Vert.x OIDC Missing scope in authorize request

Question

I have the following code to create an AzureAD auth provider.

val options = OAuth2Options()
            .setClientId(clientId)
            .setClientSecret(clientSecret)
            .setTenant(guid)
            .setSite("https://login.microsoftonline.com/{tenant}/v2.0")
val authProvider = AzureADAuth.discover(vertx, options).await()

Now if I try to login using my browser I get the following error on the Microsoft Login page:

AADSTS900144: The request body must contain the following parameter: 'scope'.

Looking at the URL it is true that there is no scope parameter:

https://login.microsoftonline.com/xx-xx-xx-xx-xx/oauth2/v2.0/authorize?state=duF2O-eO&redirect_uri=http%3A%2F%2Flocalhost%3A9339%2Fazure-callback&response_type=code&client_id=xx-xx-xx-xx-xx

When I do the same with cognito instead of Azure it works without a problem, even though there is also no scope in the request.

What am I missing? Is this on Vert.x side or Azure?

Answer 1

The error message is being bubbled up from Azure Active Directory Service:

AADSTS900144: The request body must contain the following parameter: 'scope'.

Azure always requires at least 1 scope to be provided. Depending on how you're using vert.x you can do it in 2 ways:

If you're using the auth API directly, you specify the required scopes in the credentials request:

oauth2
  .authenticate(
    new Oauth2Credentials()
      // flow specific options +
      .addScope("a")
      .addScope("b")

If you're using it from a vertx-web application you can specify the required scopes on the oauth2 handler:

OAuth2AuthHandler oauth2 = OAuth2AuthHandler
  .create(vertx, authProvider)
  // these are the scopes
  .withScope("a")
  .withScope("b");

The scopes are specific for the provider so you will need to consult Azure documentation to know which ones you should use:

https://learn.microsoft.com/en-us/azure/active-directory/develop/v2-overview