From fe8e9c194784d0cac0ab807880dcac52ad73b0ab Mon Sep 17 00:00:00 2001
From: Shreyas Zare <shreyas@technitium.com>
Date: Sun, 3 Jan 2021 15:56:44 +0530
Subject: [PATCH] DomainTree: returning null in ConvertKeyToLabel() when domain
 length is less than 1.

---
 DnsServerCore/Dns/Zones/DomainTree.cs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/DnsServerCore/Dns/Zones/DomainTree.cs b/DnsServerCore/Dns/Zones/DomainTree.cs
index a1b48a45..4437a5d0 100644
--- a/DnsServerCore/Dns/Zones/DomainTree.cs
+++ b/DnsServerCore/Dns/Zones/DomainTree.cs
@@ -1,6 +1,6 @@
 /*
 Technitium DNS Server
-Copyright (C) 2020  Shreyas Zare (shreyas@technitium.com)
+Copyright (C) 2021  Shreyas Zare (shreyas@technitium.com)
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -158,7 +158,11 @@ namespace DnsServerCore.Dns.Zones
 
         protected static string ConvertKeyToLabel(byte[] key, int startIndex)
         {
-            byte[] domain = new byte[key.Length - startIndex];
+            int length = key.Length - startIndex;
+            if (length < 1)
+                return null;
+
+            byte[] domain = new byte[length];
             int i;
             int k;