string aadTenant = ClientConfiguration.Default.ActiveDirectoryTenant;
    string aadClientAppId = ClientConfiguration.Default.ActiveDirectoryClientAppId;
    string aadResource = ClientConfiguration.Default.ActiveDirectoryResource;

    AuthenticationContext authenticationContext = new AuthenticationContext(aadTenant);

    // OAuth through username and password.
    string username = ClientConfiguration.Default.UserName;
    string password = ClientConfiguration.Default.Password;

    // Get token object
    var userCredential = new UserPasswordCredential(username, password);
    AuthenticationResult authenticationResult = authenticationContext.AcquireTokenAsync(
    aadResource,
    aadClientAppId,
    userCredential).Result;