
"users": {
“userId1”: true,
“userId2”: true
}
}
}
The rules work fine for adding an user to the “users” node, but a problem arises when removing.
It’s possible for a mean-spirited user to remove any other user from the “users” node, just update it with a empty node. Or a node with all the users from before, minus one he chose to remove.
The “.validate” rule ("$userId === auth.uid") does not work for a empty node being submited and I can't write a rule that checks if all the users that were in the database before the update are still there after.
The way I’d solve the problem if I wasn’t using transactions was to to move the “.write” rule to under “$userId”, limiting the uptate for only one user at a time and only with the same UID as the logged user.
Something like:
“stars”: {
".read": true,
"$postId”: {
"users": {
"$userId": {
".write": "auth != null && $userId === auth.uid"
}
}
}
"starCount": {
".write": true
}
But since I’m doing the database update using transactions I need the “.write” rule under the "$postId”, permitting the update of the “users” node and the “starCount” node at the same time. Something that would not be possible in my last exemple (no “.write” rule under "$postId”).
So it seem like a Catch-22. Or I use transactions but I’m not able to secure the starCount with rules, or I do it as a normal multi-update but loose the concurrency benefits for increasing the counter.
How can I correctly secure the “Save data as transactions” blogging app exemple?

Firebase Security Issues - How to Have One User Change Another's DB Object?

I'm building an HTML/JavaScript/CSS front-end application using only Firebase as my backend (and I'd like to keep it that way, but I'm not sure if what I want to do is possible without another server).
I'm trying to implement a following/followers functionality. I have a node in the Firebase database that is basically a list of users. The object key is the user's auth uid, and the value is an object describing properties of that user object.
I want to have a "follow" button in my app that, when clicked, adds an object with the uid of the user being followed to the "following" object of the current user. Also, I want to add an object with the current user's uid to the "followers" node of the user being followed.
followers node:
following node:
The trouble I'm having is that Firebase recommends to set up their security rules something like this:
{
"rules": {
"users": {
"$uid": {
".write": "$uid === auth.uid"
}
}
}
}
This way it's fine to expose your firebase key because any given authenticated user can only write to his own object in the database. So my question is: What's the best way for me to allow one user to modify another's database object (by writing to the other user's "followers" node) while still preventing anyone with my Firebase key from maliciously writing to any/every user's object?
Since firebase dataBase grantings overwrite higher level revocations, you can just leave the rule as it is and grant write permission to all users to the followers node of each user:
{
"rules": {
"users": {
"$uid": {
".write": "$uid === auth.uid"
"followers": {
".write": auth != null
}
}
}
}
You can also add a verification to the node written to followers such as !data.exists() && newData.child("uid").val() === auth.uidto prevent users from deleting/modifying other user's followers and prevent adding random uid's as followers
Edit:
Let's imagine your database structure is the folowing:
{
users: {
uid: {
(user data)
followers: {
uid : timestamp
}
}
}
}
Then the rules would be:
{
"rules": {
"users": {
"$uid": {
".write": "$uid === auth.uid",
"followers": {
"$follower": {
".write": "auth != null && !data.exists() && newData.key() === auth.uid"
}
}
That way, one user can only write new entries in the other users' followers node and that entry's key must be his uid.
}
}

Unique IP write permissions Firebase collection

Let's say I have a collection of articles:
https://example.firebaseio.com/articles/$key
And I want to add a viewCounter and currentUsersCounter children to articles.
https://example.firebaseio.com/articles/$key/viewCounter
https://example.firebaseio.com/articles/$key/currentUsersCounter
I execute a function anytime a user has scrolled into the next article:
var currentArticle = function(key){
//key == index of the article
//This is where I want to increment the `viewCounter` and `currentUsersCounter`
}
Obviously I don't want anyone writing to anything more then those two children.
How do I expand on my security rules which currently (black-lists all writes) to white-listing writes only for these specific collections?
How would I limit writes to unique IP addresses in my security rules for these white-listed collections? (if possible)
Currently black-listing all writes:
{
"rules": {
".read": true,
".write": "auth.email == 'example#gmail.com'"
}
}
You can't do this in a way that will protect the integrity of the data (i.e. ensuring that the counts are actually accurate), since if you grant write access to those fields a client can write whatever value it wants to it.
You can, however, provide granular read/write access for only those specific children by using variables in your security rules:
{
"articles": {
"$key": {
"viewCounter": {
".write": true,
".validate": "newData.isNumber() && newData.val() == data.val() + 1"
},
"$other": {
".write": "auth.email == 'example#gmail.com'"
}
}
}
}
It is not possible to do any filtering based on IP addresses. You'll want to use a secret from trusted server code to do that as suggested in the comment.

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