i have implemented Azure B2C Attentication in Xamarin using Microsoft.Identity.Client nuget package.
after successful login it returning me a Id_Token and if I use this Id token to fetch the web api then the unAuthorid 401 error.Im using this scope
https://{TenatName}.onmicrosoft.com/api/Read.All
You need to create two applications in the Azure AD B2C portal, one representing the client application and the other representing the api application, then use the user to log in to the client application, and use the client application to access the api application.
First, you need to expose the api of the api application:
Next, go to the client application, add the scope exposed by the api application to the client application (you can find your exposed api permissions in My APIs), so that the client can access the api, and then grant the admin consent for the permission.
Finally, I use the ROPC user flow to obtain the token.
Parse the token：
Related
In the past, I have had 2 APIs, both secured with Azure AD. The first API would take the access token and request another access token for the second API with the following param: requested_token_use=on_behalf_of
Info source: https://learn.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-on-behalf-of-flow
However, this is due to both APIs being on Azure AD. Controlled in the same directory.
If the first API was Azure AD and the second was auth0, how would the second API get an access token without the user being able to login to a authorization screen?
In that case you can use Password Grant Flow or Client Credentials Flow.
You can read more about service to service authentication on Microsoft or Google pages.
Does this give you everything you had with on behalf flow? No. With on behalf flow you had token with user's claims for both systems. This way you access service B with service A credentials and if you have fine-grained per user permissions you need to implement logic in service A.
I have a requirement to authenticate ASP.NET Core App via Google Sign In, but a Web API between client app (i.e. ASP.NET Core app) and Google sign in... I know it sounds confusing, so let me explain it with diagrams.
Here is the typical way to include google sign-in button and get user authenticated via their google credentials, It works perfectly fine
Step 1: First, create a new app on google identity developer portal, generate ClientId, ClientSecret and specify redirect_url like : https://yoursite.com/signin-google.
Step 2: In the Startup.cs class of ASP.NET Core project, Use AddGoogle as authentication middleware and it works perfectly fine.
Including diagram below for your understanding:
And here is the proposed flow. With a REST API in between client and google sign in. Question is, how do I authenticate client ?
From what I understand, you want your Client Application to invoke the REST Service on behalf of the user. The REST service needs assurance that both the Client and the User are authenticated.
We have achieved this using the OpenID Connect Hybrid flow. The bad news is that we had to add another service to the solution to achieve this.
How this differs from your proposed solution is this:
You must have your own identity service, and this must know of the existence of the REST service, the Client Application, and the User Identity.
The Client Application redirects the user to authenticate with the Identity Service (which further on redirects the user to authenticate with Google)
Identity Server provides the client application with an ID token for the user, and also a code which can be exchange for an Access Token
The client application requests the Access Token. This Access Token will authenticate both the client and the user
The client application then authenticates using this access token when invoking the REST Service
The REST Service issues a one-off request to Identity Server for the signature keys, and uses these keys to validate the access token.
We happened to use IdentityServer4 when implementing the Identity Server, but the protocol exists independently of any one implementation.
I'm trying to setup an application to validate identity using Azure AD and acquire a token to allow access to a secure api. The front end application is written in angular and allows anonymous access. What can I use to access AAD authenticate and return an access token?
This will be an angular 6+ UI that is communicating to a secure .Net api using Azure AD for authentication. I have done a couple days research and everything points to a user logging in to authenticate using the login page. I need it to be by app and open the login page. I tried a couple examples where it utilized authentication/authorization and that didn't work because the app needs to authorization the user to talk to the api. I have seen where people were using Microsoft graph but once again it was user based and they were redirected to an azure login. I am looking for a solution that will allow me to setup an account in azure ad and authenticate the app on start to get an access token to allow communication to my secure api. If I have missed something somewhere in my research and test attempts let me know. This is my first Azure AD auth attempt and I feel like I am missing something for application authorization.
The problem is an Angular app is what we call a public client.
It cannot hold secrets and thus cannot prove its identity.
So, only user-based authentication flows should be used by public clients.
Confidential clients on the other hand can hold secrets as they run on servers that you control.
So for example, a back-end Web application or API would be a confidential client.
Those can use the client credentials flow to acquire access tokens and call APIs as themselves without a user being involved.
There is a bit of a fundamental issue in your question.
Your API requires authentication, but you want functionality to be available to anonymous users.
So you want to bypass authentication.
If you really want to bypass authentication for parts of the API, you could just make those endpoints available anonymously without a token.
I have a web app front end and web api back end both written in ASP .Net Core 1.1 MVC. I am using Auth0 as the authentication server, using the "authorization code grant flow".
So the user logs in - i.e. the user gets directed to Auth0's login screen, which, if the username and password were correct, sends the web app back an authorization code, which the web app then exchanges for an access token, which is then used for all web api calls.
Then, the user clicks on a link which makes the web app call upon a web api action. My question is, how can the web api know which user is making the request? Or maybe at the point the user successfully logs in, the web app should call upon a controller in the web api and tell it which user just logged in? Not sure what the best practice is...
Thank you
I will answer in terms of OAuth 2.0 specification.
Specification determines 4 roles:
Resource owner
Resource server
Client
Authorization Server
In your context:
Resource owner is end-user.
Resource server is your Web API.
Client is your web application.
Authorization Server is Auth0.
Follow steps:
Your Web API should be registered on Authorization Server
(https://auth0.com/docs/apis).
Your Web API should be responsible to validate access tokens that
are used for requesting API. This access tokens contains info about
end-user/client (https://auth0.com/docs/api-auth/tutorials/verify-access-token).
You should include Web API scope in authorization request.
You should get access token in your web application and include it in HTTP request to Web API.
I've created a mvc web application that uses openid to authenticate with Azure Ad and get the claims along with the token. I'm interfacing with Web Api to do the business transactions. The web Api is configured to oauth bearer tokens.
I've created separate oauth clients in Azure Ad for the Web App and Web Api. I'm able to get a token for Web Api from the Mvc Controller using AuthenticationContext to send to request to Web Api. I need to know how I can send the current User Claims as well to the Web Api. The claims in the Web Api are not having the claims of the User from the Web App.
Let me provide a bit more context here. I've created a MVC Web Application and a Web Api layer. The MVC Web App is configured to use OpenID authentication using Azure AD and I've configured the Web Api layer to authorize using OAuth Bearer tokens. The actions in the Web Api layer will be called through ajax requests and the bearer token will be added to the header of each Ajax requests. When the User is authenticated in the Web App, additional claims are added to the User on top of the claims from Azure Ad. I'm able to create a token for the Web Api layer using AuthenticationContext.AcquireToken, but the token for Web Api does not have the User info from the Web App.
I'm taking a wild stab in the dark here, based on what I think is happening.
Claims are attached the user, so theoretically, any claim you add in one place should be available in the other, as long as both applications share the same user datastore. However, claims are loaded at the point of authentication and not dynamically updated. As a result, if you're already logged in to the web application and you add a claim with your Web Api, that claim will not be available on the web application side until the user is re-authenticated.