(Lianja) 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

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

loHttp = createobject("CkHttp")

loReq = createobject("CkHttpRequest")
loReq.AddParam("client_secret","CLIENT_SECRET")
loReq.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...
loReq.AddParam("scope","https://graph.microsoft.com/.default")
loReq.AddParam("grant_type","client_credentials")

// Use your own tenant ID, for example 4d8fdd66-66d1-43b0-ae5c-e31b4b7de5cd
lcUrl = "https://login.microsoftonline.com/TENANT_ID/oauth2/v2.0/token"
loResp = loHttp.PostUrlEncoded(lcUrl,loReq)
if (loHttp.LastMethodSuccess <> .T.) then
    ? loHttp.LastErrorText
    release loHttp
    release loReq
    return
endif

lnStatusCode = loResp.StatusCode
? "Response status code = " + str(lnStatusCode)

loJson = createobject("CkJsonObject")
loJson.Load(loResp.BodyStr)
release loResp

loJson.EmitCompact = .F.
? loJson.Emit()

// Sample successful output:

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

if (lnStatusCode = 200) then
    loJson.WriteFile("qa_data/tokens/msGraphClientCredentialsToken.json")
    ? "Success."
else
    ? "Failed."
endif



release loHttp
release loReq
release loJson