Golang crypto/tls.Listen and NewListener functions example

22nd June 2015

package crypto/tls

Listen creates a TLS listener accepting connections on the given network address using net.Listen. The configuration config must be non-nil and must have at least one certificate.

NewListener creates a Listener which accepts connections from an inner Listener and wraps each connection with Server. The configuration config must be non-nil and must have at least one certificate.

For this example to work, first you need to have pem and key files. On Linux/Unix machines, you can generate the files with openssl

openssl req -new -nodes -x509 -out server.pem -keyout server.key -days 365

Golang Listen() and NewListener() functions usage example

 package main

 import (
 "fmt"
 "net"
 "os"
 "crypto/tls"
 "crypto/rand"
 )

 func main() {

 certificate, err := tls.LoadX509KeyPair("server.pem", "server.key")

 if err != nil {
 fmt.Println(err)
 os.Exit(1)
 }


 // For ClientAuth : tls.RequireAnyClientCert. See http://golang.org/pkg/crypto/tls/#ClientAuthType
 config := tls.Config{Certificates : []tls.Certificate{certificate}, ClientAuth: tls.RequireAnyClientCert}
 config.Rand = rand.Reader


 var newnetlistener, netlistener net.Listener

 // The network net must be a stream-oriented network: "tcp", "tcp4", "tcp6", "unix" or "unixpacket".
 // see http://golang.org/pkg/net/#Listen
 var network = "tcp"

 var laddr = "0.0.0.0:8000" // laddr = address to listen

 netlistener, err = tls.Listen(network, laddr, &config)

 if err != nil {
 fmt.Println(err)
 os.Exit(1)
 }

 fmt.Println("[Server Status] : Listening")

 newnetlistener = tls.NewListener(netlistener, &config) // New Listener

 fmt.Println("[Server Status] : New Listener Listening")


 for {
 conn, err := netlistener.Accept()
 newconn, err := newnetlistener.Accept()

 if err != nil {
 fmt.Println(err)
 }

 fmt.Printf("[Server Status] : Accepted connection from %s", conn.RemoteAddr())
 fmt.Printf("[Server Status] : Accepted connection from %s", newconn.RemoteAddr())
 }

 }

Output :