gistfile1.js

var oauth = new (require('oauth').OAuth)(
     'https://api.twitter.com/oauth/request_token',
     'https://api.twitter.com/oauth/access_token',
     'qnNRwjeo8zFjhIDfgG1F6Q',                     // CONSUMER_KEY (replace)
     'JtKRv1e9QIEG6mKvWl0g4ygGVGzWclgfd7GaSBEGtg', // CONSUMER_SECRET (replace)
     '1.0',
     'http://127.0.0.1:3000/signin/twitter', // callback URL
     'HMAC-SHA1'
 );

 app.get('/signin/twitter', function(req, res) {
     var oauth_token    = req.query.oauth_token;
     var oauth_verifier = req.query.oauth_verifier;
     if (oauth_token && oauth_verifier) {
         console.log("##", oauth_token, oauth_verifier);
         oauth.getOAuthAccessToken(
             oauth_token, null, oauth_verifier,
             function(error, oauth_access_token, oauth_access_token_secret, results) {
                 if (error) {
                     res.send(error, 500);
                 } else {
                     // req.session.user = results.screen_name;
                     console.log("@@@", oauth_access_token, oauth_access_token_secret);
                     res.end(oauth_access_token + " " + oauth_access_token_secret);
                     // res.redirect('/');
                 }
             }
         );
     } else {
         oauth.getOAuthRequestToken(function(error, oauth_token, oauth_token_secret, results) {
             if (error) {
                 res.send(error, 500);
             } else {
                 req.session = {
                     oauth_token: oauth_token,
                     oauth_token_secret: oauth_token_secret,
                     request_token_results: results
                 };
                 res.redirect('https://api.twitter.com/oauth/authorize?oauth_token=' + oauth_token);
             }
         });
     }
 });