I'm new to Firebase, and I'm not sure I'm going about what I'm trying to do the right way, but my question is essentially the title. For an app, I'd like to restrict my functions in Firebase to only be available on a custom hostname I've configured. I'm not sure if there is an easy enough way to do this without creating separate Firebase projects?
My main goal is to setup the functions to respond on a url like api.myapp.com while hooking into authentication that can have callback emails that are sent from myapp.com. I've done some digging and can't seem to find much on how to go about this. Thanks in advance!
The documentation says
The steps required to set up API Gateway to manage and secure a Cloud
Functions backend service are outlined in the API Gateway Quickstarts.
Documentation also says
API Gateway uses Identity and Access Management (IAM) to control
access to your API.
IAM is very granular and would allow you to specify domain names for allow action.
Related
I have a desktop app that will be distributed to users, and part of its code (which the user might be able to access) has to perform an API call to a third-party web service. However, this requires the API keys to be embedded into the source code, which causes some obvious security issues.
The main solution I've found while researching on the subject is to have a backend server between the user and the third-party API endpoint. So, I've been looking into Firebase for a while and it seems that this solution can be implemented using Firestore and Cloud Functions.
But, I wasn't able to find any clear examples that achieve something like this, and since I have no previous experience with Firebase or just backend programming in general, I would like to know if I'm on the right track and get more details about how to get it done, or if there are better alternatives for solving this issue. Any input is appreciated, thx.
You can use the firebase cloud functions as you mentioned. Your desktop application will be communicating with the cloud function - simple API call. Here you can find examples how to implement and deploy functions and test it locally https://firebase.google.com/docs/functions/get-started. Your cloud function will hold the API keys (it is backend so it will be secure if you dont expose it explicitly. Also the backend to backend communication is considered as secure). Finally, this cloud function will call the third party service and return some data back to the desktop app if needed. So you are on the right track, that is how the design should look like. If you need some help with cloud functions, you can also contact me directly.
I have a Node.js API (built with Express.js) hosted on Firebase Cloud Functions and an accompanying web application hosted on Firebase Hosting which is supposed to interact with the aforementioned API.
I would like to restrict calls to the API so that only the web application would be able to call the cloud functions. How can I achieve that?
What I have tried:
using the App Check or more precisely Google's reCAPTCHA v3 for web apps. I have whitelisted the domain of the web application and have activated App Check token validation server side as well. The problem with App Check, however, is that I am able to obtain the reCAPTCHA attestation token from the browser (after authenticating through the web app) and use that with requests made from anywhere. This enables bombarding the API from outside the web application and defeats the purpose of using App Check in the first place.
Something to note here, the documentation for activating App Check in Cloud Functions instructs the usage of functions.https.onCall(). However, since my API is built using Express.js, I had to use a workaround to be able to use functions.https.onRequest() as instructed here.
restricting the Cloud Function from Google Cloud console to allow only clients of the same project to call the function as instructed here. Unfortunately, my web application hosted on Firebase Hosting does not seem to belong under the same Google Cloud project. Apps hosted on Firebase Hosting do not appear in Google Cloud console. Furthermore, after adjusting the Ingress settings of the functions to "allow internal traffic only", I am receiving CORS errors when attempting to access the API through the web application. I am unable to access the API from anywhere else though, which is partly the desired outcome.
Before anyone proposes limiting the domains in CORS options from within the API, while this might serve the purpose of restricting access to the API endpoints, it still would allow calling the function rapidly and thus, potentially, racking up the bill.
I am grateful for any suggestions!
Firebaser here.
This is a great question! Doug has already made some great points above, and I'll just add to that by saying that the TTL on App Check tokens reduce the replay window that you observed in your first bullet point, and this TTL is configurable.
The default TTL for reCAPTCHA v3 is 1 day to protect against running out of quota, but you can set a shorter TTL to increase the cost for an attacker trying to set up a replay attack. But please do be mindful of the associated trade-offs as described in the documentation. You can read about the associated quotas and limits here.
Unfortunately, web applications redirected from Firebase Hosting can't hook up to the GCP internal network. App Check is actually exactly what you are looking for in this situation.
Finally, because we are continuously working on improving the App Check platform, the comments you leave here are valuable for us as we decide on what anti-abuse features we want to work on next.
I have to build an API using Firebase, and need some help with design choices. I want to be able to sell the API to users, who can then use it to build/integrate their own applications. Users will have both read and write privileges.
General information:
I'm using Firestore db with email & password authentication.
Only specifically assigned users may use the API
Each user may only access specific documents concerning them.
I've noticed 3 different ways in which an API can be provided to a user of my Firestore db:
https triggered cloud functions (https://firebase.google.com/docs/functions/http-events)
Using the SDK (https://firebase.google.com/docs/firestore/client/libraries)
Using the REST API provided by Firbase (https://firebase.google.com/docs/firestore/use-rest-api)
API requirements:
Used only by users that I specifically grant access to (email & password login)
I want to limit these users to only a couple of read/write tasks that they're able to perform.
It needs to be safe.
My current approach is:
Use the 3rd option - the REST API provided by Firebase (thereby giving users the projectId and API key)
Add authorised users to the list of authorised accounts on Firbase, and limit access using custom claims and database rules.
My questions:
It seems that https functions (option 1) are normally used in API building. Are options 2 and 3 unsafe?
What are the normal use cases of the 3 options? When should each be used and when should each be avoided?
Are there any obvious flaws in my choice of option 3?
Any other useful information about making these design decisions will be much appreciated.
Thank you in advance
TL;DL: It depends on what you want to do with this API and how many and what type of devices/users will be calling it.
Before answering your questions I will list below the advantages of each approach:
Cloud Functions:
Cloud Function is a Functions as a Service Solution, so it's also a hosting service for your API, therefore you won't have to provision, manage, or upgrade servers and the API will automatically scale based on the load. Also this option takes into account the pros of SDKs and client libraries, since your code will have to use it to connect to Firestore anyway.
SDKs and client libraries:
This is the easiest and more optimized way to reach Firestore, however, environments where running a native library is not possible such as IOT devices will be left out of your solution, so consider this while implementing this option.
Cloud Firestore REST API:
Every device properly authorized to access Firestore will be able to do so.
NOTE: For both SDK and REST API you will need to consider hosting of your API, either on Cloud Functions, as mentioned, App Engine Standard, App Engine Flex or a Compute Engine Server Instance.
All that being said, it's up to you and your API's usage and requirements to say which option is best considering the points above.
As per security, I'd say that all option can be secure if firebase rules and firebase auth are set correctly.
I want to call my firebase function HTTP API from another server -- which does not have an email and password (or any other firebase authentication method).
I want to be able to run a task like read/write in Firestore, however still protect the API. I would like to create some sort of programmatic keys like AWS does for calling their APIs. But, how to do this in firebase ? How can we generate such programmatic keys to communicate between one server to another?
It seems that the best available option that you might try - because it doesn't seem to have an official way to do it - it's by using API keys to perform the verification and security of your calls. As clarified in the official documentation Using API Keys, this is not supported by all Google applications, but Cloud Endpoints should work.
Considering that, you can use Cloud Endpoints in integration with your Cloud Functions, to provide security via API keys. You can find more information on how to achieve that in this article here.
Another alternative you may want to try, it's using a JWT token - as clarified here - as a header in your API calls. This way, you will be working with authetnication via keys - not exactly as in AWS, but it's a start - so you can secure your calls. :)
Anyway, if you don't find this useful, I would recommend you to raise a Feature Request in Google's Feature Tracker, so they can check about the possibility of further implementation in such functionality.
Let me know if the information helped you!
Using Firebase stack for chrome extensions :) However, have one BIG problem.
Users located in China cant use the app since Google is blocked there thus Firebase authentication fails ... well, one option is to use VPN but in terms of user experience, it's a big No No ... is there any better way to resolve/workaround this issue
Using mainly firebase auth (Google provider) and Firestore
Can use somehow custom tokens to resolve this?
https://firebase.google.com/docs/auth/admin/create-custom-tokens
Or external authentication service combined with firebase, in this case, need to have authenticated access to firestore as well
Create an API on HEROKU. Make all your Oauth and every call made for firebase go through the API. This API will only bridge all information between CHINA and GoogleServices (Firebase) since the great firewall blocks them.
The simplest solution may be to set up a proxy server to forward your apps requests to Firebase.