private async Task HandshakeAsync()
{
var encryptedServerKey = rsaCryptography.Encrypt(clientSettings.PublicRsaKey, desCryptography.Key);
var signature = rsaCryptography.Sign(clientSettings.PrivateRsaKey, encryptedServerKey);
var rawEncryptedServerKeyLength = BitConverter.GetBytes(encryptedServerKey.Length);
Array.Reverse(rawEncryptedServerKeyLength);
var requestDataLength = encryptedServerKey.Length + signature.Length + rawEncryptedServerKeyLength.Length;
var requestData = new Byte[requestDataLength];
Array.Copy(rawEncryptedServerKeyLength, 0, requestData, 0, 4);
Array.Copy(encryptedServerKey, 0, requestData, 4, encryptedServerKey.Length);
Array.Copy(signature, 0, requestData, 4 + encryptedServerKey.Length, signature.Length);
var rawResponse = await SendRequestAsync(requestData, ConnectionMode.Assymmetric);
var response = Convert.ToBase64String(rawResponse);
}