I'm writing a single page web app using express and react.
I am now trying to choose the way to authenticate my users.
I want to let them register and log in with email and password and 3rd party provider like Facebook, Google etc...
I read some articles about passport and jwt (express-with-passport, jwt-with-passport), but none of them combined jwt and 3rd party provider.
The only way I could think of is to save the tokens in my db, and for each request to compare them (tokens provided by a 3rd party and tokens generated by myself using jwt)
Saving the token from a provider in my db and compare with each request makes sense, but using jwt I just need to verify the token without accessing the db.
How can I differ the tokens that I receive from the client? How can I tell when to access the db (for provider tokens) and when to verify using jwt?
EDIT:
The way of implementation I was thinking about is as follows:
- Username & password: Upon login, generate a token (using jwt) and send it to the client. Every request will include the token and the server will verify it.
- 3rd party provider: Let's say that the user is authenticated with Facebook. My server receive the token (using passport-js) from Facebook. Now I need to send the client its token. I could send the token I just received from facebook, but then how can I verify the token the client send to me afterward on every request?
So I could generate once again a token using jwt and work just like described above.
Is this a good implementation or am I missing something? I couldn't find
a full tutorial that describe all of those aspects.
Rather than using a token that an identity provider might give you, you might consider generating your own tokens based on a successful login callback to your application. Issue new tokens on every request for sliding expiration, and possibly consider the use of refresh tokens.
In your DB, you could store the authentication method for a given user (Facebook / Google / etc.) when they log in. When you receive a request with an invalid token, query for this auth method from the DB, then redirect them to the respective identity provider for re-authentication.
This will avoid DB lookups for most "normal" JWT validations for your app and gives you the full benefits of the stateless nature of the token.
Related
I would like to give the users a possibility to login with some external oauth2 provider (facebook) in my app. The client's part is running on mobile device in a native app.
I am not sure which of the approaches below should I prefer ?
Should the client send the user's access token by facebook with each request ? At each request backend asks facebook to validate the access token. Based on the validation's result, backend performs authorization and return corresponding result to the client.
Should the backend ask facebook to validate the access token only at user logon, then issue its own access token, return the access token back to the client and client will use this access token at making requests to the server to avoid contacting facebook at each request ?
I have read some questions about how to implement the auth with facebook and most of the devs are using B, but I haven't seen any explanation why is it good/bad to use A ?
What I see as benefits of the solutions:
backend doesn't need to care about issuing, refreshing, validating access tokens since this is done only by facebook's authorization servers.
this solution seems to be more effective, since it does not require to connect to facebook at each request.
Security tokens issued by Facebook are signed with a digital signature. The API server only needs access to the public key to validate the signature. There's no need at all to contact Facebook after the user authenticates.
A reason to issue your own tokens after the user signed in with Facebook could be to add claims to the token. But obviously having your own authorization server comes at a cost. It's up to you to weigh the pros and cons.
If you do decide to have your own authorization server, make sure not to write your own! There are open source options like Thinktecture IdentityServer.
I will vote for option B and here is my explanation,
Your API must authorise the request every time with some auth token , which cannot be external provider token, in such case anyone with an access token (eg: other developers) of other provider can access your api, basically there is no auth here.
When your sever issue access token, it's easy to validate and when needed could be revoked easily (eg: on password reset)
While authenticating , your server has fully control over issuing access token , so the validation is made only once and doesn't have to do every time while calling the API.
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 am building an application which needs to authenticate from another application (via api)which provides response status(success, failure) and an access-token.I need simple authentication where when user supplies correct credentials, I hit the api and save the authentication user name and access-token in session and have a persistent session.I have tried looking passport http and other strategies.But I don't think they serve this use case?Kindly let me know if I am wrong and what is the easy and effective way to achieve this.
You don't need store access-token in session.
The easiest way is use JWT (JSON Web Token) - http://jwt.io. When user sends username\password credentials to your API, you check if these credentials is correct. After that you are signing JWT and respond to the client.
When client sends to you signed access-token, you can check it with passport-jwt module - https://www.npmjs.com/package/passport-jwt.
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.
I have been researching on RESTful authentication alot, and I still can't get a very clear idea, how can I design my web architecture. I have many questions that are unanswered.
I want my API to be served to mobile and web too and I am using Express v4.
I don't want to use Basic Authentication, as many posts have suggested as a simple way out, or I can use the Passport middleware, but I want to use token based authentication or something similar or better,and I want to make my authentication, so I could understand better, but I am not sure how can I achieve it.
I will simplify my intended authentication architecture below:
Registration of a new user
Client side
Post username and password to server
(I know if you want to make the connection secured is to use https connection, or else I will expose my credentials, or you got any other options besides https? or else I will need to use the public and private key with timestamp and hash my credentials before sending to server? How can i do this? Is there any other better option?
Server side
Hashed the password using salt cryptography, and stored the hashed password and salt, then generate a token ID and sent to the client, and the token ID is stored in sessions or using the REDIS database?
Isn't that using sessions violates REST again? But, if I don't use sessions, how can I store the token ID and compare it with the client side?
Client side
Since now I have the token ID, how can I store on client side?
Should I use cookie? If yes, will this violate the RESTful? And how can my mobile application store the cookie too?
What other options can I have besides cookie? I can't think of any.
Authorizing API
Client side
Now, I have the token ID, I will place this in the authorization header each time I would like to make a request to the server.
Server side
When a request is received, the server will check the token API, and compare it with the session token, if it is true, request allow else reject
Is this a standard way for Express application authorization?
I am sorry for the lengthy post, but I feel that I should really master the authentication and authorization because it is important. I do hope someone can correct my misconception of REST authentication and answer my questions or suggest me a better way to do it.
Send the user credentials encoded over https
To compare the token at the client side you can either keep it in map or in Redis store corresponding to user id and match it to consider user authenticated. It does not kills the significance of Rest as in Rest as well authorization tokens are sessions only which after expiry
Express does not have any specific or standard method of authorization , it only enables you to use any db in backend to perform authentication and authorization as required by your application
Your solution is the use JWT tokens for your authentication .You can read more about JWT at https://medium.com/dev-bits/a-guide-for-adding-jwt-token-based-authentication-to-your-single-page-nodejs-applications-c403f7cf04f4
With JWT tokens you can have a token base auth system with no sessions UID at cookies , but you have to implement logic to handle tokens that have sign out something like blacklist tokens.