ReubenBond

public static string GetSignature(string masterKey, string resourceId, string resourceType, string xDate = null, string date = null)
{
  if (string.IsNullOrEmpty(xDate) && string.IsNullOrEmpty(date))
  {
   throw new ArgumentException("Either xDate or date must be provided.");
  }

  const string AuthorizationFormat = "type={0}&ver={1}&sig={2}";
  const string MasterToken = "master";
  const string TokenVersion = "1.0";