From e0e33e12d689e2d6607122b270c7ab068acf7789 Mon Sep 17 00:00:00 2001
From: Qian Wang <cbeuw.andy@gmail.com>
Date: Fri, 2 Aug 2019 20:06:41 +0100
Subject: [PATCH] Fix non random GREASE generation

---
 internal/client/chrome.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/internal/client/chrome.go b/internal/client/chrome.go
index 5d0c04b..8c36b13 100644
--- a/internal/client/chrome.go
+++ b/internal/client/chrome.go
@@ -3,10 +3,9 @@
 package client
 
 import (
+	"crypto/rand"
 	"encoding/binary"
 	"encoding/hex"
-	"math/rand"
-	"time"
 )
 
 type Chrome struct{}
@@ -14,8 +13,9 @@ type Chrome struct{}
 func makeGREASE() []byte {
 	// see https://tools.ietf.org/html/draft-davidben-tls-grease-01
 	// This is exclusive to Chrome.
-	rand.Seed(time.Now().UnixNano())
-	sixteenth := rand.Intn(16)
+	var one [1]byte
+	rand.Read(one[:])
+	sixteenth := one[0] % 16
 	monoGREASE := byte(sixteenth*16 + 0xA)
 	doubleGREASE := []byte{monoGREASE, monoGREASE}
 	return doubleGREASE