How to authenticate a java web app with KeyRock? - fiware

Question

We are trying to create a user authentication in our web app ( that we are developing in Java Spring MVC). For our authentication we want to use the token and user info acquired from the users fiware.lab account on global instance of keyrock.
Since Keyrock is based on OAuth2 protocol, what is the best approach to use keyrock from our web app?
Is there a java library that we could use for this purpose?
Is there a way to integrate spring security or apache oltu?
Every example would be more than welecome.
We only have the implementation of node.js but we need a java version of this:
var express = require('express');
var OAuth2 = require('./oauth2').OAuth2;
var config = require('./config');
// Express configuration
var app = express();
app.use(express.logger());
app.use(express.bodyParser());
app.use(express.cookieParser());
app.use(express.session({
secret: "skjghskdjfhbqigohqdiouk"
}));
app.configure(function () {
"use strict";
app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));
//app.use(express.logger());
app.use(express.static(__dirname + '/public'));
});
// Config data from config.js file
var client_id = config.client_id;
var client_secret = config.client_secret;
var idmURL = config.idmURL;
var response_type = config.response_type;
var callbackURL = config.callbackURL;
// Creates oauth library object with the config data
var oa = new OAuth2(client_id,
client_secret,
idmURL,
'/oauth2/authorize',
'/oauth2/token',
callbackURL);
// Handles requests to the main page
app.get('/', function(req, res){
// If auth_token is not stored in a session cookie it sends a button to redirect to IDM authentication portal
if(!req.session.access_token) {
res.send("Oauth2 IDM Demo.<br><br><button onclick='window.location.href=\"/auth\"'>Log in with FI-WARE Account</button>");
// If auth_token is stored in a session cookie it sends a button to get user info
} else {
res.send("Successfully authenticated. <br><br> Your oauth access_token: " +req.session.access_token + "<br><br><button onclick='window.location.href=\"/user_info\"'>Get my user info</button>");
}
});
// Handles requests from IDM with the access code
app.get('/login', function(req, res){
// Using the access code goes again to the IDM to obtain the access_token
oa.getOAuthAccessToken(req.query.code, function (e, results){
// Stores the access_token in a session cookie
req.session.access_token = results.access_token;
res.redirect('/');
});
});
// Redirection to IDM authentication portal
app.get('/auth', function(req, res){
var path = oa.getAuthorizeUrl(response_type);
res.redirect(path);
});
// Ask IDM for user info
app.get('/user_info', function(req, res){
var url = config.idmURL + '/user/';
// Using the access token asks the IDM for the user info
oa.get(url, req.session.access_token, function (e, response) {
var user = JSON.parse(response);
res.send("Welcome " + user.displayName + "<br> Your email address is " + user.email + "<br><br><button onclick='window.location.href=\"/logout\"'>Log out</button>");
});
});
// Handles logout requests to remove access_token from the session cookie
app.get('/logout', function(req, res){
req.session.access_token = undefined;
res.redirect('/');
});
console.log('Server listen in port 80. Connect to localhost');
app.listen(80);
Edit 1
Here is my set up:
and the end result error I get when I call the token:

Answer 1

Fiware devguide explains how this oauth2 flow works against KeyRock.
There also, you can find linked several oauth2 implementations like scribe-data, where you can find several examples on how to use oauth2 authentication against some of the most extended social networks.