adalrepro.cs

// problem ? 
// Microsoft.IdentityModel.Clients.ActiveDirectory.3.9.302111717-alpha\lib\net45\Microsoft.IdentityModel.Clients.ActiveDirectory.dll 

private static X509Certificate2 FromStore(string certThumbPrint)
{
    var store = new X509Store(storeName: StoreName.My, storeLocation: StoreLocation.CurrentUser);
    try
    {
        store.Open(OpenFlags.ReadOnly);
        var cert = store.Certificates.Find(
                findType: X509FindType.FindByThumbprint,
                findValue: certThumbPrint,
                validOnly: false)[0];
        return cert;
    }
    catch { try { if (store != null) { store.Close(); } } catch (Exception) { ; } throw; }
}

public static string GetOAuthTokenFromAAD()
{
    const string ADALServiceURL = "https://login.microsoftonline.com";
    var adTenant = "deadbeef-.........";
    var applicationId = "deadbeef-.......";
    var CertificateThumbprint = "B8789A48A020FB1F5589C9ACAF63A4EBFFF5FA1C";

    var authenticationContext = new AuthenticationContext($"{ ADALServiceURL}/{adTenant}");
    X509Certificate2 cert = FromStore(CertificateThumbprint);
    var certCred = new ClientAssertionCertificate(clientId: applicationId, certificate: cert);
    AuthenticationResult token = authenticationContext.AcquireTokenAsync(
        resource: "https://management.core.windows.net/", 
        clientCertificate: certCred).Result;

    return token.AccessToken;
}