Using IdentityServer4 as Class Library instead of Hosting Solution - c#

I have been exploring IdentityServer4 for a couple of days. It performs hosting internally generating a connect/token endpoint which internally validates and generates an access token.
Even to call it a discovery URL is needed ultimately requiring a web app template for hosting.
Is it possible to use IdentityServer4 as a library that just allows access tokens to be generated?
**Updated Based on input from Bryan
What I am trying to achieve here is GSMA Compliance that requires both OpenID Connect and OAuth. I need to generate an Access Token as well as Identity_Token. But the caveat here is that IdentityServer4 hosts its internal endpoint where I do have custom endpoints. Also it require http based calling and I do require a sort of library that I can integrate and internally call to generate Access token as well as Identity Token.
** Some more update
We have hosted a custom GSMA compliant Web API Project and have hosted several endpoints as per required by GSMA ultimately validating and sanitizing the request landing on our endpoints. Internally we do require an Access token and Identity Token to be generated and shared back on the callback of the calling party. Currently, I have used an Identity Server template which is MVC based project ultimately requiring us to use at least two ports/project one for our Custom GSMA compliant APIs and one for Identity Server. Calling identity server via URL add a new hop and an HTTP request needs to be sent out to Identity Server whereas I was thinking to use IdentityServer as a class library somewhat allowing me to pass in input parameter and do get an access token/ identity toke.
Upon dissecting server Identity Server project like
Identity Server 4
Identity Mode
Identity Storage
I got the impression that it's very difficult to exact a library out of these projects that can help me generate access token/identity token easily.

IdentityServer4 is an OpenID Connect (and OAuth) identity service -- it's not just about tokens. Those technologies are primarily HTTP-based. Thus IS4 is built on top of ASP.Net Core's web tech. If you just need tokens (JWT, I assume), it's pretty simple to roll your own and use them however you see fit. A few Google searches (or an SO search) will provide you with the code needed to create your own JWTs (for example: https://houseofcat.io/tutorials/csharp/identity/createjwt). Without more information about how you want to use them, I can't elaborate on this answer.

Related

Does ASP.NET Core feature a built-in OAuth2 token exchange?

I'm building an ASP.NET Core application and using FusionAuth as my authentication server. I'm trying to implement this authorization grant workflow, with an SPA using JWT bearer tokens. To summarize, once the user authenticates with FusionAuth, the frontend is supposed to redirect to the backend server with an authorization code. My backend server then needs to receive this code at a special endpoint. Inside this endpoint it will perform a call to FusionAuth again, but this time with the client secret which only the server will possess. In turn, FusionAuth will send back an authorization token in the form of a JWT and a refresh token, which my server then needs to return back to the frontend.
I've looked at the .AddOAuth method, and having read the code it seems capable of performing the token exchange. However, it also has a lot of logic involving challenges and login/logout. This makes me think it's supposed to be used for cookie-based server-side authentication, like you would find with Razor pages.
All I want to do is set up my server to be this authentication intermediary. It looks like .AddOAuth() might do this for me, but it may not be intended for this purpose. I can't find any examples of folks using .AddJwt(...) and .AddOAuth(...) in conjunction. Is there a mechanism in ASP.NET Core that performs the token exchange?
Have you tried using IdentityModel? It's not part of ASP.NET Core, but it is open source. I found it useful when implementing the authorization code grant in ASP.NET core.
Here is some documentation that may be helpful:
https://identitymodel.readthedocs.io/en/latest/aspnetcore/web.html
The short answer is yes - see Introduction to Identity on Asp.NET CORE. There are lots of flavors of OAuth 2, which means it can be configured in many ways. You will need to read the docs.

How to Authorize request from another WebApi project

There are 2 WebApi Projects on different servers. One of these servers (WebApi-A) has OAuth2 authentication workflow setup with Authorization Server and all.
The another WebApi project (WebApi-B) has an end point that I would like to Authenticate through [Authorize] attribute. I don't want have a new authorization server but to utilize (WebApi-A's) authentication process just to validate the token.
From what I understand if the machine-key is same across these server. We can essentially replicate the authentication process from WebApi-A in WebApi-B without having to call WebApi-A at all.
How do I achieve this?
You could, in theory, pass through the JWT token and if your OAuth setup uses the same client secret and data store it should just work. You would have to ensure that you add the JTW token when requesting and to use some distributed cache to verify.
I would rather ask whether or not you should rather create a gateway that can handle and authenticate the requests and delegate them to the separate APIs? This feels like an identity server (http://docs.identityserver.io/en/latest/topics/apis.html) would solve your problem. Anything you do other than moving the authentication from web api A would just be a stopgap.
Duplicating the setup could work but that will mean that you have to now maintain it in two places. So I agree that doing that is less than ideal.
This is a great article that may aid you:
https://www.scottbrady91.com/OAuth/Delegation-Patterns-for-OAuth-20
This will have a lengthy answer so I will just leave you this diagram showing multiple Resource Server, Client, and a separate Authorization Server
Taken from this article Single sign-on across multiple applications (part II) which I hope could get you started.
you can use your token when login in web api and then you add the token to the header "Authorization" with bearer "your token"

Microsoft Identtiy & Identity Server 4 process flow relationships

I'm working on building a series of micro-services using Aspnet Core. A mobile application, desktop application and web-application will consume the services over Http REST APIs.
For user auth, I'm utilizing the Aspnet Core Identity platform, but I'm exposing the creation of user accounts via a REST API. The clients make a REST call with the credential information and my API uses the Microsoft Identity APIs to provision the user. The user would be authorized to hit the individual resource servers with an auth server using IdentityServer4.
I have two questions that I've not been able to find clear guidance on from a security stand-point. Should the Aspnet Core project that utilizes Microsoft Identity for user creation be in an independent Aspnet Core project from the project that handles auth via IdentityServer4? Are there downsides do separating the two out that I need to consider?
The Microsoft Identity API has template and Razor Views that can be used to handle the auth from a server-side perspective, including redirects on account creation or sign-in etc. If I'm doing everything via SPA or Client-side native apps, is there anything wrong with just providing a POST API that accepts the user information, creates the account via UserManager<T> and returns the UserId?
I want to provide a dedicated sign-in page, similar to FB/Google/Twitter etc for Auth to happen across any app that wants to authorize a user for my services. I don't typically see account creation as part of the OAuth process though. Is it typical that you would allow for redirects to an account creation page, that redirects back to a client upon successful account creation or is that process typically just used for Auth via OAuth flows?
I would suggest to consider using one service for IDS4 and ASP.NET Identity since they can be integrated and give you the full functionality you're looking for(auth, and users management).
IDS4 has examples and good documentations regarding that.
To me, I think separating them would be an over engineering.
one example: when IDS4 generate access token for a user, you should get claims, roles and validate username and password, all of that are stored in ASP.NET Identity.
So for more details you can check the docs of Identity Server 4: http://docs.identityserver.io/en/latest/quickstarts/0_overview.html
or it's my pleasure to check my little blog post that I tried to give some more detailed and step by step.
https://feras.blog/how-to-use-asp-net-identity-and-identityserver4-in-your-solution/
Start with IDS4 link because it might be enough :)
The main point when thinking about security management UI is how to secure that UI. And the most safe approach for today is cookie-based auth with same-site cookie (the way, MVC uses by default). Consider that when and if selecting serverless SPA pattern. For management purposes-app having strict backend is much more secure than token-based access to distributed api-s.
Regarding the application hosting, #VidmantasBlazevicius is absolutely right, there is no the only strategy: hosting all the services in one app is simpler, so it better fit lo to middle loaded systems. But with raise of the number of users and authentication requests, you might want to scale, and separating management UI from authentication is one of the ways to handle that.

mvc authentication against web api middle tier

I currently have a web api 2 project acting as my applications middle tier. I need to secure this project as well as provide an authentication service for my MVC project and potentially iOS and Android applications.
The web api business logic requires the checking of the user permissions/roles to ensure security, the mvc project requires the same functionally to ensure the request to the controllers are valid. How do I do this using Asp.net Identity or some other means? Are there any reference projects for this sort of thing?
Some good info here:
http://www.asp.net/web-api/overview/security/authentication-filters
Another way I've seen it done is have a separate API to generate access tokens for a 'transaction' using whatever credentials you want to use...but usually done via https! This token is then passed by the client to the business layer API as a parameter. Various checks can be carried out on the token e.g. Same client that requested token? Token expired? Token already used? Etc
Let me know how you got on.
Thanks.
UPDATE
Web API Security with local accounts:
http://www.asp.net/web-api/overview/security/individual-accounts-in-web-api

How to get started with OAuth to secure a Web API application?

I have a Web API application and I've understood OAuth would be the standard security model for APIs where an Authentication Server would become responsible to generate Authorization Tokens so that the user can send to our server and consume the services.
I'm very new to this but I understand the roles involved:
Resource Owner
Client
Resource Server
Authorization Server
But what is OAuth exactly in practice, not in theory? Is it a .NET library? Is it a service provided by a separate Company? Is it something I can configure on my local development machine and see how it works?
How to get started with OAuth to secure a Web API application?
OAuth is a protocol; the current version is OAuth 2.0. More to your question, that link lists several implementations of the protocol in various technologies. For use with the .NET Web API you're probably interested in DotNetOpenAuth which provides implementations of both OAuth 1 and OAuth 2.
I'm using DotNetOpenAuth in an app I'm working on now to secure a .NET Web API. I've got an OAuth2Handler which extends DelegatingHandler which is inserted into the Web API pipeline before incoming requests reach any controllers. OAuth2Handler does the following:
Instantiates a DotNetOpenAuth ResourceServer
Calls ResourceServer.GetPrincipal() which reads and decrypts an access
token (issued elsewhere by the AuthorizationServer and returns an
OAuthPrincipal (In my case I'm reading additional data that the DotNetOpenAuth implementation allows you to pass and creating a ClaimsPrincipal.)
Assigning the IPrincipal containing the user information read from the access token to the User property of the thread and current HTTP context so it is available from the ApiController.User property in the service controllers: httpContext.User = Thread.CurrentPrincipal = principal;
Honestly, getting this all working (e.g. setting up the authorization server, resource server, certificates, etc.) isn't trivial. Unfortunately there didn't seem to be a good guide on the DotNetOpenAuth site. Here's a few other tasks you'll have ahead of you if you go this route:
Implement IAuthorizationServer - This is the interface provided by
DotNetOpenAuth that allows you to plug in to the library and use
their implementation to issue OAuth2 access tokens. You'll also need to implement INonceStore and ICryptoKeyStore which I did using an EntityFramework context for storage.
Configure Certificates - The AuthorizationServer and ResourceServer each use certificates to encrypt/decrypt the access token ensuring they are only accessible to each other. I built some custom configuration so I could manage this configuration in the web.config files of my authorization server app and my Web API services (resource server).
Manage Refresh Token - When first requesting an access token from the authorization server you'll get back (depending on your configuration) both an OAuth2 refresh token and an access token. The services use the access token which should be short-lived. The refresh token is used to get more access tokens. The refresh token should be kept secret (whatever that means in your scenario). For me it means the refresh token is never exposed to client-side javascript in my web app.
I hope that helps give you a high level idea of how to get started with OAuth and .NET Web API. Here's a blog post demonstrating some of these steps. This SO answer gives a few more high level details of the client side of the picture.
(The DotNetOpenAuth online docs appear to be down right now... sorry for no links to them; Apparently it has happened before).

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