(Swift 3,4,5...) 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 Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

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

    let http = CkoHttp()!

    let req = CkoHttpRequest()!
    req.addParam("client_secret", value: "CLIENT_SECRET")
    req.addParam("client_id", value: "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", value: "https://graph.microsoft.com/.default")
    req.addParam("grant_type", value: "client_credentials")

    // Use your own tenant ID, for example 4d8fdd66-66d1-43b0-ae5c-e31b4b7de5cd
    var url: String? = "https://login.microsoftonline.com/TENANT_ID/oauth2/v2.0/token"
    var resp: CkoHttpResponse? = http.postUrlEncoded(url, req: req)
    if http.lastMethodSuccess != true {
        print("\(http.lastErrorText!)")
        return
    }

    var statusCode: Int = resp!.statusCode.intValue
    print("Response status code = \(statusCode)")

    let json = CkoJsonObject()!
    json.load(resp!.bodyStr)
    resp = nil

    json.emitCompact = false
    print("\(json.emit()!)")

    // Sample successful output:

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

    if statusCode == 200 {
        json.writeFile("qa_data/tokens/msGraphClientCredentialsToken.json")
        print("Success.")
    }
    else {
        print("Failed.")
    }


}