AADSTS50013: Assertion failed signature validation. Key was found, but use of the key to verify the signature failed.

Question

I am trying to authenticate on behalf of a user using an access token.

Flow: My backend receives an access token from the frontend (next js using the AzureAd provider for NextAuth). I want to use that access token to acquire an access token to use with microsoft graph but I get the "failed signature validation" error.

from msal import ConfidentialClientApplication

app = ConfidentialClientApplication(
   client_id="d0d65cdc-42af-4539-932b-f46ed114b1a1",
   client_credential="

Answer 1

Hi @Aashutosh Aryal , thanks for reaching us.

I understand you are trying to authenticate on behalf of a user using an access token.

When you authenticate on behalf of a user using an access token, you have to set Application ID URI as api://{client_id}

Go to Azure Active Directory -> App Registrations -> select your application -> Expose an API -> add Application ID URI -> Click on save.

Select Add a scope button and enter the required values ->make sure state as enabled -> click on Add Scope button on the bottom to save this scope.

Select API permisisons -> Click Add Permission ->Search with your application Id -> In the Delegated permissions section, ensure that the right permissions are checked -> Click on Add permissions button.

Thanks,

Navya.

Hope this helps. Do let us know if you any further queries.