public static byte[] BuildQrBody(ClientListener responseTo, byte[] pcPublicEcdh) { var qrBody = new List <byte>(); qrBody.AddRange(BitConverter.GetBytes(pcPublicEcdh.Length)); qrBody.AddRange(pcPublicEcdh); var userData = new List <byte>(); userData.AddRange(responseTo.ComputeHeader()); qrBody.AddRange(BitConverter.GetBytes(userData.Count)); qrBody.AddRange(userData); return(qrBody.ToArray()); }