Zoraxy/acme.go

package main

import (
	"fmt"
	"io/ioutil"
	"log"
	"math/rand"
	"net"
	"net/http"
	"regexp"
	"strconv"
	"time"

	"imuslab.com/zoraxy/mod/acme"
	"imuslab.com/zoraxy/mod/dynamicproxy"
)

/*
	acme.go

	This script handle special routing required for acme auto cert renew functions
*/

var acmeHandler *acme.ACMEHandler

// Helper function to generate a random port above a specified value
func getRandomPort(minPort int) int {
	return rand.Intn(65535-minPort) + minPort
}

// Helper function to check if a port is in use
func isPortInUse(port int) bool {
	address := fmt.Sprintf(":%d", port)
	listener, err := net.Listen("tcp", address)
	if err != nil {
		return true // Port is in use
	}
	defer listener.Close()
	return false // Port is not in use
}

func initACME() *acme.ACMEHandler {
	log.Println("Start initializing ACME")
	rand.Seed(time.Now().UnixNano())
	// Generate a random port above 30000
	port := getRandomPort(30000)

	// Check if the port is already in use
	for isPortInUse(port) {
		port = getRandomPort(30000)
	}

	return acme.NewACME("[email protected]", "https://acme-staging-v02.api.letsencrypt.org/directory", strconv.Itoa(port))
}

func acmeRegisterSpecialRoutingRule() {
	log.Println("Assigned temporary port:" + acmeHandler.Getport())

	err := dynamicProxyRouter.AddRoutingRules(&dynamicproxy.RoutingRule{
		ID: "acme-autorenew",
		MatchRule: func(r *http.Request) bool {
			found, _ := regexp.MatchString("/.well-known/*", r.RequestURI)
			return found
		},
		RoutingHandler: func(w http.ResponseWriter, r *http.Request) {

			req, err := http.NewRequest(http.MethodGet, "http://localhost:"+acmeHandler.Getport()+r.RequestURI, nil)
			req.Host = r.Host
			if err != nil {
				fmt.Printf("client: could not create request: %s\n", err)
			}
			res, err := http.DefaultClient.Do(req)
			if err != nil {
				fmt.Printf("client: error making http request: %s\n", err)
			}

			resBody, err := ioutil.ReadAll(res.Body)
			if err != nil {
				fmt.Printf("error reading: %s\n", err)
			}
			w.Write(resBody)
		},
		Enabled: true,
	})

	if err != nil {
		log.Println("[Err] " + err.Error())
	}
}