public bool SHAValidateSign(string originalstring, byte[] fileSignature, byte[] pubKey)
        {

            var cert = new X509Certificate2();
            try
            {
                cert = new X509Certificate2(pubKey, "");
            }
            catch (System.Security.Cryptography.CryptographicException e)
            {
                var a = e.InnerException;
            }

            var rsaCryptoIPT = (RSACryptoServiceProvider)cert.PublicKey.Key;
            var sha1 = new SHA1CryptoServiceProvider();
            ASCIIEncoding encoder = new ASCIIEncoding();

            return (!rsaCryptoIPT.VerifyData(encoder.GetBytes(originalstring), sha1, fileSignature));
        }