How do you use Firebase Auth without a Web Token

Question

I am using a third party sdk to sign in users. However that sdk does not generate any token as such. It returns the mobile and user Name.

But I use Firebase for all my other requirements. Thus i need to add the users in the Auth system so i can securely use my realtime database and storage.

• https://firebase.google.com/docs/auth/admin/create-custom-tokens

I did go through this but this suggests adding logic to the authentication server, which I dont have access to so i cant make changes to incorporate a JWT.

Can someone please suggest a way to do so?

Answer 1

Generating custom tokens requires a server environment as sensitive private keys are involved in that process. Consider using an HTTP endpoint with Cloud Functions to do so.

Note the 3rd party SDK you are using must be able to produce the authentication assertion server side too, as you can't just send a username to that endpoint and mint a custom token from that. That can easily be abused.