From 3b720c081ba1906dc6d64345c233e145f056f9ff Mon Sep 17 00:00:00 2001
From: Ylian Saint-Hilaire <ysainthilaire@hotmail.com>
Date: Wed, 9 Jun 2021 22:33:58 -0700
Subject: [PATCH] Added WebSocket masking.

---
 WebSocketClient.cs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/WebSocketClient.cs b/WebSocketClient.cs
index 950344c..61fd8a9 100644
--- a/WebSocketClient.cs
+++ b/WebSocketClient.cs
@@ -62,6 +62,7 @@ namespace MeshCentralRouter
         public long PendingSendLength { get { return (pendingSendBuffer == null)? 0 : pendingSendBuffer.Length; } }
         private bool readPaused = false;
         private bool shouldRead = false;
+        private RNGCryptoServiceProvider CryptoRandom = new RNGCryptoServiceProvider();
 
         // Outside variables
         public object tag = null;
@@ -644,6 +645,12 @@ namespace MeshCentralRouter
             // Check that everything is ok
             if (len < 0) { Dispose(); return 0; }
 
+            // Set the mask to a cryptographic random value and XOR the data
+            byte[] rand = new byte[4];
+            CryptoRandom.GetBytes(rand);
+            Array.Copy(rand, 0, buf, 10, 4);
+            for (int x = 0; x < len; x++) { buf[x + 14] ^= rand[x % 4]; }
+
             if (len < 126)
             {
                 // Small fragment