问题
So if I have an E-commerce App that doesn't require Login/Auth, and my users buy in the store, then after verifying the transaction the backend writes the order in the database.
The thing is that my Realtime Database just relies on Stripe transaction key (i.e, someone has paid for an item) to be able to write on the DB, because my rules are set so anyone can write, otherwise I would need every user to log in, but that's not what I want.
Firebase recently notified me that my rules are weak.
How can a make sure my users are able to write to my database in a secure way for my app, without log in/Auth?
回答1:
There are many different security models you can use with Firebase, and it's important to understand the level of security each provides.
One thing to look into is anonymous auth which lets you "authenticate" a user without actually requiring them to provide any credentials. This provides a way to guarantee that the same device is being used between multiple reads/writes.
In your specific case, it sounds like you might be looking to rely on unguessable tokens. This can be a valid security model for some use cases so long as the key is sufficiently complex as to be unguessable.
At its most basic, the way you'd structure security rules for unguessable URLs is something like:
{
"rules": {
"transactions": {
"$key": {
".read": true,
".write": true
}
}
}
}
This allows users to read/write specific nodes at e.g. transactions/abc123xyzunguessable but importantly does not allow reading/writing to the parent transactions node. Security comes from the fact that only the person who originally got the unguessable token will be able to provide it again in the future.
A better implementation would gate writing on the $key matching the expected unguessable format, adding validation and other read/write rules to ensure that the data is formatted appropriately, and probably also prevent modification of key fields.
These are just some pointers but should help you on your way. The important thing is to make sure that you never leave important information in a place where it can be read through easily guessable URLs.
回答2:
There is no "secure" way to allow writes to Realtime Database without Firebase Authentication. Without Firebase Auth, either there is full public access, or there is no public access at all.
If you can't use Firebase Auth, what you will need to do instead is make your security rules disallow all direct access to the database from client applications, then create backend APIs to manage access to the database. Your backend APIs will need to somehow validate that the person making the request should have the ability to make the required changes. Then, it will have to use the Firebase Admin SDK to commit those changes to the database.
来源：https://stackoverflow.com/questions/61393400/how-can-any-user-write-to-my-database-securely-in-firebase-without-auth