TLS enabled HTTP Server in Go

server.go

package main

import (
  "crypto/tls"
  "fmt"
  "log"
  "net"
  "net/http"
)

func handler(w http.ResponseWriter, req *http.Request) {
  w.Header().Set("Content-Type", "text/plain")
  w.Write([]byte("This an example server.\n")
}

func main() {
  http.HandleFunc("/", handler)
  
  server := &http.Server{Addr: ":8000", Handler: nil}
  tlsConfig := &tls.Config{}
  tlsConfig.ClientAuth = tls.RequireAnyClientCert
  tlsConfig.NextProtos = []string{"http/1.1"}
  
  var err error
  tlsConfig.Certificates = make([]tls.Certificate, 1)
  tlsConfig.Certificates[0], err = tls.LoadX509KeyPair("public_cert.pem", "private_key.key")
  if err != nil {
    log.Fatal(err)
  }
  
  conn, err := net.Listen("tcp", server.Addr)
  if err != nil {
    log.Fatal(err)
  }
  
  tlsListener := tls.NewListener(conn, tlsConfig)
  server.Server(tlsListener)
}