sending the regenerated session-id back to user agent after login with user object in nodejs

Question

I am re-generating the session-id after the user logs-in,the new session id gets generated and i am also saving that session-id in mongodb but the issue is how do i send the re-generated session-id back to the user-agent(browser) with the user object. I have already tried:

res.cookie('sessionId',req.session);
res.json(user);

I am re-generating session-d like this:

let session = req.session;
console.log("printing old session");
console.log(req.sessionID);

req.session.regenerate(function(err) {

if (err)     console.log(err);
else{
console.log("printing new session");
console.log(req.sessionID);

let prev_session = session;
//Copying Prev Session Data to current session.
for (let i in prev_session) {

req.session[i] = prev_session[i];

}
req.session.save();

}
}) 

the above code returns the user object with session-id in header as :

set-cookie: sessionId=j%3A%7B%22cookie%22%3A%7B%22originalMaxAge%22%3A86400000%2C%22
expires%22%3A%222018-07-10T06%3A16%3A16.703Z%22%2C%22secure%22%3Afalse%2C%22httpOnly%22%3Atrue%2C%22
path%22%3A%22%2F%22%7D%2C%22_csrfSecret%22%3A%22fYvLa6exta46VA%3D%3D%22%2C%22passport%22%3A%7B%22
user%22%3A%225b1fcebb293e95fc28cafc97%22%7D%7D; Path=

with this previous sessionid :

set-cookie: sessionId=s%3AZ4HI3m3LzPcxRlp8HVEb4YzIGq3FuZbC.07kibg%2FguTNBTPlO5%2BTfHSkDh7GcQEzenlSqODetvb8; 
Path=/; Expires=Tue, 10 Jul 2018 06:16:29 GMT; HttpOnly

still i am unable to see the updated session-id in session cookie of my chrome browser

My backend is powered by express and passport.

can anyone please help me in this...i have already spend a lot in browsing this issue and have'nt got any working solution.

Thanks in adavnce.

Answer 1

I'm not entirely sure why are have sessionId, req.sessionID, req.session in your code, because all of them are different things.

Using cookie-parser:

Write cookie:

res.cookie('myCookieName',myValue)

Read cookie:

req.cookies.myCookieName

If your new regenerated session ID is in req.sessionID then use that while setting the cookie and not req.session

I have a basic example that should guide you for your implementation:

const express = require('express'),
    cookieParser = require('cookie-parser');

const app = express();

var i =0;
app.use(cookieParser());

app.get('/', (req, res) =>{ 

    console.log("Previous cookie: ",req.cookies.sessionId);
    res.cookie('sessionId',{i:++i, maxAge: 900000, httpOnly: true });
    res.send('Hello World!')});

app.listen(3000, () => console.log('Example app listening on port 3000!'));

This will print the cookie sent in the request, and then send back a new one. In every request, you will see a different number printed on the node console.