jwtsso

JSON Web Token Single Sign-On consumer middleware for Express.

Usage

Setup Express app with jwtsso and session middleware

var express = require("express");
var jwtsso = require("jwtsso");
 
var app = express();
 
app.use(express.cookieParser());
app.use(express.cookieSession({ secret: "secret" }));
app.use(jwtsso({
 
    // Service endpoint that issues the jwt tokens
    authEndpoint: "https://api.authprovider.example/sso",
 
    // Shared secret string with the above service
    sharedSecret: "secret",
 
    // Public mountpoint for this app
    mountPoint: "http://application.example",
 
    // Set max age in seconds for the tokens
    // Defaults to 60 seconds
    maxAge: 120
 
}));

Now from any route or latter middleware you can call res.requestJwt() to get a JWT token from the authEndpoint. The token will be saved to req.session.jwt.

For example to ensure that JWT token is always present you can add following additional middleware

app.use(function(req, res, next){
    if (!req.session.jwt) return res.requestJwt();
    next();
});

By default res.requestJwt([custom path]) will redirect back to same url where it was called from or you can pass in a custom path.

Authentication endpoint

Under the hood call to res.requestJwt() on /current/path redirects user to

https://api.authprovider.example/sso?return_to=http%3A%2F%2Fapplication.example%2Fcurrent/path

From there authentication endpoint is expected to redirect user back to url specified in the return_to query value with the JWT token

http://application.example/current/path?jwt=<token>

jwtsso then detects JWT token in the query string, validates it, sets it to req.session.jwt and clears it from the url bar with an additional redirect.

This module was designed for the Single Sign-On feature of puavo-rest

https://github.com/opinsys/puavo-users/blob/master/rest/doc/SSO.md