how the authorization token that is sent back after a user is authenticated is stored in browser and can be used for authorization in the same api for other routes until the token is deleted from the user's database after he logs off?
I used the postman for same. And there in the Headers section i got the authorization token as a response header. But how does this all work in a real login page in the browser?
For storing the token in browser you can use cookie or browser web storage (localStorage/sessionStorage). see this link for browser web storage. For those routes which need authorization you should send back the token in a header or cookie. this blog post may help you more.
Hello you can check this sample OAuth2 based on oauth2-server you can find the repo here: https://github.com/gerardabsi/NodeJS-OAuth2
Some intro,
The Authorization token is JWT usually and is created with some secret key at the server, the library like https://www.npmjs.com/package/jsonwebtoken is used mostly in NodeJs. One can use different strategies using Passport JS to make it more secure and open for 3rd party integration (like Google, FB etc).
Now your question,
When the user initially logs into the system using his valid credentials, the server generate a JWT token with secret key and sends it in the response header. The client side (browser) saves this token in the cookie or local storage, and for the next request sends this token in the request header. The server has the secret key and can verify the token's validation and can proceed or decline the request.
One should ideally use a token that expires in 1 hour (depends on use case) or so and not use non-expiring or long expiry tokens for security reasons.
This is roughly how it works, please let me know if any doubt.
Related
First of all sorry if this subject already exists. I have problem with jwt token. I got register/login system in nodejs with mongodb. After I login (at localhost:3000/auth/login), my token is generated, but when i try to access another page (ex. localhost:3000/priv) it responds access denied. It look like the token has to pass with new request to another page, but how?
Jwt token doesn't work like cookies in the browser
You've to manually store the token to the localStorage or other storage in frontend after login & then attach that jwt token accessing from localStorage to Authorization header while requesting to another route
You can learn this entire process from https://auth0.com. They've a great tutorial on it. Also learn about access-token & refresh-token mechanism to ensure better security
I'm writing an application with a front end in emberjs and backend/server-side in a nodejs server. I have emberjs configured so that a user can login/signup with an 3rd party Oauth (google, twitter, Facebook). I have a backend written in express nodejs server that hosts the RESTful APIs.
I do not have DB connected to emberjs and I don't think I should anyways since it's strictly client side code. I'm planning on using JWT for communicating between client side and server side. When a user logins with their oauth cred, I get a JSON object back from the provider with uid, name, login, access_token and other details.
I'm struggling with picking a strategy on how to handle user signup. There is no signup process since it's OAuth. So the flow is if the user is not in my db, create it. I do not support email/password authentication. What would be the flow when a user signs in with an OAuth provider for the first time? Should emberjs send all the details to the backend on every sign in so that backend can add new users to the db?
What should be part of my JWT body? I was thinking uid and provider supplied access token. One issue I can think of here is that provider specific access token can change. User can revoke the token from provider's site and signs up again with emberjs.
I'm open to writing the front-end in any other javascript client side framework if it makes it easier.
If we're talking about not only working but also secure stateless authentication you will need to consider proper strategy with both access and refresh tokens.
Access token is a token which provides an access to a protected resource.
Expiration here might be installed approximately in ~1 hour (depends on your considerations).
Refresh token is a special token which should be used to generate additional access token in case it was expired or user session has been updated. Obviously you need to make it long lived (in comparison with access token) and secure as much as possible.
Expiration here might be installed approximately in ~10 days or even more (also depends on your considerations).
FYI: Since refresh tokens are long lived, to make them really secure you might want to store them in your database (refresh token requests are performed rarely). In this way, let's say, even if your refresh token was hacked somehow and someone regenerated access/refresh tokens, of course you will loose permissions, but then you still can login to the system, since you know login/pass (in case you will use them later) or just by signing in via any social network.
Where to store these tokens?
There are basically 2 common places:
HTML5 Web Storage (localStorage/sessionStorage)
Good to go, but in the same time risky enough. Storage is accessible via javascript code on the same domain. That means in case you've got XSS, your tokens might be hacked. So by choosing this method you must take care and encode/escape all untrusted data. And even if you did it, I'm pretty sure you use some bunch of 3rd-party client-side modules and there is no guarantee any of them has some malicious code.
Also Web Storage does not enforce any secure standards during transfer. So you need to be sure JWT is sent over HTTPS and never HTTP.
Cookies
With specific HttpOnly option cookies are not accessible via javascript and are immune to XSS. You can also set the Secure cookie flag to guarantee the cookie is only sent over HTTPS.
However, cookies are vulnerable to a different type of attack: cross-site request forgery (CSRF).
In this case CSRF could be prevented by using some kind of synchronized token patterns. There is good implementation in AngularJS, in Security Considerations section.
An article you might want to follow.
To illustrate how it works in general:
Few words about JWT itself:
To make it clear there is really cool JWT Debugger from Auth0 guys.
There are 2 (sometimes 3) common claims types: public, private (and reserved).
An example of JWT body (payload, can be whatever you want):
{
name: "Dave Doe",
isAdmin: true,
providerToken: '...' // should be verified then separately
}
More information about JWT structure you will find here.
To answer the two specific questions that you posed:
What would be the flow when a user signs in with an OAuth provider for
the first time? Should emberjs send all the details to the backend on
every sign in so that backend can add new users to the db?
Whenever a user either signs up or logs in via oauth and your client receives a new access token back, I would upsert (update or insert) it into your users table (or collection) along with any new or updated information that you retrieved about the user from the oauth provider API. I suggest storing it directly on each users record to ensure the access token and associated profile information changes atomically. In general, I'd usually compose this into some sort of middleware that automatically performs these steps when a new token is present.
What should be part of my JWT body? I was thinking uid and provider
supplied access token. One issue I can think of here is that provider
specific access token can change. User can revoke the token from
provider's site and signs up again with emberjs.
The JWT body generally consists of the users claims. I personally see little benefit to storing the provider access token in the body of a JWT token since it would have few benefits to your client app (unless you are doing a lot of direct API calls from your client to their API, I prefer to do those calls server-side and send my app client back a normalized set of claims that adhere to my own interface). By writing your own claims interface, you will not have to work around the various differences present from multiple providers from your client app. An example of this would be coalescing Twitter and Facebook specific fields that are named differently in their APIs to common fields that you store on your user profile table, then embedding your local profile fields as claims in your JWT body to be interpreted by your client app. There is an added benefit to this that you will not be persisting any data that could leak in the future in an unencrypted JWT token.
Whether or not you are storing the oauth provider supplied access token within the JWT token body, you will need to grant a new JWT token every time the profile data changes (you can put in a mechanism to bypass issuing new JWT tokens if no profile updates occurred and the previous token is still good).
In addition to whatever profile fields you store as claims in the JWT token body, I would always define the standard JWT token body fields of:
{
iss: "https://YOUR_NAMESPACE",
sub: "{connection}|{user_id}",
aud: "YOUR_CLIENT_ID",
exp: 1372674336,
iat: 1372638336
}
For any OAuth workflow you should definitely use the passportjs library. You should also read the full documentation. It is easy to understand but I made the mistake of not reading the the whole thing the first time and struggled. It contains OAuth Authentication with over 300 Providers and Issuing Tokens.
Nevertheless, if you want to do it manually or want a basic understanding, here is the flow that I'd use:
Frontend has a login page listing Sign-in with Google/Facebook etc where OAuth is implemented.
Successful OAuth results in a uid, login, access_token etc. (JSON object)
You POST the JSON object to your /login/ route in your Node.js application. (Yes, you send the whole response regardless if it's a new or existing user. Sending extra data here is better than doing two requests)
The backend application reads the uid and the access_token. Ensure that the access_token is valid by following (https://developers.facebook.com/docs/facebook-login/manually-build-a-login-flow#checktoken) or asking for user data from the provider using the access token. (This will fail for invalid access token since OAuth access tokens are generated on a per app/developer basis) Now, search your backend DB.
If the uid exists in the database, you update the user's access_token and expiresIn in the DB. (The access_token allows you to get more information from Facebook for that particular user and it provides access for a few hours usually.)
Else, you create a new user with uid, login etc info.
After updating the access_token or creating a new user, you send JWT token containing the uid. (Encode the jwt with a secret, this would ensure that it was sent by you and have not been tampered with. Checkout https://github.com/auth0/express-jwt)
On the frontend after the user has received the jwt from /login, save it to sessionStorage by sessionStorage.setItem('jwt', token);
On the frontend, also add the following:
if ($window.sessionStorage.token) {
xhr.setRequestHeader("Authorization", $window.sessionStorage.token);
}
This would ensure that if there is a jwt token, it is sent with every request.
On your Node.js app.js file, add
app.use(jwt({ secret: 'shhhhhhared-secret'}).unless({path: ['/login']}));
This would validate that jwt for anything in your path, ensuring that the user is logged-in, otherwise not allow access and redirect to the login page. The exception case here is /login since that's where you give both your new or unauthenticated users a JWT.
You can find more information on the Github URL on how to get the token and to find out which user's request you are currently serving.
I've been working with JSON Web Tokens and reading up on how to make an app more secure. When a user is a authorized, the token is signed, and a token will be placed in the Authorization Header. This token can then be placed in localStorage, sessionStorage, or cookieStorage. The last option came out top to be the most secure option, but I was wondering if any features of a JSON web token, or any middleware, or perhaps JSON Web Encryption (not really sure how this works) that would prevent a malicious attacker from intercepting/grabbing that token, and using it for future requests to the app's APIs, since all that's needed is a request with that token for a dumb server to respond for the information requested.
How can you provide example for refresh node js auth token? I mean by what the parameters can I refresh auth token? For example if I can refresh it by login and password then where should I store this params for single-page app? As I understand store it in cookie is not good idea for security, localstorage is not good also because some of browsers not supported it. So maybe someone know another way for refresh token?
Cookies are a very secure storage mechanism, if used correctly. Local storage should never be used for authentication information. OWASP has a great write-up on storage security:
https://www.owasp.org/index.php/HTML5_Security_Cheat_Sheet#Storage_APIs
To quote the important parts:
Do not store session identifiers in local storage as the data is always accessible by JavaScript. Cookies can mitigate this risk using the httpOnly flag.
[With local storage] There is no way to restrict the visibility of an object to a specific path like with the attribute path of HTTP Cookies, every object is shared within an origin and protected with the Same Origin Policy. Avoid host multiple applications on the same origin, all of them would share the same localStorage object, use different subdomains instead.
Back to your original question: where to store the refresh token? Answer: In a HttpOnly cookie. This prevents the cookie from being stolen by XSS attacks, and it makes it very easy for your server to issue new access tokens (using the refresh token) because the server will have access to both at the same time, on the same request.
You can add another layer and encrypt the entire refresh token that is stored in the cookie.
Caution: when using cookies, you also need to protect yourself against CSRF attacks
I’ve written at length about front-end security and JWTs in these two blog posts:
Token Based Authentication for Single Page Apps (SPAs)
https://stormpath.com/blog/build-secure-user-interfaces-using-jwts/
Disclaimer : I work at Stormpath, our service gives you a secure, hosted user database with many features. Our express-stormpath module makes it very easy to get started with login and registration flows for your application. We are in the process of writing a new release, and it will be using access tokens in the way that I describe in this answer.
I created AuthToken model that contain these fields:
user_id, access_token, refresh_token, access_token_expiration
After successful user login, server side will send refresh_token and access_token to client side and store it to localstorage(cookies for old browsers).
And all subsequent requests will be sent with access_token(I use header x-access-token for $httpProvider in angular).
When token expires, client needs to send refresh_token for updating access_token, refresh_token and expiration date. Since I use sockets I can refresh access_token if it is expired in any request(for this I send z-refresh-token header also for each request) so I shouldn't send any extra request and I can keep current user request, just will return tokens via socket event after it was updated.
Hope this helps
I'm trying to build a mobile app that has a login functionality with an ASP.NET web api, and I need to implement the token based authentication,
what I need is, as a first time the user login using username and password, a new token will be generated with expire date along with a refresh token, I'm thinking of the refresh token because the user doesn't have to login every time the token expires,
the token is saved in the mobile device and in the database, so with each request, sends the token whether in the request header or with the posted data,
I don't exactly know how the token based authentication works in terms of sending the token encrypted or hashed to the user and processing the request in the server
Edit:
an attacker in the middle can just read the token and start sending requests to the server using the token. I mean he doesn't need to know what the token actually means.
I created a class that has these properties (UserID,Token, RefreshToken, ExpiryDate), but I read that it is not a good approach,
I'm using AES for encryption and SHA256 for hash
Thank you for you help,
Please see the following articles in order to understand how token based authentication works in ASP.NET Web API.
http://www.codeproject.com/Tips/821772/Claims-And-Token-Based-Authentication-ASP-NET-Web
http://bitoftech.net/2014/06/01/token-based-authentication-asp-net-web-api-2-owin-asp-net-identity/
Search OpenID and OpenID Connect specs, they will tell you exactly how the tokens should work in your case (non-confidential implicit client flow). You can add OpenID endpoints easily to your asp.net web api if you don't want to use an external openid server.