From 0e75c9fddd2d2508ab9069d496cd3feb905b7bfc Mon Sep 17 00:00:00 2001
From: sta <sta.blockhead@gmail.com>
Date: Sat, 17 Mar 2018 18:09:30 +0900
Subject: [PATCH] [Fix] LWS is refused

---
 websocket-sharp/Net/HttpListenerRequest.cs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/websocket-sharp/Net/HttpListenerRequest.cs b/websocket-sharp/Net/HttpListenerRequest.cs
index 29bd6e02..3526126d 100644
--- a/websocket-sharp/Net/HttpListenerRequest.cs
+++ b/websocket-sharp/Net/HttpListenerRequest.cs
@@ -626,6 +626,12 @@ namespace WebSocketSharp.Net
 
     internal void AddHeader (string headerField)
     {
+      var start = headerField[0];
+      if (start == ' ' || start == '\t') {
+        _context.ErrorMessage = "Invalid header field";
+        return;
+      }
+
       var colon = headerField.IndexOf (':');
       if (colon < 1) {
         _context.ErrorMessage = "Invalid header field";