public string GetLoginBase64(int userId) { string privateKey = Encoding.UTF8.GetString(Resources.privatekey); RSAParameters p = RSAHelper.ConvertFromPemPrivateKey(privateKey); string start = "01FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00"; string end = "010101010101010101010101010101010101010101010101010101010101010155914510010403030101"; string id = start + userId.ToString("X8") + end; int l = id.Length; byte[] bufId = (new BigInteger(id, 16)).getBytes(); byte[] mm = DataTranslate.HexStringToByte(id); byte[] bufCode = RSAHelper.RsaDecrypt(mm, p.D, p.Modulus); string base64 = Convert.ToBase64String(bufCode); return(base64); }