I am developing a rather simple application that retrieves files from SharePoint using the REST Office 365 API. This is a batch job running in the background with no user interface so the following simple 2-step flow is what I'm doing:
(1) Requesting an Access Token from Azure AD (supplying client ID, client secret, resource, and grant_type=client_credentials)
(2) Invoke the SharePoint API (https://{base url}/_api/v1.0/Files) using the "Authorization: Bearer <access_token>" as a request header .
That process seems pretty straightforward and sounds simple but I keep getting the following error :
401 Unauthorized
x-ms-diagnostics: 3001000;reason="There has been an error authenticating the request.";category="invalid_client"
Any idea what the problem is and how this can be resolved ? I have been stuck on this for days now. I would REALLY appreciate somebody's help with this. Thanks.
- CW