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@steelx
Created Jul 28, 2020
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Node js AUTH middleware
const express = require('express');
const cors = require('cors')({origin: true});
const cookieParser = require('cookie-parser')();
// API
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 = async (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.status(403).send('Unauthorized');
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.status(403).send('Unauthorized');
return;
}
try {
const decodedIdToken = await admin.auth().verifyIdToken(idToken);
console.log('ID Token correctly decoded', decodedIdToken);
req.user = decodedIdToken;
next();
return;
} catch (error) {
console.error('Error while verifying Firebase ID token:', error);
res.status(403).send('Unauthorized');
return;
}
};
app.use(cors);
app.use(cookieParser);
app.use(validateFirebaseIdToken);
app.get('/hello', (req, res) => {
res.send(`Hello ${req.user}`);
});
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