func (conn *TCPConn) ReadIPPacket(b []byte) (n int, err error) {
ivheader := make([]byte, cipher.IVSize+IPHeaderSize)
if _, err = io.ReadFull(conn, ivheader); err != nil {
glog.V(3).Infoln("fail to read iv and encrypted header", err)
return
}
dec := cipher.NewDecrypter(conn.cipher, ivheader[:cipher.IVSize])
dec.Decrypt(b[:IPHeaderSize], ivheader[cipher.IVSize:])
n = int(binary.BigEndian.Uint16(b[2:4]))
payload := make([]byte, n-IPHeaderSize)
if _, err = io.ReadFull(conn, payload); err != nil {
glog.V(3).Infoln("fail to read encrypted payload", err)
return
}
dec.Decrypt(b[IPHeaderSize:n], payload)
return
}
func recieve(cph *cipher.Cipher, tcpConn net.Conn, data interface{}) (err error) {
iv := make([]byte, cipher.IVSize)
if _, err = io.ReadFull(tcpConn, iv); err != nil {
glog.V(3).Infoln("fail to read iv", err)
return
}
dec := cipher.NewDecrypter(cph, iv)
encrypted := make([]byte, binary.Size(data))
if _, err = io.ReadFull(tcpConn, encrypted); err != nil {
glog.V(3).Infoln("fail to read encrypted data", err)
return
}
decrypted := make([]byte, len(encrypted))
dec.Decrypt(decrypted, encrypted)
if err = binary.Read(bytes.NewBuffer(decrypted), binary.BigEndian, data); err != nil {
glog.V(3).Infoln("fail to unmarshal data", err)
return
}
glog.V(3).Infoln("data recieved", data)
return
}