class Net::SSH::Transport::Kex::EcdhSHA2NistP256

def build_signature_buffer(result)
  response = Net::SSH::Buffer.new
  response.write_string data[:client_version_string],
                        data[:server_version_string],
                        data[:client_algorithm_packet],
                        data[:server_algorithm_packet],
                        result[:key_blob],
                        ecdh.public_key.to_bn.to_s(2),
                        result[:server_ecdh_pubkey]
  response.write_bignum result[:shared_secret]
  response
end