I'm using azure Active Directory, Client Credential Flow in my organization's Web API access control.
I have the below applications registered in the AD:
backend-app
client1
client2
Now, even if I do not give delegated access in Client1 to backend-api, client 1 is able to acquire a token for the resource "backend-app". Is there anyway I can avoid this from happening? I do not want clients that I've not explicitly given delegated access to be able to acquire the token.
This flow works fine in Native apps, where AAD throws an error indicating the client1 doesn't have required permissions for backend-app.
Under Enterprise applications - Application Name - Properties, there's a setting User assignment required? Setting this will only allow explicitly assigned users to access an application.
Taken from the infobox on the Azure Portal:
If this option is set to yes, then users must first be assigned to this application before being able to access it.
More info on Assign users and groups to an application in Azure Active Directory
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We are designing a web application and want to use Azure AD External Identities.
We define Multiple clients in our web application, and each client can have multiple users. A client invites users and gives them access to data by their email addresses, which could be personal or organizational.
Users log in to the application. After the login, if they have access to multiple clients (because different clients can invite them), they should be able to switch between clients and get an access token for the selected client.
It is essential to mention that each user has different permission on different clients; for example, a user can have admin permissions in one client and simple user permissions in another.
Is it possible to have these features in Azure AD?
How should We use Group, Scope, and Role to implement it?
Whenever external identity providers (azure ad in this case) are used in 3rd party application:
It's scope which defines permissions. It can be specified at client(application) level. Hence Whatever scope you define for a particular client it would apply to all users. Obviously You can create multiple applications which contains different scope.
roles,groups has nothing to do with generating access tokens since those are used only when you login into azure portal.
Here You will have to use client credentials flow of OAuth 2.0. Otherwise user will need to login each time if auth code flow is used.
I've been poking around MS Graph OAuth2 consent and access token for the enterprise Azure app that had been created along the way. Basically, I'm confused why when I delete the app, I'm still able to obtain the access token ?
When I decrypt and check the claims, it is referencing the name and object id of the deleted app, but it has no roles, and can't be used to access any resources, which makes sense. But still, I'm confused why is being issued for the app that doesn't exist any more ? For example, if I open the app and select to disable login for users, access token is no longer issued - but deleting the whole app does not behave in the same way.
While working with applications in Azure AD, you should be aware of few things like:
App Registrations is where you register an application and configure the details like API permissions, client secrets, client certificates, token claims, app roles etc....
Enterprise Applications are list of service principals that are associated with applications in App Registrations which defines who and what resources the application can access.
When an app is registered in Azure AD, it's corresponding service principal will be created with same name and same App ID in Enterprise Applications blade automatically.
Please note that, whatever changes you do to service principal will directly affect the registered application and vice versa.
I tried to reproduce the same in my environment and got the below results:
I have registered an application in Azure AD and granted permissions like this:
Go to Azure Active Directory -> App Registrations -> Your App -> API Permissions
I generated an access token using client credentials flow, and I can see the roles claim in decoded token like below:
Now, I deleted the Enterprise Application of same name and App ID like below:
Go to Azure Active Directory -> Enterprise Applications -> Your Application -> Properties -> Delete
After deleting that Enterprise App, I'm still able to generate the access token and can't find roles claim now like below:
As the service principal of the application is deleted, you cannot access the other resources which removes permissions from token.
Please note that,
If you delete the application in App Registration first instead of Enterprise App, it will automatically delete the associated service principal (Enterprise App) too along with it.
Then you cannot even generate the access token as it gives Unauthorized client - Application not found error. Unable to generate access tokens is similar to disabling login for users.
Reference:
Apps & service principals in Azure AD | Microsoft Docs
I am trying to find security best practice on App permissions in the context of azure resource management.
Currently, there is only one permission listed for management.azure.com and it is
management.azure.com/user_impersonation (preview). This delegated user impersonation can be a serious problem and it can led to account takeover by malicious app.
Think about a scenario where a user with global administrator role consent and authorize an access token to the app. App can use the token and do whatever it wants with the azure tenant.
Another scenario where a privileged user assigned contributor role to multiple subscriptions. Token authorized by this user can be misused by app to modify resources in any of the subscriptions.
Unlike graph (graph.microsoft.com) api where you can handpick the permission (user.read), resource management api has only one option - user_impersonation!
You may argue why would a privileged user authorize the action but people make mistakes. Our job is to stop or minimize such risk by design. So, what's the best way to allow app to manage resources in azure and minimize the security risk?
Thanks to #juunas for outline and tips. Thanks to #Gaurav for attempting to address my question. I was able to modify azure resources on a subscription without having to grant user_impersonation on management.azure.com api. Here are the steps-
1) Register an app (TestPermissions in my case)
2) Add API Permissions (optional). You don't need to add management.azure.com.
3) Go the Azure resource (subscription, resource group or management group level based on your requirement) and add IAM/RBAC role to the registered app. I assigned Contributor role to TestPermissions app at the subscription level.
4) Request a oauth2 access token following client credential grant flow. You can provide client_id and client_secret in the body of the POST request or you can provide it as Authorization Basic base64 encoded header (that's what I did). Save the access token for future use (until it expires).
Note: I could not add multiple audience (scope) at the same time. If you would like to get a token for graph api, you can request a separate token by changing the scope to http://graph.microsoft.com/.default
5) Use the access token captured in the previous step to interact with azure resource manager. You will need to add the jwt bearer token in the Authorization header (not shown here) on every request to https://management.azure.com. In this example, I am creating a new resource group named TestCreateRG003 to one of my Pay-as-you-go subscription.
6) Let's validate/verify that the resource is created or updated in Azure. Bingo, there they are! App can read/modify (based on RBAC) azure resources w/o having to grant impersonation permission.
It is true that by granting that permission you are allowing the app to act as you, with all the permissions that brings.
The main way I've seen used when limitations are desired is that you:
Register an app in your Azure AD
Grant the service principal the necessary roles (e.g. Reader on specific resources)
Set the tenant id, client id, client secret etc. in the app
This of course requires that the app itself supports this approach.
If it only allows usage through impersonation, then you'll need to either trust or not use it.
Let me see if I can answer this question.
When a user requests a token for management.azure.com, all is done at that time is that the user has permission to execute Azure ARM API. That doesn't mean that they can do everything that's possible with Azure ARM API.
The things that they can do is controlled by Azure Role Based Access Control (RBAC). So if a user is in the Reader role, the token got on behalf of the user can only read information about resources in their Azure Subscription. They will not be allowed to create, update or delete resources in their Azure Subscription.
What you will need to do is grant users appropriate RBAC role to minimize the risks of misuse.
I have a client application which runs as daemon mode [no interfaces].
This daemon will speak to app created in Azure (single-tenant currently) to fetch users using O365 Graph API.
Authentication mechanism used is Auth2 certificate/thumbprint.
Permission to app is given directly by admin while creating app in azure itself.
Now i need to make this daemon (client) and app in azure as multi tenant.
Things i followed after reading some articles
Mark app as multi-tenant in azure
Point to /common in token url in client (which runs as daemon) https://login.microsoftonline.com/common/oauth2/token.
Questions:
After this i was able to get access token , but for any query i make i am getting error "The identity of the calling application could not be established".
Since there is no user intervention here , how do i give permission for tenant B app to access tenant A's data like users in my case ? Anything i can do in manifest file
If tenant B's app is accessing tenant's A data , should both app in azure be mutlitenant ?
Lot of articles explains how is the flow based on user login (user consent). But my client application runs as daemon. How do i give permission directly/mechanism in azure app for accessing other tenant's data ?
[Assume i am admin of both tenants and i have complete access to both tenant]
It isn't possible to use the common endpoint when using the client_credentials flow to log into the \OAuth2\token endpoint. This is because common is designed to identify the user's "home" directory and when they log in interactively they are redirected to sign into their home directory unless overwritten.
2 & 3. Tenant B doesn't get a registered application it only get an Enterprise Application. The linked Registered App would be the one is Tenant A, communication here isn't bi-directional. A has an Enterprise Application in A and an Enterprise Application in B. You set the permissions for all the Enterprise Applications using the Registered Application in A but an Admin/User -dependant on the permission type- will have to grant permissions in their respective tenant (A & B). When you log in as a user you utilise the Application Registration. In order to access B you will have to call the token endpoint containing B's tenant id.
To enable one application to be able to access multiple tenants you need to:
make the Application Multi-Tenanted. Make a note of the application's ApplicationId.
Using PowerShell log into the tenant you want to give the Application access to.
Use the Cmdlet New-AzureRmServicePrincipal -ApplicationId <ApplicationId> where is the one you noted earlier.
This will create a service principal in tenant B based on the application in Tenant A. The application in A when then be able to use the token endpoint for Tenant B to log in an access.
We are building a Web App/API to publish in our Azure AD and want to provide access to the app by inviting (B2B scenario) external users into our Azure AD. This will create accounts in our Azure AD of type "Guest" which we will use to assign permissions to the app. In this scenario, do we need to configure our application to be "multi-tenant"? There are steps to take inside the code to accommodate for multi-tenant sign-ins and there is a setting on the Settings tab of the App Registration in Azure AD that is labeled "Multi-tenanted" where you select either Yes or No. On the App Registration setting, there is a pop-out bubble that says:
Designates whether users in external organizations are allowed to grant your
app access to data in their organization's directory
I am not sure how (or if) the code changes and the app registration setting are related but our app will not need access to any data outside of our directory.
No your app does not need to be multi-tenanted and you do not need to direct users to the /common endpoint. I have tested this, and you still get a kind of SSO experience.
Example paul#org1.com (homed in Org1 AAD) is a guest user in Org2 AAD (invite has been accepted). Now this same user opens a private browser and logs in to Org1 AAD.
The user then tries to hit a web app with app registration in Org2, and web app redirects user to https://login.microsoftonline.com/org2.onmicrosoft.com/oauth2/authorize.
Result, user is considered logged in by AAD and gets redirected to the redirect_url with tokens, etc.