Steam -> Firebase token generator

1. Enables users to log in via steam, then redirects passing a firebase auth token as query (via ?token=blabla).
2. Users can link their Discord app to their steam account.

Questions? Suggestions?: Open an issue here or join Discord: https://discord.gg/3hVMYH3

Running

Dev: yarn dev Prod: yarn start

In your consuming app redirect the user to to /auth/steam?client_id=<clientId>. clientId needs to be configured in the CLIENTS environment variable (see below).

Configuration

Copy .env.example to .env and fill in custom values. FIREBASE_SERVICE_ACC is a firebase service account as json. CLIENTS is json in the format { clientId: redirectUrl }

Example:

You have configured CLIENTS['my-app'] = 'https://yourdomain.com/login_return'. You redirect the user to https://firebase-steam-login/auth/steam?client_id=my-app. After the login is finished the user will be redirected to https://yourdomain.com/login_return?token=aehcndb3u584.... If the login fails they are redirected to https://yourdomain.com/login_return?code=error/code.

Deploying to Firebase Functions

Make sure the project is set up as firebase project by running firebase init

Next fill all configuration variables. Firebase functions does not use environment variables but instead the functions.config() object. To configure it convenienty create a new JSON file in the following format. (To generate a private/public key pair you can use ssh-keygen):

{
  "steam-login": {
    "discord": {
      "client-id": "client-id",
      "client-secret": "client secret"
    },
    "clients": {
      "my-app": "https://my-app.com/login_return"
    },
    "jwt-config": {
      "jwt-secret": "-----BEGIN RSA PRIVATE KEY-----\n...\n-----END RSA PRIVATE KEY-----\n",
      "jwt-public": "-----BEGIN PUBLIC KEY-----\n...\n-----END PUBLIC KEY-----\n"
    },
    "session-secret": "some random string",
    "steam-api-key": "steam api key",
    "root-url": "root url (e.g. https://my-app.com",
    "firebase": {
      "client_id": "afssdaf",
      "THIS IS YOUR FIREBASE SERVICE ACCOUNT": "FROM https://console.firebase.google.com/project/_/settings/serviceaccounts/adminsdk"
    }
  }
}

Pipe the json to the config generator: cat config.json | node json-to-firebase-config.js

Deploy the function: yarn deploy:firebase

You can then use all of the endpoints against that function. (https://us-central1-project-id.cloudfunctions.net/firebaseSteamLogin/auth/steam?client_id=my-app)

Note: At the moment we cannot use functions.config().firebase as the credentials do not support signing tokens (see also https://stackoverflow.com/questions/42717540/firebase-cloud-functions-createcustomtoken/42724251#42724251)