Practical issues about Azure OAuth 2.0-protected api - azure

We are providing a web api that is protected with Azure OAuth 2.0.
Our affilates will use this api and they each will get a clientid/client.
1) In the linked scenario. Why would there be need for a refresh-token?
if the token expires their (web)application would just send for a new token using their clientid and sclient secret?
2)
We have 100+ affiliates. Almost all of them will have same permissons, but we still want to give everyone a unique clientid/secret. How do we practically do this? Is manually in azure web portal the only way?
Azure Oauth - how to change token expiration time?

1) In the linked scenario. Why would there be need for a refresh-token? if the token expires their (web)application would just send for a new token using their clientid and sclient secret?
Refresh tokens are used if the client makes a delegated call to your API.
In this case the token will contain the currently logged in user's info as well.
The client can use the refresh token to get a new access token for your API for a specific user when the access token expires (instead of redirecting them to login again to get an authorization code etc.)
If they call your API purely using client credentials (id + secret) then there will not be a refresh token.
2) We have 100+ affiliates. Almost all of them will have same permissons, but we still want to give everyone a unique clientid/secret. How do we practically do this? Is manually in azure web portal the only way?
To get a unique client id for each affiliate, you must create a new app registration for each of them.
You can automate this process by creating the Application and Service Principal via one of the Graph APIs (Azure AD Graph or MS Graph):
AAD Graph: https://msdn.microsoft.com/Library/Azure/Ad/Graph/api/entity-and-complex-type-reference#application-entity
MS Graph: https://developer.microsoft.com/en-us/graph/docs/api-reference/beta/api/application_post_applications
Note the MS Graph endpoints for applications are still in beta and not recommended for production use.
This is one of the very few cases where Azure AD Graph API is the supported case.
You will need to create an Application for each affiliate (remember to create the passwordCredential (secret) as well),
then create a Service Principal based on the Application,
and then grant the Service Principal rights to your API.
If these are application permissions, you will have to create appRoleAssignments.

Related

Azure AD auth + Angular/MSAL + ASP .NET Core best practices of tokens revocation

We are working on a web application. At client side we have Angular application that has integrated MSAL library for Azure AD authentication. At backend we have Asp .Net Core application that integrates MSFT Graph API service and sends http requests to Graph API on behalf of authenticated user. Main purpose for this Graph API requests is to manage App Roles assignments. So, our client side has UI for App Roles assignments management. Access token we receive from Azure AD contains set of assigned App Roles. Client side UI rendered according this set of App Roles (some menu items are hidden for low privileged roles).
Current task is invalidate/revoke client side token once user's App roles set updated.
Implemented steps: token lifetime decreased to 10 mins (minimal of allowed values).
Right now we are trying to use RevokeSignInSessions method of Graph API. It seems to be working for Azure Portal but does not for our client side. Seems that portal has some special settings for handling tokens.
Question: Is there any recommended way to go with such requirements?
If you use Azure AD for authentication, you should get an access token and a refresh token.
If you wish to revoke the refresh token, you can use power shell: Revoke-AzureADUserAllRefreshToken, or AAD Graph API : POST https://graph.windows.net/{tenant id}/me/invalidateAllRefreshTokens?api-version=1.6 HTTP/1.1.
However, the access token cannot be revoked, and it will automatically expire after 1 hour.

Azure ADB2C access without a user

I am using an Azure ADB2C tenant to sign-up/in users with custom policies and rest api claims exchanges. This works fine.
Now I would like to start a service (daemon) that runs in a cloud environment for each user that signs-up with my service. This background service will access resources on other servers. Accessing these resources require a token and the service should only have access to the resources that the user has (i.e.: the access token used by the background service should also include the custom REST API claims). For the common users, this is taken care of by my REST API claims server, which enriches the token in such a way that it gives users' access only to the allowed resources.
I have found this page describing how to get access without a user. But this page assumes that the background service is a single instance that has access to all users' data that it needs. My background service is a 1-to-1 mapping to the signed up user.
Ideally this is how I see it working:
A new user signs up.
My REST API claims exchange gets called for this user.
Call Azure ADB2C to create a token for the background service. (Token should also contain my custom claims)
Start a new instance of the background service using the token created at step 3.
Return the custom claims for the new user.
This will happen for every new user, so every user in my system will have a corresponding background service running in the cloud.
Is this possible with Azure ADB2C? If yes, how?
The link you provide to get access without a user is only suitable for calling ms graph api and not for calling custom api.
If you are calling ms graph api, then you can indeed use the daemon-based client credential flow to obtain an access token (that is, without user involvement). This flow is usually used in Azure AD, but if it is used to call ms graph api, then it is also applicable to Azure AD B2C.
But if you are calling a custom api, then you must use a user login flow. Azure AD B2C obtains tokens in a different way from Azure AD. To use Azure AD B2C, you must first create a policy to enable users to sign up and sign in to your application.

Credentials prompt for access to Azure management APIs

I've been using the Azure fluent management APIs (https://github.com/Azure/azure-libraries-for-net) with some success in .NET Core.
However, I want to prompt the user to enter some credentials for a Microsoft account. Those credentials would have access to one or more Azure tenants / subscriptions, so I'd like to be able to use the result to browse and manage resources there.
This is something very close to what I would believe Azure Data Studio does: you can enter some Azure creds, and your resources will appear in the app.
I'm trying to understand the best approach for this. There seem to be a billion sites out there when you talk about Azure AD app registrations, but I haven't found a fruitful specific search query yet. I know I can register an app, get a client ID and client secret. I know I can set it to be usable by organisational accounts in the current tenant, or all tenants.
I can add the "Azure Service Management (delegated permissions : user_impersonation)" permission to my API permissions section for the app, but what's next?
If I use Microsoft.Identity.Client (as in https://learn.microsoft.com/en-us/azure/active-directory/develop/quickstart-v2-netcore-daemon), I run into some questions:
AcquireTokenForClientAsync doesn't prompt the user - I guess because it's getting a token for the app to act with its own permissions?
AcquireTokenOnBehalfOfAsync wants a JWT.. great! I'll pass the one I got from AcquireTokenForClientAsync! Nope, AADSTS70002: Error validating credentials. AADSTS500137: The token issuer doesn't match the api version: A version 1 token cannot be used with the v2 endpoint.
I don't know what scope I want. https://management.azure.com/user_impersonation is apparently invalid.. https://management.azure.com/.default works, but is that right? It's a guess, combo of the former and a .default suffix I found for Graph API scopes online. Any docs on this?
I ultimately get a JWT and tenant ID back. I can't find a way to use a JWT with the Fluent management APIs.. and my account (for instance) is associated with 3 tenants or 5 different tenants / directories - so how do I choose?
That's just what I've tried, the appropriate route might be a different one. In summary: I want a .NET Core Console app to request user credentials, and then get access to the Azure resources they have access to, in order to perform some resource management.
AcquireTokenForClientAsync doesn't prompt the user - I guess because it's getting a token for the app to act with its own permissions?
You are using the OAuth 2.0 client credentials grant to access web-hosted resources by using the identity of an application. This type of grant commonly is used for server-to-server interactions that must run in the background, without immediate interaction with a user .
AADSTS70002: Error validating credentials. AADSTS500137: The token issuer doesn't match the api version: A version 1 token cannot be used with the v2 endpoint.
Azure AD provide two service : Azure AD V1.0 and Azure AD V2.0 . Please refer to Comparing the Azure AD v2.0 endpoint with the v1.0 endpoint . You can't use v1 token to acquire v2's token in a on-behalf-of flow .
AcquireTokenOnBehalfOfAsync wants a JWT.. great! I'll pass the one I got from AcquireTokenForClientAsync
AS pointed above , That function is used to acquire an access token for this application (usually a Web API) from the authority configured in the application, in order to access another downstream protected Web API on behalf of a user using the OAuth 2.0 On-Behalf-Of flow. So you can't use app token which acquire using Client Credential flow .
https://management.azure.com/.default works, but is that right? It's a guess, combo of the former and a .default suffix I found for Graph API scopes online. Any docs on this?
You are using the Azure Active Directory v2.0 and the OAuth 2.0 client credentials flow , when sending a POST request to the /token v2.0 endpoint ,the scope should be :
The value passed for the scope parameter in this request should be the resource identifier (Application ID URI) of the resource you want, affixed with the .default suffix. For the Microsoft Graph example, the value is https://graph.microsoft.com/.default. This value informs the v2.0 endpoint that of all the direct application permissions you have configured for your app, it should issue a token for the ones associated with the resource you want to use.
Please check the Get a tokensection in above document .
I ultimately get a JWT and tenant ID back. I can't find a way to use a JWT with the Fluent management APIs..
AFAIK , currently Azure AD V2.0 apps can use:
Its own API
Microsoft Outlook APIs
Microsoft Graph API
Azure AD V2.0 currently doesn't support Azure management APIs .
So you problem is you need to allows work and school accounts from Azure AD and personal Microsoft accounts (MSA) which works with Azure AD V2.0 , but you can't use Azure management APIs . You can use Azure management APIs in Azure AD V1.0 but it allows only work and school accounts to sign in to your application , unless you invite Microsoft accounts as guest user in Azure AD V1.0 ,but you need to configure to point to the tenant-specific endpoint :https://login.microsoftonline.com/{TenantId_or_Name}). during authentication if you want to login with MSA in v1.0 apps.
Update:
You can use Code flow and azure ad v1.0 endpoint , user will be redirect to AAD's login page and enter their credential. Here is code sample for .net Core .
With Azure AD V1.0 endpoint , requests are sent to an endpoint that multiplexes across all Azure AD tenants: https://login.microsoftonline.com/common . When Azure AD receives a request on the /common endpoint, it signs the user in and, as a consequence, discovers which tenant the user is from. See document here . But in this scenerio ,you can only use work and school accounts(AAD) account to login .
The code sample in your link is using Azure Service Principal for Authentication , no interactive user login . You can use OpenID Connect Owin Middleware for authentication in .net Core applications as shown here .

Azure API Management Client Authentication

I have an API Management resource on Azure which uses an API running as a Kubernetes cluster.
I want to have OAuth2.0 authentication for clients/applications which connect to the API management URL. I do not want any user authentication, but only want clients which want to use the URL to send a client ID and client Secret.
How do I do this?
I could not find anything related to this in the documentation.
If you dont want user context to be involved, You must prepare client credential flow from Oauth2.0 which uses client id and client secret.
I am explaining using Azure AD.
1) Create Application in Azure AD and get client id and secret
(https://www.netiq.com/communities/cool-solutions/creating-application-client-id-client-secret-microsoft-azure-new-portal/)
2) Call token end point of Azure AD to get secured token
(https://learn.microsoft.com/en-us/azure/active-directory/develop/active-directory-protocols-oauth-service-to-service)
3) Pass this token to APIM using authorize or from any header
4) Validate JWT and check issuer,audience and application level scopes
(https://learn.microsoft.com/en-us/azure/api-management/api-management-access-restriction-policies#ValidateJWT)
No sure what exactly are you asking!
But here are two places where you will find a solution to your question:
How to secure your backend apis: https://learn.microsoft.com/en-us/azure/api-management/api-management-howto-protect-backend-with-aad
API Management access restriction policies: https://learn.microsoft.com/en-us/azure/api-management/api-management-access-restriction-policies. More specific here check the Validate JWT (https://learn.microsoft.com/en-us/azure/api-management/api-management-access-restriction-policies#ValidateJWT)

Getting access token in azure with azure account username and password

I am trying to gather metrics info of azure resources. For that i need an access token to authorize. But to get an access token i have to give client id, client secret, subscription id, tenant id.I was wondering if i could get this access token without giving so many details except username and password of my azure account.
Basically you need the parameters. Azure's APIs are protected by Azure AD so you have to authenticate against it first. If you want to make calls as the user, you still need to authenticate with one of the few ways available. The password grant (as shown in #4c74356b41 answer) is one option, though it is not really recommended. The reason is that if the user's password has expired or has MFA enabled, it won't work.
What you usually do is request the user to login via Azure AD sign-in page (via redirect or web view), and then exchange the resulting authorization code for an access token and refresh token. Then you can make calls against the APIs as the user.
Another option is to register your app in Azure AD and grant its service principal some roles in your Azure subscriptions/resource groups/resources. Then it can authenticate with client credentials (using only its client id and secret + your Azure AD tenant id).
it is possible, but it is considered not safe. And you would still need a lot of parameters:
Name Description
grant_type The OAuth 2 grant type: password
resource The app to consume the token, such as Microsoft Graph, Azure AD Graph or your own Restful service
client_id The Client Id of a registered application in Azure AD
username The user account in Azure AD
password The password of the user account
scope optional, such as openid to get Id Token
Reference:
https://blogs.msdn.microsoft.com/wushuai/2016/09/25/resource-owner-password-credentials-grant-in-azure-ad-oauth/
ps. Don't mind Walter, he is wrong like 50% of the time in his answers.
It really depends on your need and if you want this fully automated or not.
If you want to have a token for a ServicePrincipal, the answer of 4c74356b41 is a great way to do it.
However if you would want to obtain a bearer token for a user (you or another AAD user) that is already authenticated in a PowerShell session, you could do this very easily if you use this piece of code that I wrote.
https://gallery.technet.microsoft.com/scriptcenter/Easily-obtain-AccessToken-3ba6e593
Basically what it does, it fetch the current token from the token cache and return it to you. This way you don't have to deal with clientId, cliendSecret or certificate. I use this all the time when I need to call the Azure REST API on a Just In Time fashion.

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