Active Directory Authentication in .NET Core Web API - asp.net-core

I am working on an intranet application which consists of a .NET Core Web API back end and a completely separate AngularJS SPA that queries it. A requirement of the project is authentication via AD (LDAP possible.) However, after studying for a while, I cannot seem to find a way for my backend API to receive a username/password and ask AD if it's correct, and what groups they are in, then store that locally and hand off a token to the SPA to use in future requests. Any ideas would be appreciated, thank you.
Note: The web app hands the password to the API in an encrypted format, the API decrypts it, and thats where I'm at.

Related

How to configure JWT in .NET 5 Web API

I have a confusion in while doing development. I am working on .NET 5 Web API in which I have implemented JWT authentication. Then I got to know that, client application(it entire different project owned by other team in my same organization) is configured using Windows AD or SSO, not fully sure though. But still client application won't be sending userid and password in a post request which I have in my AuthController. In this case, how my APIs requests will be authenticated to check if the client has access to it or not.
Any guidance on this would be helpful. Thanks in advance.

ASP.NET Core / Blazor / Web API : how to securely store user data?

I hope its possible someone can point me in the right direction. This is 100% a education issue.
Problem
I need to create a web application at the moment I would like to use with ASP.NET Core MVC or Blazor Server. But I would like to move this to either a Blazor Web Assembly or Angular application in the future.
I am creating what seems to be a very simple web application. Users can sign up and request a licence key. Users can have multiples of these keys. Once a form is filled in this is then awaiting authorization. This part isn't the problem.
I am finding it hard to work out how to and the best way to get this data stored in a database. The licences will be linked to the user stored in the Identity database. I have followed multiple tutorials and tech papers online on how to use authorisation and authentication but none seem to go into details about storing user data. Obviously only the logged in user can view/create their licences and will have no access to anyone else's.
I understand the process will be different for ASP.NET Core MVC/Blazor server and Angular/Blazor WA as these will require an API.
I hope that someone can point me in the right direction as I have been scanning online for 3 days now and kind of need to be put out of my misery.
Thanks in advance.
Below is one of the way to handle.
Create a table with UserId, license, Active, and any other required fields.
Expose a Web API Controller with the Authorize attribute. Only the users with valid JWT tokens will be able to access this Controller.
UserLicensesController will be talking to the table which stores the Licenses.
Use Blazor Web Assembly, OR Angular, OR React JS. Login with valid credentials.
Invoke the Get/Post/Put methods from UI to UserLicensesController Web API, and pass the JWT token.
Please let me know if you need any further assistance.
[19-May-2021] Here is a basic solution.
I have created a basic solution.
UserMgmtStore.sqlproj contains the Database Project.
UserMgmt.API.csproj contains the Web API with JWT authentication.
I am using Auth0 for the authentication and authorization platform.
UserMgmt.Web.csproj contains the Blazor Web Assembly Project.
I have used the Username and Password to retrieve the JWT token from Auth0.
As each individual project with have their own Identity/STS system. I have hard-coded the token just to complete the Proof Of Concept.
I have checked in the POC into my GitHub Repository.
URL: https://github.com/vishipayyallore/mini-projects-2021/tree/master/Projects/UserLicenses

Azure AD or IdentityServer with Web API, understanding the concepts

Be warned possibly noob question ahead.
I'm a little unsure where exactly Azure AD or IdentityServer is supposed to fit in in the overall communication flow.
Here is a scenario that I often face.
Some "dumb" client (e.g. a Windows App that can't use external assemblies or some JavaScript in a web app) has to contact my Web API which will then contact other APIs or other resources.
If I want to try and implement either Azure AD or IdentityServer as a means of authentication and authorization in the Web API, I don't see that this can be done in any other way, than it has to be the Web API that communicates with Azure AD or IdentityServer as the client doesn't have the ability to do so due to the lack of required assemblies.
If this assumption is not correct, then how would I do this?
If it is correct however, then what means of security is there between the client and the Web API other than communicating over HTTPS when the client has to send it's credentials to the Web API, so the Web API can authenticate and authorize the user against either Azure AD or IdentityServer?
If I understand your requirements correctly, then you are able to change the client Windows app, but unable to add external assemblies to it? So you would not be able to add the ADAL NuGet package to it.
You can still use Azure AD authentication - it is possible, but not trivial, to implement the client code yourself.
Or you can, as you already mentioned, pass the user's credentials to the Web API somehow, and then use that to have the Web API do authentication towards Azure AD on behalf of the user. There is a sample app which shows how to use username/password credentials.
This however, goes against the whole OAuth/OpenIdConnect mindset, where your app should never know the user's credentials.
Here:
https://github.com/MicrosoftDocs/azure-docs/blob/master/articles/active-directory/develop/active-directory-v2-protocols-oidc.md
Be careful with trying to use the most recent version of the Azure AD endpoint (just don't use version 2.0, they shot themselves in the foot by excluding all Azure AD webapp registrations & by "securing" web APIs by making them only available to apps with the same appid - as far as I'm concerned, it's unusable until they fix those two issues) - see the "[!NOTE]" near the top of that linked page for the v2.0 limitations.

IdentityServer4 with optional External ADFS for some client configurations

So we are using IdentityServer4 for our web applications, all is good.
We have a new requirement from a client to allow them to perform SSO via their ADFS system using WsFederations, we already provide this for another one of our older web applications that is not tied into IdentityServer4 yet.
Ideally we would like to tie WsFedereration into IdentityServer4 so it is in one place.
Does anyone know if it possible to use IdentityServer4, so we redirect to IdentityServer4, identity that this particular client (possibly via an alternative URL), then IdentityServer4 authenticates against ADFS, collects the claims (probably basic, e.g. email/username/etc) , and we then supplement them with additional claims for access, and pass back to the web application.
What I'm trying to achieve ideally is to not change the existing Web Application, and to sort the plumbing at IdentityServer4, and the Web Application wouldn't know or care if this user was IdentityServer4 only or
IdentityServer4 + WsFederation. This would be useful for other clients across our applications to easily integrate in the future.
Alternatively I could deploy another version of the Web Application that authenticates directly with my clients ADFS system. However this seems a waste of server resources/maintenance for just one small client.
I had a look at the external options (where you click google on or near the IdentityServer4 Login Screen), is there a way to automatically redirect to the ADFS without event seeing the IdentityServer4 implemented Login screen.
Is this possible?
Thanks,
Jon
This was released 2017, see the example at
https://github.com/IdentityServer/IdentityServer4.WsFederation

Browser and Webserver api authentication tokens

I am currently working on a solution that includes a multi tenant webApi which will be accessed by multiple clients, some of which i will be creating, some of which others will be creating.
Access to the api will be available via an ApiKey & Secret (enough for some resources) as well as username & password (for owner resources).
At the moment, the clients i have created (.Net MVC Web apps) have their own membership systems so what happens is the user of the client logs into the client system and the client system passes the login information to the Api to retrieve an authentication token.
The client membership system is really an unneeded abstraction. What i really want to do is have the user log directly into the api and the api pass back an authentication token that can be used from the browser as well as the .Net MVC client app.
My question is, what it the best way to achieve this. In my mind i seem to be struggling with 2 solutions.
1) Have a browser based login (ajax/AngularJS for instance) solution that calls the api to retrieve a token which then passes that token onto the MVC client where it will be stored (session variable maybe). Any future calls to the api that come from the .Net MVC client can pass the token on. This seems wrong to me though. I'm not even sure this is possible.
2) Utilise one of the OAuth flows so that the browser based login can call the API and retrieve a token, and the OAuth flow redirects to the MVC client which then stores the token for that user (again, in a session variable).
The Api was generated using the VS2013 WebApi template using Owin local accounts and is generating tokens via the ValidateClientCredentials and ValidateResourceOwnerCredentials flows, but i think i need to use one of the other OAuth flows for this scenario.
I understand that another solution would be to bypass the .Net MVC client code and create a completely browser based solution using knockout or AngluarJS but it's quite a complex system and i don't really have time to do this at the moment so i'm looking for a solution that would allow me to retrieve a token from the api that can be used from my .Net MVC client and ajax calls from the browser.
Any ideas, advice would be much appreciated.
thanks in advance. Justin
If you'd rely on Azure AD as your credentials store and authentication system, you'd be able to leverage a ready to use JS library that handles authentication, AJAX calls and session management concerns automatically: see http://www.cloudidentity.com/blog/2014/10/28/adal-javascript-and-angularjs-deep-dive/.
If you can't rely on Azure AD, the code of the library and samples mentioned above can still have value as a reference to build your own system - provided that the authenticaiton system you decide to use offers similar capabilities.
HTH
V.