public OAuth20ConstructedAssertion ConstructAssertion(string userName)
{
// Get the UTC Date Timestamp
string timestamp = DateTime.UtcNow.ToString("s") + "Z";
// Setup the Assertion String
string assertion = String.Format("{0}|{1}|{2}|{3}|{4}|{5}", clientName, publicKey, applicationId, clientString, userName, timestamp);
// Generate the CMAC used for Assertion Security
string cmac = OAuthUtilities.GenerateCmacHEX(privateKey, assertion);
// Add the CMAC to the Assertion String
string assertionFinal = String.Format("{0}|{1}", assertion, cmac);
return(assertionFinal);
}