func tcpClient(addr string, key, message []byte) ([]byte, error) {
tcpaddr, err := net.ResolveTCPAddr("tcp", addr)
if err != nil {
return nil, err
}
ciphertext, err := libsodium.EncryptData(key, message)
if err != nil {
return nil, err
}
tcpconn, err := net.DialTCP("tcp", nil, tcpaddr)
if err != nil {
return nil, err
}
defer tcpconn.Close()
tcpconn.SetWriteDeadline(time.Now().Add(time.Duration(20) * time.Second))
_, err = tcpconn.Write(netstring.Marshall(ciphertext))
if err != nil {
return nil, err
}
tcpconn.SetReadDeadline(time.Now().Add(time.Duration(20) * time.Second))
bufReader := bufio.NewReader(tcpconn)
var buf bytes.Buffer
var ip []byte
for {
rData, err := bufReader.ReadBytes(',')
if err != nil {
if err == io.EOF {
return nil, err
}
buf.Write(rData)
continue
}
buf.Write(rData)
ip, err = netstring.Unmarshall(buf.Bytes())
if err != nil {
if err == netstring.ErrNsLenNotEqaulOrgLen {
continue
}
return nil, err
}
break
}
return ip, nil
}
func udpClient(addr string, key, message []byte) error {
udpaddr, err := net.ResolveUDPAddr("udp", addr)
if err != nil {
return err
}
ciphertext, err := libsodium.EncryptData(key, message)
if err != nil {
return err
}
udpconn, err := net.DialUDP("udp", nil, udpaddr)
if err != nil {
return err
}
defer udpconn.Close()
_, err = udpconn.Write(netstring.Marshall(ciphertext))
if err != nil {
return err
}
return nil
}
