(Xojo Plugin) Microsoft Graph OAuth2 Client Credentials Grant Flow

Demonstrates how to get a Microsoft Graph access token using the Client Credentials Grant Flow.

You can use the OAuth 2.0 client credentials grant specified in RFC 6749, sometimes called two-legged OAuth, to access web-hosted resources by using the identity of an application. This type of grant is commonly used for server-to-server interactions that must run in the background, without immediate interaction with a user. These types of applications are often referred to as daemons or service accounts.

For more information, see https://docs.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-client-creds-grant-flow

Chilkat Xojo Plugin Download Xojo Plugin for Windows, Linux, Mac OS X, and ARM, ARM64

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

Dim http As New Chilkat.Http

Dim req As New Chilkat.HttpRequest
req.AddParam "client_secret","CLIENT_SECRET"
req.AddParam "client_id","CLIENT_ID"
// Don't know if the scopes valid for the client credentials grant are different than the scopes for the 3-legged Authorization Code Grant...
req.AddParam "scope","https://graph.microsoft.com/.default"
req.AddParam "grant_type","client_credentials"

// Use your own tenant ID, for example 4d8fdd66-66d1-43b0-ae5c-e31b4b7de5cd
Dim url As String
url = "https://login.microsoftonline.com/TENANT_ID/oauth2/v2.0/token"
Dim resp As Chilkat.HttpResponse
resp = http.PostUrlEncoded(url,req)
If (http.LastMethodSuccess <> True) Then
    System.DebugLog(http.LastErrorText)
    Return
End If

Dim statusCode As Int32
statusCode = resp.StatusCode
System.DebugLog("Response status code = " + Str(statusCode))

Dim json As New Chilkat.JsonObject
Dim success As Boolean
success = json.Load(resp.BodyStr)

json.EmitCompact = False
System.DebugLog(json.Emit())

// Sample successful output:

// {
//   "token_type": "Bearer",
//   "expires_in": 3599,
//   "ext_expires_in": 3599,
//   "access_token": "eyJ0eX...K0jOERg"
// }

If (statusCode = 200) Then
    success = json.WriteFile("qa_data/tokens/msGraphClientCredentialsToken.json")
    System.DebugLog("Success.")
Else
    System.DebugLog("Failed.")
End If