Can't deploy an app to Intune store via graph API - DeviceManagementApps.ReadWrite.All is an invalid scope? - microsoft-graph-api

Question

We want to enable uploading apps to the Intune store via an API.
I saw this example on GitHub, and want to do something similar in JS, so I've tried using the same REST calls.
The problem is, I can't seem to make the https://graph.microsoft.com/beta/deviceAppManagement/mobileApps request properly - I always get 401. When making the same request via the Graph API Explorer it works fine.
I tried fixing my permissions, and I'm kinda stuck getting the correct token.
I did the following steps with an admin account, on both the "common" and our own tennant:
Called the admin consent - https://login.microsoftonline.com/nativeflow.onmicrosoft.com/adminconsent?client_id=<ID>&redirect_uri=<URI>
Got authorization from the user - https://login.microsoftonline.com/common/oauth2/v2.0/authorize?client_id=<ID>&response_type=code&redirect_uri=<URI>&response_mode=query&scope=DeviceManagementApps.ReadWrite.All
POST request to get the actual token -
https://login.microsoftonline.com/nativeflow.onmicrosoft.com/oauth2/v2.0/token
with the following body:
client_id: <ID>
scope: https://graph.microsoft.com/.default
client_secret: <secret>
grant_type: client_credentials
requested_token_use: on_behalf_of
code: <The code I got in step 2>
I tried changing the scope in step 3 to https://graph.microsoft.com/DeviceManagementApps.ReadWrite.All or simply to DeviceManagementApps.ReadWrite.All, but it says that it's not a valid scope.
I got a token in step 3, but when I try calling the actual API I receive this error:
{
ErrorCode:"Forbidden",
Message:{
_version: 3,
Message: "An error has occurred - Operation ID (for customer support): 00000000-0000-0000-0000-000000000000 - Activity ID: 7b5c3841-976d-4509-b946-f7fdabd047d7 - Url: https://fef.msub02.manage.microsoft.com/StatelessAppMetadataFEService/deviceAppManagement/mobileApps?api-version=5018-05-02",
CustomApiErrorPhrase: "",
RetryAfter: null,
ErrorSourceService: "",
HttpHeaders: {"WWW-Authenticate":"Bearer realm=urn:intune:service,f0f3c450-59bf-4f0d-b1b2-0ef84ddfe3c7"}
},
Target:null,
Details:null,
InnerError:null,
InstanceAnnotations:[]
}
So yeah, I'm pretty much stuck. Anyone have any experience with it? I've tried making the calls in Postman, curl and via code, but nothing works.
Cheers :)

Answer 1

You have a couple issues going on:
You're using the Authorization Code Grant workflow but requesting Client Credentials.
The scope Device.ReadWrite.All is an application scope, it is only applicable to Client Credentials. It isn't a valid Delegated scope so it will return an error when you attempt to authenticate a user (aka delegate) using Device.ReadWrite.All.
Your body is using key:value but it should be using standard form encoding (key=value).
To get this working, you need to request a token without a user. This is done by skipping your 2nd step and moving directly to retrieving a token (body line-breaks are only for readability):
POST https://login.microsoftonline.com/nativeflow.onmicrosoft.com/oauth2/v2.0/token
Content-Type: application/x-www-form-urlencoded
client_id={id}
&client_secret={secret}
&scope=https%3A%2F%2Fgraph.microsoft.com%2F.default
&grant_type=client_credentials