Merge pull request #4 from Tristan971/add-sni-support

Add SNI support

internal/cli.go

@@ -16,11 +16,13 @@ func (s *SSLHandshake) SetUsage() {
 		fmt.Println()
 		fmt.Println("Options:")
 		fmt.Printf("  -t <timeout>   SSL handshake timeout in milliseconds (default: %d)\n", s.Config.Timeout)
+		fmt.Printf("  -n <name>      Server name indication value (default: unset)\n")
 		fmt.Printf("  -c <count>     Stop after <count> SSL handshakes (default: %d)\n", s.Config.StopCount)
 		fmt.Printf("  -i <interval>  Wait <interval> milliseconds between SSL handshakes (default: %d)\n", s.Config.Interval)
 		fmt.Println()
 		fmt.Println("Examples:")
 		fmt.Printf("  %s tuladhar.github.com:443\n", s.Metadata.Name)
+		fmt.Printf("  %s -n dns.google 8.8.8.8:443\n", s.Metadata.Name)
 		fmt.Printf("  %s -c 3 -i 500 tuladhar.github.com:443\n", s.Metadata.Name)
 		fmt.Printf("  %s -t 500 imap.gmail.com:993\n", s.Metadata.Name)
 	}
@@ -30,6 +32,7 @@ func (s *SSLHandshake) ParseFlag() {
 	flag.Int64Var(&s.Config.Timeout, "t", s.Config.Timeout, "")
 	flag.Int64Var(&s.Config.StopCount, "c", s.Config.StopCount, "")
 	flag.Int64Var(&s.Config.Interval, "i", s.Config.Interval, "")
+	flag.StringVar(&s.Config.ServerName, "n", "", "")
 
 	flag.Parse()
 	if len(flag.Args()) != 1 {

internal/sslhandshake.go

@@ -16,10 +16,11 @@ type SSLHandshakeMetadata struct {
 }
 
 type SSLHandshakeConfig struct {
-	Endpoint  string
-	Interval  int64
-	Timeout   int64
-	StopCount int64
+	Endpoint   string
+	Interval   int64
+	ServerName string
+	StopCount  int64
+	Timeout    int64
 }
 
 type SSLHandshakeState struct {
@@ -53,6 +54,9 @@ func (s *SSLHandshake) DoHandshake() (int64, uint16, int64, error) {
 	tlsConfig := tls.Config{
 		InsecureSkipVerify: true,
 	}
+	if s.Config.ServerName != "" {
+		tlsConfig.ServerName = s.Config.ServerName
+	}
 
 	tcpConn, tcpTime, tcpErr := s.EstablishTcp()
 	if tcpErr != nil {

main.go

@@ -13,10 +13,11 @@ func main() {
 			URL:         "https://github.com/tuladhar/ssl-handshake",
 		},
 		Config: &sslhandshake.SSLHandshakeConfig{
-			Endpoint:  "",
-			Interval:  1000,
-			Timeout:   5000,
-			StopCount: 0,
+			Endpoint:   "",
+			Interval:   1000,
+			ServerName: "",
+			StopCount:  0,
+			Timeout:    5000,
 		},
 		State: &sslhandshake.SSLHandshakeState{},
 	}