Add covert-dtls to proxy and client with flags

proxy/main.go

@@ -46,6 +46,8 @@ func main() {
 	verboseLogging := flag.Bool("verbose", false, "increase log verbosity")
 	ephemeralPortsRangeFlag := flag.String("ephemeral-ports-range", "", "Set the `range` of ports used for client connections (format:\"<min>:<max>\").\nIf omitted, the ports will be chosen automatically.")
 	versionFlag := flag.Bool("version", false, "display version info to stderr and quit")
+	dtlsRandomize := flag.Bool("dtls-randomize", false, "randomize DTLS client hello")
+	dtlsMimic := flag.Bool("dtls-mimic", false, "mimic DTLS client hello of Chrome and Firefox")
 
 	var ephemeralPortsRange []uint16 = []uint16{0, 0}
 
@@ -64,6 +66,10 @@ func main() {
 		log.Fatal("Cannot keep local address candidates when outbound address is specified")
 	}
 
+	if *dtlsMimic && *dtlsRandomize {
+		log.Fatal("Cannot both Randomize and Mimic DTLS client hello")
+	}
+
 	eventLogger := event.NewSnowflakeEventDispatcher()
 
 	if *ephemeralPortsRangeFlag != "" {
@@ -112,6 +118,8 @@ func main() {
 		AllowNonTLSRelay:                *allowNonTLSRelay,
 
 		SummaryInterval: *summaryInterval,
+		DTLSRandomize:   *dtlsRandomize,
+		DTLSMimic:       *dtlsMimic,
 	}
 
 	var logOutput = io.Discard