main.go

package main

import (
	"flag"
	"log"

	"github.com/giuliocomi/knockandgo/certs"
	"github.com/giuliocomi/knockandgo/network"
	"github.com/giuliocomi/knockandgo/utility"
)

var (
	k_port               = flag.Int("k", 80, "port to open via knock technique")
	server_port          = flag.Int("s", 8080, "server port")
	server_ip            = flag.String("a", "localhost", "server address (IP)")
	ip_to_whitelist      = flag.String("i", "127.0.0.1", "the source IP to whitelist for the tcp forwarding connections")
	max_forwarding_ports = flag.Int("f", 5, "number of maximum tcp wrappers to instantiate")
	modality             = flag.String("m", "c", "modality of operation: server (s) or client (c)")
	certpath             = flag.String("c", "./certs/", "the path to the PEM certificate (public in case of client, private in case of server")
	timeout              = flag.Int("t", 86400, "timeout in seconds")
	knockable_ports      []int
)

func main() {
	flag.Parse()

	// load and validate the whitelisted knockable ports
	args, err := utility.SliceAtoi(flag.Args())
	if err != nil {
		log.Println(err)
	}

	for _, arg := range args {
		knockable_ports = append(knockable_ports, arg)
	}

	//check if the necessary certificates are in the correct path (/certs)
	areCertificatePresent := certs.CheckCerts(*certpath, *modality)
	if !areCertificatePresent {
		log.Println("The necessary certificates are missing...")
		certs.HandleCert(*certpath)
	}

	//launch the client or server instance
	switch string(*modality) {
	case string("s"):
		s := network.GetUDPServer()
		s.SetUdpServer(*server_port, knockable_ports, *max_forwarding_ports, *certpath, *timeout)
		s.Run()
	case string("c"):
		c := network.NewUdpClient(*server_ip, *server_port, *k_port, *certpath, *timeout, *ip_to_whitelist)
		c.Run()
	default:
		log.Println("unkown modality")
	}
}