diff --git a/SMBLibrary.Tests/Client/SMB2ClientTests.cs b/SMBLibrary.Tests/Client/SMB2ClientTests.cs
index 40e88b3e..a081a307 100644
--- a/SMBLibrary.Tests/Client/SMB2ClientTests.cs
+++ b/SMBLibrary.Tests/Client/SMB2ClientTests.cs
@@ -10,22 +10,37 @@
 using System.Diagnostics;
 using System.Net;
 using System.Net.Sockets;
+using System.Security.Cryptography;
 using System.Threading;
 
 namespace SMBLibrary.Tests.Client
 {
     [TestClass]
     public class SMB2ClientTests
-    {
-        private int m_serverPort;
+    {        
+        // ensure that multiple tests run at the same instant in time receive different port numbers
+        // by incrementing the port number for each test
+        private static readonly int minPort = 1025;
+        private static readonly int maxPort = 65535;
+        private static int m_serverPort = minPort + new Random().Next(maxPort - minPort);
+        
         private TcpListener m_tcpListener;
         private bool m_clientConnected;
+        
+        private static int GetNextPortNumber()
+        {
+            var next = Interlocked.Increment(ref m_serverPort);
+            
+            if (next > maxPort) 
+                next = minPort;
 
+            return next;
+        }
+        
         [TestInitialize]
         public void Initialize()
         {
-            m_serverPort = 1000 + new Random().Next(50000);
-            m_tcpListener = new TcpListener(IPAddress.Loopback, m_serverPort);
+            m_tcpListener = new TcpListener(IPAddress.Loopback, GetNextPortNumber());
             m_tcpListener.Start();
         }
 
diff --git a/SMBLibrary.Tests/NTFileStore/NTDirectoryFileSystemTests.cs b/SMBLibrary.Tests/NTFileStore/NTDirectoryFileSystemTests.cs
index 591572b5..de064818 100644
--- a/SMBLibrary.Tests/NTFileStore/NTDirectoryFileSystemTests.cs
+++ b/SMBLibrary.Tests/NTFileStore/NTDirectoryFileSystemTests.cs
@@ -14,7 +14,7 @@ namespace SMBLibrary.Tests
     [TestClass]
     public class NTDirectoryFileSystemTests : NTFileStoreTests
     {
-        private static readonly string TestDirectoryPath = @"C:\Tests";
+        private static readonly string TestDirectoryPath = Path.Combine(Path.GetTempPath(), "SMBLibraryTests");
 
         static NTDirectoryFileSystemTests()
         {
diff --git a/SMBLibrary/Authentication/NTLM/Helpers/NTLMCryptography.cs b/SMBLibrary/Authentication/NTLM/Helpers/NTLMCryptography.cs
index 4c7e55f2..0e2d8eff 100644
--- a/SMBLibrary/Authentication/NTLM/Helpers/NTLMCryptography.cs
+++ b/SMBLibrary/Authentication/NTLM/Helpers/NTLMCryptography.cs
@@ -284,7 +284,7 @@ public static byte[] ComputeServerSignKey(byte[] exportedSessionKey)
             return ComputeSignKey(exportedSessionKey, false);
         }
 
-        private static byte[] ComputeSignKey(byte[] exportedSessionKey, bool isClient)
+        public static byte[] ComputeSignKey(byte[] exportedSessionKey, bool isClient)
         {
             // https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-nlmp/524cdccb-563e-4793-92b0-7bc321fce096
             string str;
@@ -312,7 +312,7 @@ public static byte[] ComputeServerSealKey(byte[] exportedSessionKey)
             return ComputeSealKey(exportedSessionKey, false);
         }
 
-        private static byte[] ComputeSealKey(byte[] exportedSessionKey, bool isClient)
+        public static byte[] ComputeSealKey(byte[] exportedSessionKey, bool isClient)
         {
             // https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-nlmp/524cdccb-563e-4793-92b0-7bc321fce096
             string str;
diff --git a/SMBLibrary/Authentication/NTLM/IndependentNTLMAuthenticationProvider.cs b/SMBLibrary/Authentication/NTLM/IndependentNTLMAuthenticationProvider.cs
index 2a4cea30..73367f89 100644
--- a/SMBLibrary/Authentication/NTLM/IndependentNTLMAuthenticationProvider.cs
+++ b/SMBLibrary/Authentication/NTLM/IndependentNTLMAuthenticationProvider.cs
@@ -1,4 +1,4 @@
-/* Copyright (C) 2014-2020 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
+/* Copyright (C) 2014-2026 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
  * 
  * You can redistribute this program and/or modify it under the terms of
  * the GNU Lesser Public License as published by the Free Software Foundation,
@@ -78,6 +78,13 @@ public override NTStatus GetChallengeMessage(out object context, byte[] negotiat
             byte[] serverChallenge = GenerateServerChallenge();
             context = new AuthContext(serverChallenge);
 
+            ChallengeMessage challengeMessage = CreateChallengeMessage(negotiateMessage, serverChallenge);
+            challengeMessageBytes = challengeMessage.GetBytes();
+            return NTStatus.SEC_I_CONTINUE_NEEDED;
+        }
+
+        protected virtual ChallengeMessage CreateChallengeMessage(NegotiateMessage negotiateMessage, byte[] serverChallenge)
+        {
             ChallengeMessage challengeMessage = new ChallengeMessage();
             // https://msdn.microsoft.com/en-us/library/cc236691.aspx
             challengeMessage.NegotiateFlags = NegotiateFlags.TargetTypeServer |
@@ -147,8 +154,7 @@ public override NTStatus GetChallengeMessage(out object context, byte[] negotiat
             challengeMessage.ServerChallenge = serverChallenge;
             challengeMessage.TargetInfo = AVPairUtils.GetAVPairSequence(Environment.MachineName, Environment.MachineName);
             challengeMessage.Version = NTLMVersion.Server2003;
-            challengeMessageBytes = challengeMessage.GetBytes();
-            return NTStatus.SEC_I_CONTINUE_NEEDED;
+            return challengeMessage;
         }
 
         public override NTStatus Authenticate(object context, byte[] authenticateMessageBytes)
diff --git a/SMBLibrary/SMBLibrary.csproj b/SMBLibrary/SMBLibrary.csproj
index 138a16e7..6c6655cb 100644
--- a/SMBLibrary/SMBLibrary.csproj
+++ b/SMBLibrary/SMBLibrary.csproj
@@ -3,7 +3,7 @@
   <PropertyGroup>
     <TargetFrameworks>net20;net40;netstandard2.0</TargetFrameworks>
     <AssemblyName>SMBLibrary</AssemblyName>
-    <Version>1.5.6.1</Version>
+    <Version>1.5.6.2</Version>
     <NoWarn>1573;1591</NoWarn>
     <RootNamespace>SMBLibrary</RootNamespace>
     <GeneratePackageOnBuild>false</GeneratePackageOnBuild>