checking Jwt token on every request? - node.js

Question

I am developing a android aplication with nodejs and postgreSQL, at the moment i just have the login and the register.
When i do a login and everything is fine the server send me a token, that token is stored on the device SharedPreference, now my confusion is, do i need to decode this token on every request, or do i need to do it just 1 time?
in this tutorial at the end, he decodes on every route the token, but i don't need to do that when i do for example a request to register.
What is the best way to implement this?
here is my server code:
//****************************************************Begin of login request **********************************/
router.post('/login', function (req, res, next) {
if (JSON.stringify(req.body) == "{}") {
return res.status(400).json({ Error: "Login request body is empty" });
}
if (!req.body.username || !req.body.password) {
return res.status(400).json({ Error: "Missing fields for login" });
}
// search a user to login
User.findOne({ where: { username: req.body.username } }) // searching a user with the same username and password sended in req.body
.then(function (user) {
if (user && user.validPassword(req.body.password)) {
//return res.status(200).json({ message: "loged in!" }); // username and password match
var payload = { user: user };
// create a token
var token = jwt.sign(payload, 'superSecret', {
expiresIn: 60 * 60 * 24
});
// return the information including token as JSON
res.json({
success: true,
message: 'Enjoy your token!',
token: token
});
}
else {
return res.status(401).json({ message: "Unauthorized" }); // if there is no user with specific fields send
}
}).catch(function (err) {
console.error(err.stack)
return res.status(500).json({ message: "server issues when trying to login!" }); // server problems
});
});
//****************************************************End of Login request **********************************/
//****************************************************Begin of register request******************************/
router.post('/register', function (req, res, next) {
if (JSON.stringify(req.body) == "{}") {
return res.status(400).json({ Error: "Register request body is empty" });
}
if (!req.body.email || !req.body.username || !req.body.password) {
return res.status(400).json({ Error: "Missing fields for registration" });
}
var password = User.generateHash(req.body.password);
User.create({
username: req.body.username,
email: req.body.email,
password: password
}).then(function () {
return res.status(200).json({ message: "user created" });
}).catch(function (err) {
return res.status(400).send({ message: err.message }); //
}).catch(function (err) {
return res.status(400).json({ message: "issues trying to connect to database" });
})
});
//****************************************************End of register request **********************************/
module.exports = router;

Answer 1

If you don't want to use JWT token check for all routes, you can skip those routes.
const url = require('url');
apiRoutes.use((req, res, next) => {
const path = url.parse(req.url).pathname;
console.log(path);
//No JWT token check
if (/^\/register/.test(path)) {
return next();
}
return jwtTokenValidate();
});
function jwtTokenValidate() {
// check header or url parameters or post parameters for token
var token = req.body.token || req.query.token || req.headers['x-access-token'];
// decode token
if (token) {
// verifies secret and checks exp
jwt.verify(token, app.get('superSecret'), function(err, decoded) {
if (err) {
return res.json({ success: false, message: 'Failed to authenticate token.' });
} else {
// if everything is good, save to request for use in other routes
req.decoded = decoded;
next();
}
});
} else {
// if there is no token
// return an error
return res.status(403).send({
success: false,
message: 'No token provided.'
});
}
}