I am trying to make Firebase authentication work on the server.
'use strict';
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();
const express = require('express');
const bodyParser = require('body-parser');
const cookieParser = require('cookie-parser')();
const cors = require('cors')({origin: true});
//const expressSanitizer = require('express-sanitizer');
const app = express();
// Express middleware that validates Firebase ID Tokens passed in the Authorization HTTP header.
// The Firebase ID token needs to be passed as a Bearer token in the Authorization HTTP header like this:
// `Authorization: Bearer <Firebase ID Token>`.
// when decoded successfully, the ID Token content will be added as `req.user`.
const validateFirebaseIdToken = (req, res, next) => {
console.log('Check if request is authorized with Firebase ID token');
if ((!req.headers.authorization || !req.headers.authorization.startsWith('Bearer ')) &&
!(req.cookies && req.cookies.__session)) {
console.error('No Firebase ID token was passed as a Bearer token in the Authorization header.',
'Make sure you authorize your request by providing the following HTTP header:',
'Authorization: Bearer <Firebase ID Token>',
'or by passing a "__session" cookie.');
res.redirect("/login");
return;
}
let idToken;
if (req.headers.authorization && req.headers.authorization.startsWith('Bearer ')) {
console.log('Found "Authorization" header');
// Read the ID Token from the Authorization header.
idToken = req.headers.authorization.split('Bearer ')[1];
} else if(req.cookies) {
console.log('Found "__session" cookie');
// Read the ID Token from cookie.
idToken = req.cookies.__session;
} else {
// No cookie
res.redirect("/login");
return;
}
admin.auth().verifyIdToken(idToken).then((decodedIdToken) => {
console.log('ID Token correctly decoded', decodedIdToken);
req.user = decodedIdToken;
return next();
}).catch((error) => {
console.error('Error while verifying Firebase ID token:', error);
res.redirect("/login");
});
};
app.use(bodyParser.urlencoded({ extended: true }));
app.use(express.static("/public"));
app.use(cors);
app.use(cookieParser);
//app.use(expressSanitizer());
//app.use(validateFirebaseIdToken);=
app.set("view engine", "ejs");
// This HTTPS endpoint can only be accessed by your Firebase Users.
// Requests need to be authorized by providing an `Authorization` HTTP header
// with value `Bearer <Firebase ID Token>`.
exports.app = functions.https.onRequest(app);
app.post("/login", (request, response) => {
var idToken = request.body.token;
console.log("REQUEST BODY = " + idToken);
response.header("Authorization" , "Bearer " + idToken);
return response.redirect("dashboard");
});
app.get("/dashboard", validateFirebaseIdToken, (request, response) => {
response.redirect("/dashboard/new");
});
In the /login POST route, I am receiving the idToken as expected (and showed in the logs). It seems though, that the response is unable to preserve/maintain the header property Authentication: Bearer <Firebase ID token> set beforehand.
In fact, I sent a GET request in Postman to /dashboard by getting the idToken printed by the logs and setting it in the header of the request like Authorization: Bearer <idToken> and it worked perfectly.
Here it says that redirects are in fact new HTTPS requests and therefore don't preserve the header set in the response. What should I do in this case?
