Azure AD OAuth2.0 Application Permissions - azure

I am trying to setup an API to be protected using Oauth 2.0 in Azure AD. I follow the steps in here: https://learn.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-auth-code-flow.
The API has one scope - one application permission defined. I am able to add the API permission successfully to the client app, and have selected the right scope, as shown in the screenshot.
However, when I test the web app, after authentication the below error is thrown:
The application OAuthClientApp asked for scope approle that doesn
t exist on the resource 2700000003-0000-0000-c000-000000000000.
Contact the app vendor.

App permissions only apply when a client app uses client credentials only for authentication.
So when there is no user involved, app permissions apply.
A client can acquire an access token using their client id + secret/certificate with the scope your-api-client-id/.default or your-api-id-uri/.default.
Documentation for client credentials grant: https://learn.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-client-creds-grant-flow.
.default basically means "the permissions required statically by my app in the registration".
Since app permissions must be required statically, it makes sense to use it.
Authorization code grant, implicit grant and a few others involve a user in the authentication and only delegated permissions apply.
Remember to also grant admin consent for the app permission.
In the screenshot it says consent has not been granted.

Related

Access denied when requesting Oauth2 token from Azure AD with Authorization code flow

We are developing an application with a frontend and a backend. The backend should be accessed via Rest API with an OAuth2 token. Authorization provider is Azure AD.
In Azure we created 2 app registrations. One for the API, one for the client app. The API registration defines 3 scopes (Read, Write, Delete). The client app registration has delegated permission for these scopes.
We are requesting tokens with the clientID and clientSecret from the client app registration.
When requesting a token for a certain scope, after login and approval of permission grant prompt, I just get an access denied error. Does my user need any additional permission in Azure AD to grant permission for the requested scope?
As a workaround I could add the client app as an 'Authorized client application' in the API registration for all three scopes. But then all three scopes are always returned in the JWT under 'scp' regardless of the scope I am requesting and the user does not see the permission grant prompt anymore. Not sure if I want this. I would rather understand how to solve the access denied.
It seems that user consents are not allowed in my organization's AD tenant. (Enterprise Applications -> Consent and Permission -> User Consent Settings.)

Why I am able to access the users of a different tenant without adding any API permission to application in Azure Portal?

I created an application named MyApp in my Tenant A with multitenant access. Also, I didn't add any API permissions to it in Azure Portal. I also removed default User.Read permission.
After that, I implement a backend project with using msal4j library. In backend code, I sent harcoded scope Directory.ReadWrite.All.
After that, I run the backend project. The project showed Microsoft sign in pop up in the browser. I provided the credentials of admin of another tenant named B(Tenant B have 16 users). After the successful sign in, the Permission Requested pop-up showed, It was written a description about the Directory.ReadWrite.All. This was normal since I was add Directory.ReadWrite.All as a scope in my backend code.
After approving that requested permission as an admin of Tenant B. I can list the 16 users of the Tenant B with GET /users endpoint of the Microsoft Graph API. So, the MyApp which was created in Tenant A could access the users of Tenant B.
However, how it was possible? Because I didn't add any API permission to my MyApp in the Azure Portal. You can see above screnshot that is empty. I expected to get an error like "Insufficient privilege" when accessing the GET /users endpoint. But I didn't. I can successfully access the all 16 users although I didn't add the Directory.ReadWrite.All API permission in the Azure Portal into MyApp.
If sending Directory.ReadWrite.All as scope from backend project is enough to access to GET /users endpoint. Why we want to use API permissions in the Azure Portal?
The Azure portal permissions are what we call static permissions.
You use them with the ".default" special scope, e.g. https://graph.microsoft.com/.default.
When you specify a scope in the authentication request, that is a dynamic permission.
It is a feature of the newer v2 endpoint that allows you to request the needed permissions at runtime instead of ahead of time.
It's pretty nice for multi-tenant apps since updating permissions can be done more easily, and you can implement optional features better (that require additional permissions).
Docs: https://learn.microsoft.com/en-us/azure/active-directory/develop/v2-permissions-and-consent and https://learn.microsoft.com/en-us/azure/active-directory/develop/consent-framework

The approval framework is not displayed for users in Azure AD B2C. (User Consent)

i am currently implementing a "System-of-Systems" authentication architecture in Azure Active Directory B2C (AAD B2C). In these scenario there is an initial SSO application that redirects the user to a general dashboard. The dashboard should enable the user to use additional services (service applications). (For example a tile view)
To use these additional services, the user must grant explicit permission for each external service. With this delegated permissions, the user authorizes the service to access certain data (for example, IoT data or personal data).
These AAD B2C application is characterized in this scenario by a client and backend application (api) (for each service). The client application contains scopes (delegated permissions) from the backend application, which are stored as a JWT validation - Policy in each Azure API Management endpoint.
Authentication against these assigned backend scopes already works with the Microsoft Login Provider (Identity Provider), but not with the local Identity Provider (for E-Mail).
Here: My Scenario
I changed the access level from Admin to User in the application manifest: (Here)
Microsoft Access Panel (works here)
My Problem the Local Idenitity Access Panel for users (that doesn't works) -> should look like this: Microsoft Docs (consent dialog)
For the following request:
https://[tenant].b2clogin.com/[tenant].onmicrosoft.com/oauth2/v2.0/authorize?p=B2C_1_SignUpAndSignIn&client_id=xxxxx-xxx-xxxxxx&nonce=defaultNonce&redirect_uri=https%3A%2F%2Fjwt.ms&scope=openid https://[tenant].onmicrosoft.com/backend/Backend.Read&response_type=id_token token&prompt=login
... I always get the following error message:
AADB2C90205: This application does not have sufficient permissions against this web resource to perform the operation.
The approval framework is not displayed for the user, therefore the request is rejected by insufficient permissions.
Do you know how to solve this problem? Are there any walkarounds or configuration options?
Thank u & Best regards
You missed some scopes of your application. Navigate to Applications (Legacy) -> API access, the scope need to add all scopes that you select.
The scopes that you defined are in Published scopes, you could add Full Scope Value in the URL.
This is my URL, and it works well:
https://[tenant].b2clogin.com/[tenant].onmicrosoft.com/oauth2/v2.0/authorize?p=B2C_1_SignupSignin&client_id=xxxx&nonce=defaultNonce&redirect_uri=https://jwt.ms&scope=openid offline_access https://[tenant].onmicrosoft.com/api/demo.write https://[tenant].onmicrosoft.com/api/demo.read https://[tenant].onmicrosoft.com/api/user_impersonation
&response_type=id_token token&prompt=login
For more details, you could see a tutorial and implicit flow.

Is Azure's User.Read permission required for OAuth consent forms?

My multi-tenant Azure application requires only the app-level EWS legacy permission full_access_as_app to run. This app-level permission can only be consented to by an administrator---it's extremely powerful because it gives the app read and write permissions over every EWS mailbox in a tenancy.
If I, as an admin for my Azure tenancy, grant my application only this single permission behind the scenes in AAD configuration, everything works fine when I run the application for my tenancy.
However when you create a new app in Azure, Azure always assumes you will want the user-level Graph API User.Read permission automatically. When you try to remove the permission you get this ominous warning:
And in the case when I leave it out, interactive OAuth consent forms don't work. The error message looks like this.
The client has not listed any permissions for 'AAD Graph' in the requested permissions in the client's application registration. Or, The admin has not consented in the tenant. Or, Check the application identifier in the request to ensure it matches the configured client application identifier. Please contact your admin to fix the configuration or consent on behalf of the tenant.
In other words, it appears that the application won't be able to run for anyone else's tenancy because their admins can't consent to it.
My hypothesis is that this is because Azure is using the User.Read permission to check whether the person signing in through the OAuth form is an administrator. In other words this permission is needed just this one time, before the application is ever run for the admin's tenancy.
Looking at the actual OAuth consent form, this does appear to be the case.The app wants to sign in and read my profile, to check if I am admin... or so it seems to me.
Am I right about this? Documentation I have been able to find is rather scanty.

Azure Delegated and Application permission precedence

I've created a sample web application calling a Web API and using oAuth code grant flow against Azure AD.Application is registered in Azure AD and I have given required permission as well through Azure portal. Everything seems working as expected.
There are two option for permission
Delegate Permission
Application Permission
Is it recommended to use mix kind of permission set (App + delegate) for your application?
If I give similar kind of permission to my API on both Delegate and Application,which permission set will take precedence? Will it depend on oAuth flow e.g. Code grant or Implicit ?
In my code how can I differentiate these permission sets while accessing the same resource.I want to call on user context only even same type of application permission is already there?
Application Permissions and Delegated Permissions are completely independent of one another.
Application Permissions apply when you follow the Client Credential Flow (also known as App Only Flow). When you follow this flow, AAD will try to grant permissions to the client application based on the Application Permissions it has predefined in the app registration. These permissions will appear in an App Only Token in the role claim.
In nearly every other flow, where a user is involved (On-Behalf-Of, Authorization Code Grant Flow, Implicit Grant Flow, etc...) AAD will try to grant permissions to the client based on the Delegated Permissions it has predefined. These permissions will appear in App+User tokens in the scp (scope) claim.
You can control the kinds of permissions your app is granted by adjusting the authentication method when getting an access token to a resource.

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