asp.net 5 and IdentityServer4 - asp.net-web-api2

I am working on a prototype for a site re-architecture using ASP.NET 5 and I am debating using IdentityServer4 for my Authentication and Authorization. I have reviewed a lot of samples and articles about setting up IdentityServer3 and 4 and I am trying to wrap my head around if it can handle my client’s requirements in a proper way. Here are my requirements.
I have 3 sites that need authorization. Site 1 (abc.com) will require windows authentication and will be a combination of mvc and webapi calls using roles (or roles converted to claims) for authorization. Site 2 (def.com) is a trusted site that wants a login widget with a username/password/rememberme text box on their site that when submitted will authenticate the user and redirect them to site 3 (xyz.com). Site 3 will also have its own login page and will be a combination of mvc and webapi calls using claims. Site 2 and 3 will not be using windows authentication and the client does not want them redirecting to the identity server login screen, but rather having their own login screen and calling the identity server from code with the credentials to login.
Here are my questions regarding this scenario and IdentityServer4.
Can Idsvr4 handle one client using windows authentication and
another using username/password authentication?
If so, is there a
reason to have windows auth in idsvr4 or should it just use standard
windows auth within the webapp?
Can idsvr4 be setup to have the client collect the username/password/rememberme values and pass them through code to
get the proper jwt tokens for both mvc and webapi?
If so, can it
log them into both the mvc and webapi applications on another site?
If so, is this circumventing the real purpose of identityserver4
and therefor is a bad idea?
If it can handle this scenario and is a good idea, how would I setup the client, scopes and code to handle the login through code and redirect?
Examples are great and very welcome, but I am not even sure what verbiage to use to search for this scenario so even pointing me in the right direction would be of great help.

Not sure if this question is still active. But yes, i believe you can do all that.
1) You can setup which ldp is available for each client by setting IdentityProviderRestrictions on the client (docs)
1.1) - Not sure what you mean, i believe one of the points of having idsrv is to sentralize you authentication, and it makes it easier for future websites to integrate with the same service.
2) When logging in using a client (application), you also specify which apiResource the client has access to - and the application needs to add this to the requested scopes when signing in. So if your client is the mvc application, you just add the ApiResource in the AllowedScopes - and set the request_type to id_token code - this would then give the user a access_token that is passed with each request to the backend api. (docs)
2.1) - This would basically log the user in on both sites - using an access token that says that the user is authorized to use the backend api.
2.2) - In my opinion this flow is one of the things that makes idsrv great - and they even mention this as a great feature of idsrv themself. You just need 1 trip to the authserver to gain access to all systems.
as for pt. 3 - Take an extra look at the docs, try to setup a blank project following the quickstarts.
For logging in from your own login page, you need to use the grant type Resource Owner password - Altough they dont recommend doing this for security issues (transmitting passwords over the wire) - it is supported.

Related

Add user claims after authentication against IdentityServer 4

I have the following projects:
Identity Server 4, with ASP.NET Identity as a user store for all users of all my apps.
.NET Core 5 Web API
Xamarin app
The flow goes like this:
User logins from the Xamarin app (3) and is authenticated against IdentityServer (1)
User receives an access token from Identity Server, that contains the sub claim
User makes a request to the Web API (2) using the access token
The Web API (2) checks its own database for user permissions
----QUESTION/PROBLEM IS HERE-----
Should the Web API add these user claims (permissions) to the access token, OR should the Web API always check the database for the user permissions on every request made from the client?
Maybe I could add the claims before authenticating with IdentityServer, but this would mean that IdentityServer would have access to the Web API's database. I believe this is not a good practice because of separation of concerns.
Another solution would be to introduce a caching mechanism when the Web API validates the token, so that it doesn't always check the database.
Using claims transformation, it is my understanding that I can add the claims to this 1 request only, meaning that the next time a client makes a request, claims transformation should happen again, since it doesn't return a new access token to the user.
Ideally, I would like the Web API to add the claims to the access token so that the Web API can trust these claims on all subsequent requests. I cannot find a way to do so, though. I've searched for Claims Transformation, IssueJwtAsync (IdentityServerTools), IProfileService, but I think none of these are solutions to this problem.
Is this good architecture? Please do share your opinions on this subject and potential solutions.
Thank you very much!
You need to add these permissions in web api, because users need to access the corresponding resources according to these granted permissions. And permissions are granted when the user logs in for the first time, without the need to access the database in every request.
In this case, you can use Claims Transformation. This link has more detailed steps which can solve this problem.

Generating a JWT in an Active Directory environment

I have an ASP.NET Core 2.0 Web API which will run in a very-high security corporate AD environment (no Azure, no Azure AD, which makes Googling for a solution useless).
The API uses JWT auth, and the client will be an Angular 2+ SPA.
What is the easiest way to issue a token?
My initial thought was to set up an authentication endpoint with Windows Authentication that issues the token and populates the claims appropriately.
Is this the best solution?
Or is there another way I can get the JWT token issued without connecting to any external (internet) services?
Working through this exact thing myself. What we have is a local login and a domain login. The local just authenticates to the DB and the Domain authenticates out to an LDAP. Basically what I am doing is issuing the token based off of a positive authentication regardless if it is the LDAP saying its okay or the DB saying its okay. Here is an example for the DB side of it .NET Core JWT Authentication. The LDAP logic itself is the same it always has been with DirectoryServices etc. There are a ton of examples on here and elsewhere for that, but to answer your question directly set the token issuance based off of a good authentication to AD instance. Separate the two logic sets and you should be good to go.

ASP .NET Core Identity default authentication vs JWT authentication

I am developing ASP NET Core Web API and I am confused by choosing the authentication method. I used to apply default Asp Net Identity authentication, but recently I've known about JWT. So I've implemented Authentication almost as it done in this article: https://stormpath.com/blog/token-authentication-asp-net-core.
But I can't understand the benefits of this JWT. With simple Asp Net Identity Authentication, I don't care about token storage etc. I only need to log in with signInManager and use authorized methods until logout. With JWT I need to think about the token store, expiration, and other difficulties. So, what're the benefits of this JWT? How can I store this JWT token after login? Furthermore, should I even use this JWT? In my case, I need simple authentication for simple WebApi which will be used by one or little bit more users. I've also heard about OpenIddict, Auth0, IdentityServer, so what's the difference between all of these authentication mechanisms?
This is the way I understand this, split in to 3 logical parts.
Authentication Server - this will authenticate and issue the JWT token, when the API need's to validate the token it will send the token to this server to validate it.
Client - this is what serves your web pages, or you app perhaps. This is what will need to request and store the the JWT token. The client will need to pass the token to the api every time it requests data.
API - this is what serves the information and needs to validate the token with the Authentication Server.
So, what're the benefits of this JWT?
JWT is issued to the client and stored on the client side. Having JWT allows multiple client's (App's or Websites) use the same authentication server which distributes JWT and states which API's the client's can use and how.
How can I store this JWT token after login?
I only tried to store it in an Ionic 2 app which uses angular 2 which has a storage module. But i'm pretty sure numerous people have done this already and asked this question:
Simple JWT authentication in ASP.NET Core 1.0 Web API
Token Based Authentication in ASP.NET Core (refreshed)
Update
If your front end is made purely html/js/css and doesn't have a back end to accommodate it you would store your token in local storage, there a multiple npm packages that help you with this like this one. You want to look for Implicit flow.
Otherwise if you do have a back end that comes with your front end you want to store the token in a session/database your pick, there are 3rd party providers to do this like IdentityServer4. You want to use Hybrid flow
Furthermore, should I even use this JWT? In my case, I need simple
authentication for simple WebApi which will be used by one or little
bit more users.
The reason for the whole separation of concerns is performance so you don't really need it since it's just one or a little more users. Do it because it's a learning experience, JWT is not easy to setup from the beginning and will require you to do a lot of reading and you will fail and you will be frustrated but at the end you will know how to set it up and how it works
I've also heard about OpenIddict, Auth0, IdentityServer, so what's the difference between all of these authentication mechanisms?
So what you did in the Stormpath tutorial is NOT production ready. That is just a little demo, to help you understand what JWT is and how it works. The above mentioned are complete libraries that tackle all the heavy lifting and do not require you to built the whole thing from scratch. And the main difference between them is the scope that they cover.
I personally used IS4 and it had me crying no more than 2 times (It was simpler than I thought):
http://identityserver4.readthedocs.io/en/release/
https://github.com/openiddict/openiddict-core
https://auth0.com/docs/quickstart/webapp/aspnet-core/00-intro
Use tokens (JWT) if you have multiple applications or services (web, mobile, other services) connection to your API. Benefits: Stateless, Scalability, No cookie, no CORS problems (if you allow it).
If your API will be used by only one web application use the default ASP default authentication system. Its easier to set up.
If you webapi and user interface are hosted in the same web application, token bases security does not buy you anything over the cookie based authentication provided by the built in authentication. That's because the authentication cookie gets sent back to the keep application on every HTTP request. When you make calls to a website other than the one you signed in on those cookies do not get sent. So JSON Web Tokens (JWT) provide a standard format for browser to send identity information to a website when a cookie isn't an option.
If your Web Api is to be accessed by AJAX calls then JWT may be a desired choice, but not mandatory. judging by the description of your app,it seems to me that the default authentication system can serve you well.
Auth2 is the authentication mechanism that enable external login such as Facebook. It is part of the default authentication system, and you need not do much in order to employ it in your app.
OpenIddict sits on top of Auth2. It is part of the default authentication system, and you need not do much in order to employ it in your app. It is the authentication mechanism that enable external login such as Google+
IdentityServer may be used for large Wep Api that is accessed by Ajax calls. As for instance, you can use IdentityServer to authenticate users longing to a front end Angular app.
Once again, the default authentication system can serve you well.
Hope this helps...

RESTFul Authentication with WebAPI

I have a web service built with WebAPI that accepts JSON requests and responds accordingly. The core architecture is built but there isn't any authentication/authorization.
After a lot of googling and poking around sample projects, I'm not sure where to start. I've found a ton of material from 2008 and 2009 but not a whole lot of recent guides/workflows for WebAPI / single page apps. I think the workflow should be as follows:
Check to see if the user is logged in: How can this be done with javascript? Do I send a cookie to my webAPI? If so, do I send that cookie as a parameter in the body of the request?
Let the user log in / register: How is this data encrypted/decrypted? Surely I can't be sending passwords over the wire... is this where SSL comes in?
Provide them with access to what they have rights to access: I think I got this - I can just authorize in the controllers on a per-request basis.
Any info would be awesome.
Basically you need a token based authentication or authorization.
If you are referring to the ASP.NET WebAPI, the following project will be a great place to start:
http://thinktecture.github.com/Thinktecture.IdentityModel.45/
Even if you are not using ASP.NET WebAPI, the following video is a great introduction on how to provide authentication/authorization on RESTful web services:
http://vimeo.com/43603474
To answer some of your questions:
Check to see if the user is logged in: How can this be done with javascript? Do I send a cookie to my webAPI? If so, do I send that cookie as a parameter in the body of the request?
You can use a cookie but I normally use the header in order to avoid common XSRF attacks. Cookies are automatically included whenever a http request is sent from the browser.
is this where SSL comes in?
Yes. If you are going to go ahead with the token based approach, you can use a separate server (Identity Server) to do the authentication for you.
JavaScript clients are unique. Do you have the Web API and the page serving up JavaScript in the same domain? If not, you have same origin policy restrictions. If you have the same Web application hosting the web pages and Web API, you can use forms Authn. In that case, you don't need to send the cookie containing the authentication ticket yourself from JavaScript. Browsers do that for you and that is the cause of XSRF problem. You have to be careful about JavaScript sending credentials that the end user is not supposed to know. If JavaScript knows something, any intelligent end user can get to that knowledge. OAuth 2.0 implicit grant could be a good choice. The end user enters the credentials (password) in the authorization server which issues an access token. JavaScript gets the token and presents it to the web API but it will never have access to the credentials.

Single Page Application Authentication

My company is re-writing its e-commerce site as a single page application using the new Web API / SPA features in MVC 4. We're not sure about the best way how to handle authentication.
Specific questions:
How do we handle both encrypted and non-encrypted communication? Clearly, we need to use HTTPS for the login, account, and checkout AJAX, but we'd like to use HTTP for browsing the catalog in order to avoid expensive SSL handshakes that would slow the whole site down. Is this even possible for a SPA, or are we stuck with HTTPS for everything?
What sort of authentication should we use? Primarily our site will be accessed from a web browser, so cookies may be fine. But down the road, we may want to make a custom iPhone app. Is Basic Authentication, OpenId, or OAUTH preferable? If so, why?
If we go with Forms Auth and cookies, will the redirect issue be fixed for the release of MVC 4, or do I have to use the haack?
If we go with Basic Authentication, how do you do persistent sessions, so that users don't have to log in every time they go to the page again.
Which authentication methods are well supported by ASP.NET MVC 4. It'd be ideal not to have to write a lot of specialized code.
Thanks in advance
1. How do we handle both encrypted and non-encrypted communication? Are we stuck with one protocol, https, with a spa?
You are not stuck with one protocol. With a spa you can use ajax to communicate over http or https, whichever one you choose at any given time. I would use https for anytime your are sending sensitive information like a persons name or their birthdate or login credentials.
Once a user logins to your site over https then your server can set a forms authentication cookie for that user. This cookie should be an encrypted value that ties their session to the server. You must be aware that if the rest of your site is using http then you have the risk of this cookie being passed over the wire in plain text. Even though the contents of the cookie can be encrypted, using an encryption algorithm of your choosing, a malicious person can steal this cookie and jack your user's session.
This might not be a big deal to you though if they are only allowed to browse the site and create a shopping cart. Once the user is ready to checkout then you should re-authenticate the user, over https, as a sort of double check to make sure they are not a malicious user. Amazon does this.
2. What sort of authentication should we use?
Well, that's all a matter of what features do you want your site to have.
OAuth is for exposing webservices which you can allow other sites to call with delegated access. What this means is that if you have a user who wants another site (site x) to be able to access features on your site for their profile. The site x can redirect the user to an oauth endpoint on your site which will authenticate the user. Your oauth endpoint will ask the user if its okay that certain features are shared with site x and if the user agrees a token will be generated. The user passes this token to site x where site x will make server to server calls to your site. Site x will present the token in the calls so the calls to your services will be a delegated access call. OAuth is a way of provisioning other sites to make delegated access to your services. I hope i was able to explain that clearly.. I'm not always good at this.
OpenID is not a very secure way of handling authentication its more of a convenience so that users don't have to be hassled with registering an account with your site. Because OpenID is completely open you are trusting another provider to validate your users. If the third party provider's user store is compromised then your users are compromised also. It's an example of a voucher system where you are basically saying I will trust who you say you are, if you can have an OpenID provider vouch for you.
Another solution is WS-Federation. WS-Federation is if you have multiple sites and you want to have 1 authentication provider that you trust. This authentication provider can be yours and basically all your sites say if you want access to my site then you have to first be authenticated with my authentication provider. This authentication provider can live on a seperate domain and can choose any authentication mechanism it chooses. You are trusting that this auth provider will do its best job to manage your users accounts.
WS-Federation can be overkill though if you only want authentication on your site and don't have multiple sites. In that case I would just recommend doing Forms Authentication and this should be simple enough to do. There are lots of examples of how to do this and microsoft provides many solutions for how to do this. You should look into creating a custom membership provider.
Once a user has been authenticated with your site you should create a forms authentication cookie. This cookie ties the user to their session on the server. This applies to all the scenarios listed above. MVC 4 supports all the scenarios listed above also.
Thanks, and feel free to ask more questions if I wasn't clear enough.
** EDIT 12/1/2017 **
Coming back to this question years later I have learned that relying on cookies for REST based APIs is not a good idea. You don't want to create a session on your web application because it makes your app harder to scale. So, if you need authentication then use HTTPS with some form of authentication (BASIC, DIGEST, Token Based, etc..). So, your SPA client appl will set the Authorization header on every http request and then your web server app will re-authenticate every request.
The main downside of using ASP.NET's form based security is that it assumes you're want a 401 web page when your authentication fails (useless when you're doing an AJAX call) and it's really designed around doing redirects which kind breaks the whole SPA pattern. You can hack around it but it's not designed for the purpose you're using it.
This toolkit may provide an alternative to ASP.NET'as form model.
Not yet sure how mature it is ...
http://www.fluentsecurity.net
Feedback welcome.
I just started working with webapi myself so don't consider my answer authorative. I'm not a security expert though I should be. I ran into the same questions as you did and found, as you did, that there is no authorative answer though - within mvc webapi at any rate. Looking at other webapi specs may give you some inspiration.
The simplest way I came across was of course using SSL. That let's you get away with sending credentials in clear text in the header. Doesn't break rest.
My api will employ SSL all the way but I wanted to double up anyway. So I'm sending an encrypted key in the querystring for all my requests. Pretty much the way cookieless authentication works for a non api asp site, but mvc doesn't play with it so I've rolled my own solution.
On a mobile site, the user would log in, be redirected, to the app with the encrypted key encoded into the js. So he'll initially have a cookiebased auth for the site, and be responsible for it's protection, password saving etc.
Another api consumer would get a more permanent "secret" from a dev site yet to be made and use that to check out a key.
Normally mvc authentication is stateless, meaning the ticket is never invalidated server side. If you controll the client you can just ignore invalidate cookie requests if the server logs you out, and just keep on reusing the ticket. Eventuelly you might want to keep track of your tickets server side, but it's not stateless, doubt if it's restfull, and by consequence scalability taket a hit. But authentication is pretty important so...