Authenticate Azure AD v1 WebAPI from Azure AD v2 mobile app - xamarin

We have a Xamarin forms mobile app where users are authenticated by AAD v2 endpoint (MSAL - Microsoft.Identity.Client) and an ASP.NET Web API application where the same users are authenticated by AAD v1 endpoint (ADAL - Microsoft.IdentityModel.Clients.ActiveDirectory).
We would like to have REST calls authenticated in the Web API from the mobile app. We've tried passing v2 authentication tokens but get InvalidAuthenticationToken returned to us.
First of all not sure if it is actually possible. This MS presentation from 2017 says that it hasn't been implemented 'yet', but can't find whether it is now possible. Failing that, is there some other way to get this to work?
Thanks

Background
This should be possible. With recent change, there is no longer a difference of v1 or v2 client app, rather the targeted "audiences" (e.g my tenant only, all tenants, Azure AD + MSA) of the APIs they're requesting access to.
Quick example
Setting that aside, there is still a notion of token version. The version of the token, however, is that of the API, not the client app. For example,
Client A: targets Azure AD only (formally would map to a v1 app)
Client B: targets Azure AD + MSA (formally would map to a v2 app)
API: accepts Azure AD + MSA (formally would map to a v2 app)
In this case, the access tokens issues to Client A and Client B will be a format understood by the API- v2.0 tokens.
Conclusion
In your case, you can register each client based on the type of users you want to allow access, but ultimately your API will represent the token type issued.

Related

Can we use both ADFS and Azure AD token in the same Spring boot project?

I am working in a project where we are authenticating any REST API requests from UI or anywhere else using ADFS STS tokens. There are some direct calls from UI with ADFS STS token in header for authentication/authorization and there are some external 3rd party calls not from UI, but also using ADFS STS tokens in header. Now we are planning to migrate partially to Azure AD token, post which there may still be some applications that will keep using ADFS STS tokens, so there can be situation where an external application that is unaware of migration to Azure may still call an internal application using ADFS STS Token and we are supposed to be compatible with it. Similarly there can be a situation that an internal application that is migrated to Azure AD token is internally calling one of the legacy applications which is still not migrated to Azure AD and won't in future too.
I have two challenges now:
How to support the above design so that even if an Azure token is used the API is still able to call an external service (working on ADFS) by creating an ADFS token from within the code and setting it in headers ?
Header in a HTTP request seems to be an unmodifiable data and when i tried to modify it within a requesttemplate in an request interceptor code, it failed saying unmodifiable map.
How do I handle this ? Please someone help.
Unfortunately I cannot share code due to internal restrictions.
Please check if below references provide some idea in your case.
According to Mix ADFS and Azure AD for authentication - Microsoft Q&A.
If you have O365 federated with ADFS and you federate an application
with Azure AD, the authentication flow would be:
User accesses the application which is federated to Azure AD.
Application will redirect to Azure AD authentication endpoint (https://login.microsoftonline.com) for authentication.
User will be prompted for credentials.
Based on the UPN suffix (If the domain is federated with ADFS), user will be redirected to ADFS.
ADFS will authenticate the user and issue a WS-Fed token to Azure AD.
Azure AD will receive the token and issue a SAML token to the application.
User will finally get access to application.
References:
Configure AD FS 2016 and Azure MFA | Microsoft Docs
Azure AD Connect - Manage AD FS trust with Azure AD using Azure AD
Connect | Microsoft Docs
federating ADFS with Azure Active Directory (techdirectarchive.com) & reference- Solution Zone

Using two azure AD app registrations for mobile and web

I have a mobile app which gets token directly from azure login. And I have a service which is using adal4j in spring boot. I cannot use the mobile generated token to authenticate spring service. Becase I use two different azure app registrations for mobile and web service. Is there a way to accomplish this ?
My understanding is that you have created 2 Enterprise Applications in Azure.
1) An Enterprise Application for your mobile app (Type: Native)
2) An Enterprise Application for your Web API app (Type: WebAPI)
For native app, you will not need a client secret but you will need a client secret for the Web API app.
Now coming to the key configurations:
In both of these, please update the manifest file to have oauth2AllowImplicitFlow set to true
Also, in your Web API Enterprise Application, please have the app id of your native app in the known client apps
"knownClientApplications": ["
Now, when calling your Web API through an end-point from the Native application, pass your token in your request header as "Authorization": "Bearer "
Also note: if you need to retrieve group claims, please update the manifest in both your enterprise apps to have the following setting for this property
"groupMembershipClaims": "SecurityGroup"
Update:
Under permissions in the native app, please add the Web API app registration to allow access
Yes, the OAuth 2.0 on-behalf-of flow should applies to your scenario. These steps constitute the On-Behalf-Of flow.
Azure AD issues a token for certain resource (which is mapped to an Azure AD app). When we call AcquireToken(), we need to provide a resourceID, only ONE resourceID. The result would have a token that can only be used for the supplied resource (id). There are ways where you could use the same token , but it is not recommended as it complicates operations logging, authentication process tracing, etc. Therefore it is better to look at the other options provided by Azure and the ADAL library. The ADAL library supports acquiring multiple access-Tokens for multiple resources using a refresh token. This means once a user is authenticated, the ADAL’s authentication context, would be able to generate an access-token to multiple resources without authenticating the user again.
Further details here.

Azure AD exchange access_token with id_token v.1.0 endpoint

I will draw a scenario, and need some suggestions:
I'm using Azure AD (v1.0 endpoint), a single-page app (SPA) and a web API. The SPA establishes the user's identity using OpenID Connect, authenticates the user and receives an id_token and access_token for the back-end web API.
Now, we don't want the SPA to do access control decision based on the id_token received within the SPA app.
Instead, the SPA sends the access_token to the back-end web API to access it, and now we want back-end web API to make an access control decision based on the roles claim found in the id_token, but which the back-end does not receive from the SPA.
The question is, is it possible for the back-end web API to send received access_token to Azure AD token endpoint and receive the relevant id_token for the user so that the back-end web API receives an id_token containing the roles claims for the user, in order to make an access control decision?
There are a couple issues with the approach as you describe it:
The app roles would be defined on the native client application (the SPA). Though you can technically define app roles in the manifest, you'll notice the Azure portal won't let you assign users or groups to a native client app. (Which sort of makes sense, because, as you've rightly said, you don't want to do any access control in the native client app.)
You can't do what you've described (exchange an access_token intended for one audience, for an id_token intended for a different audience). There are some variants of token exchange which you can do, but none of them would help you in this situation.
Instead, what you should do is define the app roles on the web API. Then, assign the users to the corresponding app role for the web API. When these users sign in to the SPA, and the SPA gets an access token on their behalf to the web API, you'll notice the access token will contain the roles claim, populated with the appropriate values.
Summarizing:
Under App registrations for the web API, define your appRoles in the app manifest (or on the Application object directly, using (for example) Azure AD PowerShell).
Under Enterprise apps for the web API, assign users and/or groups to their corresponding app roles, and choose whether or not app role assignment is required or not*. (Or do so directly on the ServicePrincipal object.)
Under App registrations for the SPA (the Application object), add the web API as a required permission.
*If you choose to require app role assignment for the web API (under Enterprise apps > Properties), the SPA will not be able to get an access token for users who are not assigned to an app role for the web API. If you choose not to require app role assignment , users who are not assigned an app role will be able to sign in to SPA and the SPA will be able to get an access token on their behalf for the web API, but the access token will not contain a roles claim.

Identity Server as part of Web API or separate app

I have an ASP.NET Core Web API app and to secure it, I've implemented JWT Bearer authentication. The next step is managing user access and issuingJWT token.
Initially I considered using Azure AD B2C but it doesn't seem to support my business requirements. So I'm now considering using Identity Server 4.
Is Identity Server 4 run as a completely separate application? Also, am I understanding it correctly that it is used as:
A web interface for users to register and login
Also a web app with API that issues the JWT token
In other words, does Identity Server 4 "act" as my own Azure AD B2C service?
IdentityServer 4 is a Web app (Login & Logout pages) with an API that implements the OAuth 2.0 and OpenID Connect specifications. The samples provide a simple user login and logout views that you can change to your liking.
Regarding the user registration process, you may add that to your IdentityServer4 implementation or have that as a separate web application.
Similarities to Azure AD B2C
This came from another blog article
Authorization
Azure AD B2C allows you to model user roles as membership in groups
that you define. You can’t currently get a token containing those
claims, but you can use the Azure AD Graph API as a workaround to
retrieve the group memberships, and use them in authorization checks
inside your application. It’s a little tricky right now, but
improvements to this are on the B2C team’s roadmap.
API Authentication
Azure AD B2C can provide tokens for authenticating API access via
OpenID Connect, but beyond that the functionality is limited. The
OAuth 2.0 Client Credentials flow isn’t supported, and B2C doesn’t
include any API key management features, so you’ll need to roll your
own code if your services need to support API key authentication.
Another article with PROS for IdentityServer4.
IdentityServer 4 is an authentication framework capable of out of the
box Single Sign On (SSO) and security for your APIs, and most recently
support for implementing your own authentication protocols and tokens,
with a sample implementation for the WS-Federation protocol and SAML
tokens. SSO works across all applications regardless of whether they
are using OpenID Connect or WS-Federation.
Summary
IdentityServer4 is similar to Azure AD B2C with more functionality as noted in the linked articles.

ADFS 2016 - ApplicationGroup - single native app - multiple web api endpoints

I'd like to validate the following scenario:
ADFS (win2016) is acting as an Identity Provider in a setup where
a single mobile app is consuming 2 api's
api.contoso.be
otherresource.contoso.be
These three applications are grouped together in a ADFS Application Group:
mobile app as a "Native application"
api.contoso.be and otherresource.contoso.be as "Web API" applications
The mobile app gets an access token when authenticating succesfully against ADFS.
The access token is provided with een aud-claim for "api.contoso.be".
Problem: I'm currently unable to reuse that same access token to access the second api "otherresource.contoso.be".
Question: at this point I'm not 100% sure that ADFS ApplicationGroups are meant to support such a scenario.
If so, I'm probably overlooking something in the ADFS-configuration.
If not, what's a better ADFS setup to support this scenario?

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