How can I create a new Firebase Admin SDK server in NodeJS to authenticate with LinkedIn?

Question

I've never worked with NodeJS, and I need to create a Firebase custom token so I can authenticate to my iOS app via LinkedIn.

According to the Firebase documentation, I have to create a new Firebase Admin SDK server. I'm following the NodeJS instructions, but they're not well explained. I don't understand how to communicate to the server with my app, and I can't find much documentation about it.

Has someone done this before? If so, I will appreciate your help.

Thanks.

Answer 1

you can do the following simplified flow(other ways to do it too):

• (assuming you have the infrastructure to do that) Sign in with linkedIn in your iOS app. Once that's done, send the linkedIn OAuth access token to your backend running node.js.
• On your backend, query the linkedIn userinfo endpoint with that access token. Get the linkedIn userId, displayName, photoUrl.
• Using the linkedIn userID, mint a customToken using the node.js admin SDK and set the uid to the linkedIn userID. You can prefix it with something to prevent collision.
• Return the custom token, displayName and photoUrl to your iOS app.
• Call signInWithCustom using that custom token returned to sign in that user.
• Set the displayName and photoURL on that logged in user.

You now have a linkedIn user with their linkedIn display name and photoURL logged in to firebase.