From 15c0e975ca66cc8ce3fb96e2943d04fb8b7a42de Mon Sep 17 00:00:00 2001
From: liberal-boy <liberal-boy@protonmail.com>
Date: Mon, 15 Apr 2019 23:21:47 +0800
Subject: [PATCH] enable TLS 1.3 by default

---
 transport/internet/tls/tls.go | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/transport/internet/tls/tls.go b/transport/internet/tls/tls.go
index dd9a0bb80..dea950d15 100644
--- a/transport/internet/tls/tls.go
+++ b/transport/internet/tls/tls.go
@@ -4,6 +4,7 @@ package tls
 
 import (
 	"crypto/tls"
+	"os"
 
 	"v2ray.com/core/common/buf"
 	"v2ray.com/core/common/net"
@@ -65,3 +66,9 @@ func Server(c net.Conn, config *tls.Config) net.Conn {
 	tlsConn := tls.Server(c, config)
 	return &conn{Conn: tlsConn}
 }
+
+func init() {
+	// opt-in TLS 1.3 for Go1.12
+	// TODO: remove this line when Go1.13 is released.
+	_ = os.Setenv("GODEBUG", os.Getenv("GODEBUG")+",tls13=1")
+}