Fix null ref exception in low level client.

Fix UnitTests
Fix Unit Tests.
2026-10-15 00:15:15 +08:00 · 2020-08-05 20:49:11 +02:00 · 2020-07-26 20:07:52 +02:00 · 2020-07-26 12:01:33 +02:00 · 2020-07-25 23:47:29 +02:00 · 2020-07-25 23:34:30 +02:00
293 changed files with 8361 additions and 2818 deletions
@@ -0,0 +1,5 @@
+[*.cs]
+
+
+# CA1031: Do not catch general exception types
+dotnet_diagnostic.CA1031.severity = none
@@ -0,0 +1,46 @@
+---
+name: Bug report
+about: Create a report to help us improve.
+title: ''
+labels: 'bug'
+assignees: ''
+
+---
+
+### Describe the bug
+A clear and concise description of what the bug is.
+
+### Which project is your bug related to?
+<!-- Remove the items which don't apply from the following list -->
+- Client
+- ManagedClient
+- MQTTnet.Server standalone
+- Server
+- Generic
+
+### To Reproduce
+Steps to reproduce the behavior:
+1. Using this version of MQTTnet '...'.
+2. Run this code '....'.
+3. With these arguments '....'.
+4. See error.
+
+### Expected behavior
+A clear and concise description of what you expected to happen.
+
+### Screenshots
+If applicable, add screenshots to help explain your problem.
+
+### Additional context / logging
+Add any other context about the problem here.
+Include debugging or logging information here:
+
+```batch
+\\ Put your logging output here.
+```
+### Code example
+ Please provide full code examples below where possible to make it easier for the developers to check your issues.
+ 
+```csharp
+\\ Put your code here.
+```
@@ -0,0 +1,19 @@
+---
+name: Custom issue template
+about: Do you have a question related to the project? Use this template.
+title: ''
+labels: 'question'
+assignees: ''
+
+---
+
+### Describe your question
+A clear and concise description of what you want to know.
+
+### Which project is your question related to?
+<!-- Remove the items which don't apply from the following list -->
+- Client
+- ManagedClient
+- MQTTnet.Server standalone
+- Server
+- Generic
@@ -0,0 +1,29 @@
+---
+name: Feature request
+about: Suggest an idea for this project.
+title: ''
+labels: 'feature-request'
+assignees: ''
+
+---
+
+### Describe the feature request
+Is your feature request related to a problem? Please describe.
+A clear and concise description of what the problem is. Example. I'm am trying to do [...] but [...]
+
+### Which project is your feature request related to?
+<!-- Remove the items which don't apply from the following list -->
+- Client
+- ManagedClient
+- MQTTnet.Server standalone
+- Server
+- Generic
+
+### Describe the solution you'd like
+A clear and concise description of what you want to happen.
+
+### Describe alternatives you've considered
+A clear and concise description of any alternative solutions or features you've considered.
+
+### Additional context
+Add any other context or screenshots about the feature request here.
@@ -292,3 +292,5 @@ __pycache__/
 *.map

 /Tests/MQTTnet.TestApp.NetCore/RetainedMessages.json
+
+Build/NuGet/
@@ -3,23 +3,26 @@
  <metadata>
    <id>MQTTnet.AspNetCore</id>
    <version>0.0.0</version>
-    <authors>Christian Kratky</authors>
+    <authors>The contributors of MQTTnet</authors>
    <owners>Christian Kratky</owners>
    <license type="file">LICENSE</license>
    <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
    <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
-    <requireLicenseAcceptance>false</requireLicenseAcceptance>
+    <icon>images\Logo_128x128.png</icon>
+    <requireLicenseAcceptance>true</requireLicenseAcceptance>
    <description>This is a support library to integrate MQTTnet into AspNetCore.</description>
    <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2019</copyright>
-    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags>
+    <copyright>Copyright Christian Kratky 2016-2020</copyright>
+    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin Blazor</tags>
    <dependencies>
-      <dependency id="MQTTnet" version="$nugetVersion" />
-
-      <dependency id="Microsoft.AspNetCore.Connections.Abstractions" version="2.1.3" />
-      <dependency id="Microsoft.AspNetCore.Http.Connections" version="1.0.3"  />
-      <dependency id="Microsoft.AspNetCore.WebSockets" version="2.1.1" />
-      <dependency id="Microsoft.Extensions.Hosting.Abstractions" version="2.1.1" />
+      <group targetFramework="netstandard2.0">
+        <dependency id="MQTTnet" version="$nugetVersion" />
+        <dependency id="Microsoft.AspNetCore.Http.Connections" version="1.0.0"  />
+      </group>
+      
+      <group targetFramework="netcoreapp3.1">
+        <dependency id="MQTTnet" version="$nugetVersion" />
+      </group>
    </dependencies>
  </metadata>

@@ -27,7 +30,13 @@
    <!-- License -->
    <file src="..\LICENSE" />

+    <!-- Images -->
+    <file src="..\Images\Logo_128x128.png" target="images\" />
+
    <!-- .NET Standard 2.0 -->
    <file src="..\Source\MQTTnet.AspNetCore\bin\Release\netstandard2.0\MQTTnet.AspNetCore.*" target="lib\netstandard2.0\"/>
+    
+    <!-- .NET Core App 3.1 -->
+    <file src="..\Source\MQTTnet.AspNetCore\bin\Release\netcoreapp3.1\MQTTnet.AspNetCore.*" target="lib\netcoreapp3.1\"/>
  </files>
 </package>
@@ -3,16 +3,17 @@
  <metadata>
    <id>MQTTnet.Extensions.ManagedClient</id>
    <version>0.0.0</version>
-    <authors>Christian Kratky</authors>
+    <authors>The contributors of MQTTnet</authors>
    <owners>Christian Kratky</owners>
    <license type="file">LICENSE</license>
    <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
    <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
-    <requireLicenseAcceptance>false</requireLicenseAcceptance>
+    <icon>images\Logo_128x128.png</icon>
+    <requireLicenseAcceptance>true</requireLicenseAcceptance>
    <description>This is an extension library which provides a managed MQTT client with additional features using MQTTnet.</description>
    <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2019</copyright>
-    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags> 
+    <copyright>Copyright Christian Kratky 2016-2020</copyright>
+    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin Blazor</tags> 
    <dependencies>
      <dependency id="MQTTnet" version="$nugetVersion" />
    </dependencies>
@@ -22,6 +23,9 @@
    <!-- License -->
    <file src="..\LICENSE" />

+    <!-- Images -->
+    <file src="..\Images\Logo_128x128.png" target="images\" />
+
    <!-- .NET Standard 1.3 -->
    <file src="..\Source\MQTTnet.Extensions.ManagedClient\bin\Release\netstandard1.3\MQTTnet.Extensions.ManagedClient.*" target="lib\netstandard1.3\"/>

@@ -3,16 +3,17 @@
  <metadata>
    <id>MQTTnet.Extensions.Rpc</id>
    <version>0.0.0</version>
-    <authors>Christian Kratky</authors>
+    <authors>The contributors of MQTTnet</authors>
    <owners>Christian Kratky</owners>
    <license type="file">LICENSE</license>
    <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
    <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
-    <requireLicenseAcceptance>false</requireLicenseAcceptance>
+    <icon>images\Logo_128x128.png</icon>
+    <requireLicenseAcceptance>true</requireLicenseAcceptance>
    <description>This is an extension library which allows executing synchronous device calls including a response using MQTTnet.</description>
    <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2019</copyright>
-    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags> 
+    <copyright>Copyright Christian Kratky 2016-2020</copyright>
+    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin Blazor</tags> 
    <dependencies>
      <dependency id="MQTTnet" version="$nugetVersion" />
    </dependencies>
@@ -22,6 +23,9 @@
    <!-- License -->
    <file src="..\LICENSE" />

+    <!-- Images -->
+    <file src="..\Images\Logo_128x128.png" target="images\" />
+
    <!-- .NET Standard 1.3 -->
    <file src="..\Source\MQTTnet.Extensions.Rpc\bin\Release\netstandard1.3\MQTTnet.Extensions.Rpc.*" target="lib\netstandard1.3\"/>

@@ -3,18 +3,34 @@
  <metadata>
    <id>MQTTnet.Extensions.WebSocket4Net</id>
    <version>0.0.0</version>
-    <authors>Christian Kratky</authors>
+    <authors>The contributors of MQTTnet</authors>
    <owners>Christian Kratky</owners>
    <license type="file">LICENSE</license>
    <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
    <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
-    <requireLicenseAcceptance>false</requireLicenseAcceptance>
+    <icon>images\Logo_128x128.png</icon>
+    <requireLicenseAcceptance>true</requireLicenseAcceptance>
    <description>This is an extension library which allows using _WebSocket4Net_ as transport for MQTTnet clients.</description>
    <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2019</copyright>
-    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags> 
+    <copyright>Copyright Christian Kratky 2016-2020</copyright>
+    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin Blazor</tags> 
    <dependencies>
-      <dependency id="MQTTnet" version="$nugetVersion" />
+    <group targetFramework="netstandard1.3">
+        <dependency id="MQTTnet" version="$nugetVersion" />
+        <dependency id="WebSocket4Net" version="0.15.2" />
+      </group>
+      <group targetFramework="netstandard2.0">
+        <dependency id="MQTTnet" version="$nugetVersion" />
+        <dependency id="WebSocket4Net" version="0.15.2" />
+      </group>
+      <group targetFramework="netstandard2.1">
+        <dependency id="MQTTnet" version="$nugetVersion" />
+        <dependency id="WebSocket4Net" version="0.15.2" />
+      </group>
+      <group targetFramework="uap10.0">
+        <dependency id="MQTTnet" version="$nugetVersion" />
+        <dependency id="WebSocket4Net" version="0.15.2" />
+      </group>
    </dependencies>
  </metadata>

@@ -22,6 +38,9 @@
    <!-- License -->
    <file src="..\LICENSE" />

+    <!-- Images -->
+    <file src="..\Images\Logo_128x128.png" target="images\" />
+
    <!-- .NET Standard 1.3 -->
    <file src="..\Source\MQTTnet.Extensions.WebSocket4Net\bin\Release\netstandard1.3\MQTTnet.Extensions.WebSocket4Net.*" target="lib\netstandard1.3\"/>

@@ -1,42 +0,0 @@
-<?xml version="1.0"?>
-<package >
-  <metadata>
-    <id>MQTTnet.NETStandard</id>
-    <version>0.0.0</version>
-    <authors>Christian Kratky</authors>
-    <owners>Christian Kratky</owners>
-    <license type="file">LICENSE</license>
-    <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
-    <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
-    <requireLicenseAcceptance>false</requireLicenseAcceptance>
-    <description>This package contains the .NET Standard version of MQTTnet only.</description>
-    <releaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2019</copyright>
-    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags> 
-    <dependencies>
-      <group targetFramework="netstandard1.3">
-        <dependency id="NETStandard.Library" version="1.3.0" />
-        <dependency id="System.Net.Security" version="4.3.2" />
-        <dependency id="System.Net.WebSockets" version="4.3.0" />
-        <dependency id="System.Net.WebSockets.Client" version="4.3.2" />      
-      </group>
-      <group targetFramework="netstandard2.0">
-        <dependency id="NETStandard.Library" version="2.0.0" />
-        <dependency id="System.Net.Security" version="4.3.2" />
-        <dependency id="System.Net.WebSockets" version="4.3.0" />
-        <dependency id="System.Net.WebSockets.Client" version="4.3.2" />
-      </group>
-    </dependencies>
-  </metadata>
-
-  <files>
-    <!-- License -->
-    <file src="..\LICENSE" />
-
-    <!-- .NET Standard 1.3 -->
-    <file src="..\Source\MQTTnet\bin\Release\netstandard1.3\MQTTnet.*" target="lib\netstandard1.3\"/>
-
-    <!-- .NET Standard 2.0 -->
-    <file src="..\Source\MQTTnet\bin\Release\netstandard2.0\MQTTnet.*" target="lib\netstandard2.0\"/>
-  </files>
-</package>
@@ -3,33 +3,28 @@
  <metadata>
    <id>MQTTnet</id>
    <version>0.0.0</version>
-    <authors>Christian Kratky</authors>
+    <authors>The contributors of MQTTnet</authors>
    <owners>Christian Kratky</owners>
    <license type="file">LICENSE</license>
    <projectUrl>https://github.com/chkr1011/MQTTnet</projectUrl>
    <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
-    <requireLicenseAcceptance>false</requireLicenseAcceptance>
+    <icon>images\Logo_128x128.png</icon>
+    <requireLicenseAcceptance>true</requireLicenseAcceptance>
    <description>MQTTnet is a high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker) and supports v3.1.0, v3.1.1 and v5.0.0 of the MQTT protocol.</description>
    <releaseNotes>
-* [Core] Fixed issues in MQTTv5 message encoding and decoding.
-* [Core] Added extension method to allow usage of _WebSocket4Net_ in clients to fix issues with AWS and Xamarin.
-* [Core] Fixed usage of wrong data type for passwords (string -> byte[]).
-* [Core] Fixed an _ObjectDisposedException_ when sending data using a WebSocket channel.
-* [Core] Performance optimizations.
-* [Client] Added support for extended authentication exchange.
-* [Client] Exposed MQTTv5 CONNACK values to client.
-* [Client] Added _MqttClientSubscribeOptionsBuilder_.
-* [Client] The disconnected handler is now executed in a new task to prevent deadlocks when reconnecting etc. (thanks to @lizziebeans).
-* [Client] Converted option _DualMode_ into nullable boolean to preserve original value and avoid exceptions in IPv4 only networks (thanks to @lavaflo).
-* [Server] Exposed _ClientCertificateRequired_ and _CheckCertificateRevocation_ at TLS options.
-* [Server] Exposed client certificate at client connection validator.
-* [Server] The subscription interceptor now supports altering the entire topic filter.
-* [Server] Exposed more properties to the connection validator context.
-* [MQTTnet.Server] Added authentication support via Python script file.
-* [MQTTnet.Server] Migrated the result of connection validations to _ReasonCode_ (MQTTv5) instead of _ReturnCode_ (MQTTv3 only) (BREAKING CHANGE!).
+* [LowLevelClient] Fixed a null reference exception when connecting to a not existing server (thanks to @SGStino).      
+* [RcpClient] Adjusted some namespaces (BREAKING CHANGE!).
+* [AspNetCore] Adjusted some namespaces (BREAKING CHANGE!).
+* [Server] Adjusted some namespaces (BREAKING CHANGE!).
+* [Server] Added state checks (throw if not started etc.) for most server APIs.
+* [Server] Exposed real X509Certificate2 (instead byte array) to TLS options (thanks to @borigas).
+* [Server] Fixed memory leak with TCP sockets (MqttServer is now Disposable!) (BREAKING CHANGE!).
+* [Core] Fixed a null reference exception in the MqttTcpChannel with WriteAsync and ReadAsync.
+* [Core] Added server interceptor for undelivered messages (thanks to @cshark-inator).
+* [nuget] Added support for SourceLink (thanks to @JTOne123).
    </releaseNotes>
-    <copyright>Copyright Christian Kratky 2016-2019</copyright>
-    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags> 
+    <copyright>Copyright Christian Kratky 2016-2020</copyright>
+    <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin Blazor</tags> 
    <dependencies>
      <group targetFramework="netstandard1.3">
        <dependency id="NETStandard.Library" version="1.3.0" />
@@ -43,8 +38,14 @@
        <dependency id="System.Net.WebSockets" version="4.3.0" />
        <dependency id="System.Net.WebSockets.Client" version="4.3.2" />
      </group>
+      <group targetFramework="netstandard2.1">
+        <dependency id="NETStandard.Library" version="2.0.0" />
+        <dependency id="System.Net.Security" version="4.3.2" />
+        <dependency id="System.Net.WebSockets" version="4.3.0" />
+        <dependency id="System.Net.WebSockets.Client" version="4.3.2" />
+      </group>
      <group targetFramework="uap10.0">
-        <dependency id="Microsoft.NETCore.UniversalWindowsPlatform" version="6.2.8" />
+        <dependency id="Microsoft.NETCore.UniversalWindowsPlatform" version="6.2.10" />
      </group>
    </dependencies>
  </metadata>
@@ -53,12 +54,18 @@
    <!-- License -->
    <file src="..\LICENSE" />

+    <!-- Images -->
+    <file src="..\Images\Logo_128x128.png" target="images\" />
+
    <!-- .NET Standard 1.3 -->
    <file src="..\Source\MQTTnet\bin\Release\netstandard1.3\MQTTnet.*" target="lib\netstandard1.3\"/>
    
    <!-- .NET Standard 2.0 -->
    <file src="..\Source\MQTTnet\bin\Release\netstandard2.0\MQTTnet.*" target="lib\netstandard2.0\"/>

+    <!-- .NET Standard 2.1 -->
+    <file src="..\Source\MQTTnet\bin\Release\netstandard2.1\MQTTnet.*" target="lib\netstandard2.1\"/>
+
    <!-- Universal Windows -->
    <file src="..\Source\MQTTnet\bin\Release\uap10.0\MQTTnet.*" target="lib\uap10.0\"/>

@@ -70,4 +77,4 @@

    <!-- Everything above .NET Framework 4.6.1 will use the binaries from 4.6.1. -->
  </files>
-</package>
+</package>
@@ -12,21 +12,35 @@ Write-Host "Nuget version    = $nugetVersion"
 Write-Host "MSBuild path     = $msbuild"
 Write-Host

+Invoke-WebRequest -Uri "https://dist.nuget.org/win-x86-commandline/latest/nuget.exe" -OutFile "nuget.exe"
+
+.\nuget.exe restore ..\MQTTnet.sln
+
+# Build and execute tests
+&$msbuild ..\Tests\MQTTnet.Core.Tests\MQTTnet.Tests.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netcoreapp3.1" /verbosity:m
+&$msbuild ..\Tests\MQTTnet.AspNetCore.Tests\MQTTnet.AspNetCore.Tests.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netcoreapp3.1" /verbosity:m
+
+vstest.console.exe ..\Tests\MQTTnet.Core.Tests\bin\Release\netcoreapp3.1\MQTTnet.Tests.dll
+vstest.console.exe ..\Tests\MQTTnet.AspNetCore.Tests\bin\Release\netcoreapp3.1\MQTTnet.AspNetCore.Tests.dll
+
 # Build the core library
 &$msbuild ..\Source\MQTTnet\MQTTnet.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net452" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet\MQTTnet.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net461" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet\MQTTnet.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard1.3" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet\MQTTnet.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
+&$msbuild ..\Source\MQTTnet\MQTTnet.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.1" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet\MQTTnet.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="uap10.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"

 # Build the ASP.NET Core 2.0 extension
 &$msbuild ..\Source\MQTTnet.AspNetCore\MQTTnet.AspNetCore.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
+&$msbuild ..\Source\MQTTnet.AspNetCore\MQTTnet.AspNetCore.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netcoreapp3.1" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"

 # Build the RPC extension
 &$msbuild ..\Source\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net452" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net461" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard1.3" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
+&$msbuild ..\Source\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.1" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="uap10.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"

 # Build the Managed Client extension
@@ -34,6 +48,7 @@ Write-Host
 &$msbuild ..\Source\MQTTnet.Extensions.ManagedClient\MQTTnet.Extensions.ManagedClient.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net461" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet.Extensions.ManagedClient\MQTTnet.Extensions.ManagedClient.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard1.3" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet.Extensions.ManagedClient\MQTTnet.Extensions.ManagedClient.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
+&$msbuild ..\Source\MQTTnet.Extensions.ManagedClient\MQTTnet.Extensions.ManagedClient.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.1" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet.Extensions.ManagedClient\MQTTnet.Extensions.ManagedClient.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="uap10.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"

 # Build the WebSocket4Net extension
@@ -41,58 +56,11 @@ Write-Host
 &$msbuild ..\Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="net461" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard1.3" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
+&$msbuild ..\Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="netstandard2.1" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"
 &$msbuild ..\Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj /t:Build /p:Configuration="Release" /p:TargetFramework="uap10.0" /p:FileVersion=$assemblyVersion /p:AssemblyVersion=$assemblyVersion /verbosity:m /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=".\..\..\Build\codeSigningKey.pfx"

-####################################################################
-
-# Build MQTTnet.Server Portable
-&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion
-
-$source = "..\Source\MQTTnet.Server\bin\Release\netcoreapp2.2\publish"
-$destination = "..\Source\MQTTnet.Server\bin\MQTTnet.Server-Portable-v$nugetVersion.zip"
-If(Test-path $destination) {Remove-item $destination}
- Add-Type -assembly "system.io.compression.filesystem"
-[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
-
-####################################################################
-
-# Build MQTTnet.Server Linux-x64
-&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion --self-contained --runtime linux-x64 
-
-$source = "..\Source\MQTTnet.Server\bin\Release\netcoreapp2.2\linux-x64\publish"
-$destination = "..\Source\MQTTnet.Server\bin\MQTTnet.Server-Linux-x64-v$nugetVersion.zip"
-If(Test-path $destination) {Remove-item $destination}
- Add-Type -assembly "system.io.compression.filesystem"
-[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
-
-####################################################################
-
-# Build MQTTnet.Server Linux-ARM
-&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion --self-contained --runtime linux-arm 
-
-$source = "..\Source\MQTTnet.Server\bin\Release\netcoreapp2.2\linux-ARM\publish"
-$destination = "..\Source\MQTTnet.Server\bin\MQTTnet.Server-Linux-ARM-v$nugetVersion.zip"
-If(Test-path $destination) {Remove-item $destination}
- Add-Type -assembly "system.io.compression.filesystem"
-[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
-
-####################################################################
-
-# Build MQTTnet.Server Windows-x64
-&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion --self-contained --runtime win-x64
-
-$source = "..\Source\MQTTnet.Server\bin\Release\netcoreapp2.2\win-x64\publish"
-$destination = "..\Source\MQTTnet.Server\bin\MQTTnet.Server-Windows-x64-v$nugetVersion.zip"
-If(Test-path $destination) {Remove-item $destination}
- Add-Type -assembly "system.io.compression.filesystem"
-[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
-
-####################################################################
-
 # Create NuGet packages.

-Invoke-WebRequest -Uri "https://dist.nuget.org/win-x86-commandline/latest/nuget.exe" -OutFile "nuget.exe"
-
 Remove-Item .\NuGet -Force -Recurse -ErrorAction SilentlyContinue

 Copy-Item MQTTnet.AspNetCore.nuspec -Destination MQTTnet.AspNetCore.nuspec.old -Force
@@ -105,16 +73,61 @@ Copy-Item MQTTnet.Extensions.WebSocket4Net.nuspec -Destination MQTTnet.Extension
 (Get-Content MQTTnet.Extensions.WebSocket4Net.nuspec) -replace '\$nugetVersion', $nugetVersion | Set-Content MQTTnet.Extensions.WebSocket4Net.nuspec

 New-Item -ItemType Directory -Force -Path .\NuGet
-.\nuget.exe pack MQTTnet.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
-.\nuget.exe pack MQTTnet.NETStandard.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
-.\nuget.exe pack MQTTnet.AspNetCore.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
-.\nuget.exe pack MQTTnet.Extensions.Rpc.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
-.\nuget.exe pack MQTTnet.Extensions.ManagedClient.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
-.\nuget.exe pack MQTTnet.Extensions.WebSocket4Net.nuspec -Verbosity detailed -Symbols -OutputDir "NuGet" -Version $nugetVersion
+.\nuget.exe pack MQTTnet.nuspec -Verbosity detailed -Symbols -SymbolPackageFormat snupkg -OutputDir "NuGet" -Version $nugetVersion
+.\nuget.exe pack MQTTnet.AspNetCore.nuspec -Verbosity detailed -Symbols -SymbolPackageFormat snupkg -OutputDir "NuGet" -Version $nugetVersion
+.\nuget.exe pack MQTTnet.Extensions.Rpc.nuspec -Verbosity detailed -Symbols -SymbolPackageFormat snupkg -OutputDir "NuGet" -Version $nugetVersion
+.\nuget.exe pack MQTTnet.Extensions.ManagedClient.nuspec -Verbosity detailed -Symbols -SymbolPackageFormat snupkg -OutputDir "NuGet" -Version $nugetVersion
+.\nuget.exe pack MQTTnet.Extensions.WebSocket4Net.nuspec -Verbosity detailed -Symbols -SymbolPackageFormat snupkg -OutputDir "NuGet" -Version $nugetVersion

 Move-Item MQTTnet.AspNetCore.nuspec.old -Destination MQTTnet.AspNetCore.nuspec -Force
 Move-Item MQTTnet.Extensions.Rpc.nuspec.old -Destination MQTTnet.Extensions.Rpc.nuspec -Force
 Move-Item MQTTnet.Extensions.ManagedClient.nuspec.old -Destination MQTTnet.Extensions.ManagedClient.nuspec -Force
 Move-Item MQTTnet.Extensions.WebSocket4Net.nuspec.old -Destination MQTTnet.Extensions.WebSocket4Net.nuspec -Force

-Remove-Item "nuget.exe" -Force -Recurse -ErrorAction SilentlyContinue
+Remove-Item "nuget.exe" -Force -Recurse -ErrorAction SilentlyContinue
+
+####################################################################
+
+# Build MQTTnet.Server Portable
+&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion
+
+$source = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\Release\netcoreapp3.1\publish"
+$destination = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\MQTTnet.Server-Portable-v$nugetVersion.zip"
+If(Test-path $destination) {Remove-item $destination}
+ Add-Type -assembly "system.io.compression.filesystem"
+[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
+
+####################################################################
+
+# Build MQTTnet.Server Linux-x64
+&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion --self-contained --runtime linux-x64 
+
+$source = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\Release\netcoreapp3.1\linux-x64\publish"
+$destination = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\MQTTnet.Server-Linux-x64-v$nugetVersion.zip"
+If(Test-path $destination) {Remove-item $destination}
+ Add-Type -assembly "system.io.compression.filesystem"
+[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
+
+####################################################################
+
+# Build MQTTnet.Server Linux-ARM
+&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion --self-contained --runtime linux-arm 
+
+$source = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\Release\netcoreapp3.1\linux-ARM\publish"
+$destination = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\MQTTnet.Server-Linux-ARM-v$nugetVersion.zip"
+If(Test-path $destination) {Remove-item $destination}
+ Add-Type -assembly "system.io.compression.filesystem"
+[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
+
+####################################################################
+
+# Build MQTTnet.Server Windows-x64
+&dotnet publish ..\Source\MQTTnet.Server\MQTTnet.Server.csproj --configuration Release /p:FileVersion=$assemblyVersion /p:Version=$nugetVersion --self-contained --runtime win-x64
+
+$source = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\Release\netcoreapp3.1\win-x64\publish"
+$destination = (Convert-Path .) + "\..\Source\MQTTnet.Server\bin\MQTTnet.Server-Windows-x64-v$nugetVersion.zip"
+If(Test-path $destination) {Remove-item $destination}
+ Add-Type -assembly "system.io.compression.filesystem"
+[io.compression.zipfile]::CreateFromDirectory($source, $destination) 
+
+####################################################################
@@ -7,7 +7,7 @@ foreach ($file in $files)
 {
 	Write-Host "Uploading: " $file

-	.\nuget.exe push $file.Fullname $apiKey -NoSymbols -Source https://api.nuget.org/v3/index.json
+	.\nuget.exe push $file.Fullname $apiKey -Source https://api.nuget.org/v3/index.json
 }

 Remove-Item "nuget.exe" -Force -Recurse -ErrorAction SilentlyContinue
@@ -1,9 +1,9 @@
 # Import codeSigningKey.pfx
 In order to import the key for code signing on a new developer machine use the following command within the VS developer command line:

-> sn –i codeSigningKey.pfx VS_KEY_EFCA4C5B6DFD4B4F
+sn –i .\codeSigningKey.pfx VS_KEY_62CA73019ED23333

 The container name may be different.

 # Check if the assembly has a strong name
-> sn -vf MQTTnet.dll
+sn -vf MQTTnet.dll
@@ -0,0 +1,239 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   width="210mm"
+   height="297mm"
+   viewBox="0 0 210 297"
+   version="1.1"
+   id="svg8"
+   inkscape:version="0.92.4 (5da689c313, 2019-01-14)"
+   sodipodi:docname="MQTT.svg">
+  <defs
+     id="defs2">
+    <filter
+       inkscape:label="Blur Double"
+       inkscape:menu="Blurs"
+       inkscape:menu-tooltip="Overlays two copies with different blur amounts and modifiable blend and composite"
+       style="color-interpolation-filters:sRGB;"
+       id="filter3801">
+      <feGaussianBlur
+         stdDeviation="5"
+         result="fbSourceGraphic"
+         id="feGaussianBlur3793" />
+      <feGaussianBlur
+         stdDeviation="0.01"
+         in="SourceGraphic"
+         result="result1"
+         id="feGaussianBlur3795" />
+      <feComposite
+         in2="result1"
+         operator="arithmetic"
+         in="fbSourceGraphic"
+         k2="0.5"
+         k3="0.5"
+         result="result2"
+         id="feComposite3797" />
+      <feBlend
+         in2="fbSourceGraphic"
+         mode="normal"
+         result="result3"
+         id="feBlend3799" />
+    </filter>
+  </defs>
+  <sodipodi:namedview
+     id="base"
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1.0"
+     inkscape:pageopacity="0.0"
+     inkscape:pageshadow="2"
+     inkscape:zoom="0.24748737"
+     inkscape:cx="955.72999"
+     inkscape:cy="295.38958"
+     inkscape:document-units="mm"
+     inkscape:current-layer="layer1"
+     showgrid="false"
+     inkscape:window-width="3840"
+     inkscape:window-height="2066"
+     inkscape:window-x="2989"
+     inkscape:window-y="-11"
+     inkscape:window-maximized="1" />
+  <metadata
+     id="metadata5">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title />
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <g
+     inkscape:label="Layer 1"
+     inkscape:groupmode="layer"
+     id="layer1">
+    <rect
+       ry="50"
+       rx="50"
+       style="fill:#000000;stroke-width:0.26458332;filter:url(#filter3801)"
+       y="92.501205"
+       x="56.367012"
+       height="512"
+       width="512"
+       id="rect3791"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001" />
+    <rect
+       id="rect3713"
+       width="512"
+       height="512"
+       x="53.721176"
+       y="88.797035"
+       style="fill:#aa0000;stroke-width:0.26458332"
+       rx="50"
+       ry="50"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001" />
+    <rect
+       style="fill:#ce0000;fill-opacity:0.60591131;stroke-width:0.28100395"
+       id="rect3806"
+       width="143.25298"
+       height="9.0714283"
+       x="270.81995"
+       y="554.02386"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001" />
+    <path
+       inkscape:connector-curvature="0"
+       id="path4638"
+       d="m 494.14104,142.00092 -5.35736,41.28822 67.77684,374.38977 a 263.46279,229.17651 36.835702 0 1 4.98278,-0.4605 263.46279,229.17651 36.835702 0 1 7.77403,0.0471 z"
+       style="fill:#ce0000;fill-opacity:0.60591131;stroke-width:0.59952348"
+       inkscape:transform-center-x="-28.818481"
+       inkscape:transform-center-y="146.97441"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001" />
+    <path
+       style="fill:#d40000;stroke-width:1.76103246"
+       d="m 2138.1582,1411.377 a 995.76488,866.17897 0 0 0 -842.3984,854.3418 995.76488,866.17897 0 0 0 0.2988,5.0097 h 653.123 c 104.693,0 188.9766,-84.2836 188.9766,-188.9765 z"
+       transform="scale(0.26458333)"
+       id="path3715-5-8"
+       inkscape:connector-curvature="0"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001" />
+    <ellipse
+       style="fill:#d40000;stroke-width:0.06901014"
+       id="path3715-5"
+       cx="492.58557"
+       cy="170.58017"
+       rx="39.021355"
+       ry="33.94323"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001" />
+    <path
+       style="fill:#ce0000;fill-opacity:0.60591131;stroke-width:2.26591563"
+       d="M 464.66602,532.89453 542.01562,669.92969 1595.373,1648.873 a 995.76487,866.17896 0 0 1 14.0293,-12.6835 995.76487,866.17896 0 0 1 23.6231,-17.4727 z"
+       id="rect3806-2"
+       inkscape:connector-curvature="0"
+       transform="scale(0.26458333)"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001" />
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:10.58333302px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       x="102.34985"
+       y="320.75201"
+       id="text3774"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001"><tspan
+         sodipodi:role="line"
+         id="tspan3772"
+         x="102.34985"
+         y="320.75201"
+         style="font-size:141.1111145px;fill:#ffffff;stroke-width:0.26458332">MQTT</tspan></text>
+    <ellipse
+       ry="33.94323"
+       rx="39.021355"
+       cy="148.56271"
+       cx="124.47787"
+       id="ellipse3768"
+       style="fill:#d40000;stroke-width:0.06901014"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001" />
+    <ellipse
+       style="fill:#d40000;stroke-width:0.06901014"
+       id="ellipse3770"
+       cx="234.9953"
+       cy="556.91571"
+       rx="39.021355"
+       ry="33.94323"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001" />
+    <text
+       id="text3778"
+       y="474.73837"
+       x="194.57605"
+       style="font-style:normal;font-weight:normal;font-size:10.58333302px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       xml:space="preserve"
+       inkscape:export-xdpi="2.6500001"
+       inkscape:export-ydpi="2.6500001"><tspan
+         style="font-size:141.1111145px;fill:#ffffff;stroke-width:0.26458332"
+         y="474.73837"
+         x="194.57605"
+         id="tspan3776"
+         sodipodi:role="line">net</tspan></text>
+    <rect
+       ry="50"
+       rx="50"
+       style="fill:#aa0000;stroke-width:0.26458332"
+       y="97.349655"
+       x="-672.18286"
+       height="512"
+       width="512"
+       id="rect4642"
+       inkscape:export-xdpi="6.3499999"
+       inkscape:export-ydpi="6.3499999" />
+    <path
+       inkscape:connector-curvature="0"
+       id="path4648"
+       d="m -160.18302,381.97945 a 263.46279,229.17652 0 0 0 -222.88457,226.0446 263.46279,229.17652 0 0 0 0.0791,1.32549 h 172.80546 c 27.70002,0 50.00005,-22.30004 50.00005,-50.00004 z"
+       style="fill:#d40000;stroke-width:0.46593982"
+       inkscape:export-xdpi="6.3499999"
+       inkscape:export-ydpi="6.3499999" />
+    <text
+       id="text4656"
+       y="329.30466"
+       x="-639.42944"
+       style="font-style:normal;font-weight:normal;font-size:10.58333302px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       xml:space="preserve"
+       inkscape:export-xdpi="6.3499999"
+       inkscape:export-ydpi="6.3499999"><tspan
+         style="font-weight:bold;font-size:141.1111145px;fill:#ffffff;stroke-width:0.26458332"
+         y="329.30466"
+         x="-639.42944"
+         id="tspan4654"
+         sodipodi:role="line">MQTT</tspan></text>
+    <text
+       xml:space="preserve"
+       style="font-style:normal;font-weight:normal;font-size:10.58333302px;line-height:1.25;font-family:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       x="-550.90747"
+       y="482.23267"
+       id="text4664"
+       inkscape:export-xdpi="6.3499999"
+       inkscape:export-ydpi="6.3499999"><tspan
+         sodipodi:role="line"
+         id="tspan4662"
+         x="-550.90747"
+         y="482.23267"
+         style="font-weight:bold;font-size:141.1111145px;fill:#ffffff;stroke-width:0.26458332">net</tspan></text>
+  </g>
+</svg>
@@ -1,6 +1,6 @@
 MIT License

-MQTTnet Copyright (c) 2016-2019 Christian Kratky
+Copyright (c) 2016-2019 Christian Kratky

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -20,7 +20,6 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Build", "Build", "{67C28AC1
 		Build\MQTTnet.Extensions.ManagedClient.nuspec = Build\MQTTnet.Extensions.ManagedClient.nuspec
 		Build\MQTTnet.Extensions.Rpc.nuspec = Build\MQTTnet.Extensions.Rpc.nuspec
 		Build\MQTTnet.Extensions.WebSocket4Net.nuspec = Build\MQTTnet.Extensions.WebSocket4Net.nuspec
-		Build\MQTTnet.NETStandard.nuspec = Build\MQTTnet.NETStandard.nuspec
 		Build\MQTTnet.nuspec = Build\MQTTnet.nuspec
 		Build\upload.ps1 = Build\upload.ps1
 	EndProjectSection
@@ -28,6 +27,7 @@ EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{B3F60ECB-45BA-4C66-8903-8BB89CA67998}"
 	ProjectSection(SolutionItems) = preProject
 		.bettercodehub.yml = .bettercodehub.yml
+		.editorconfig = .editorconfig
 		appveyor.yml = appveyor.yml
 		LICENSE = LICENSE
 		README.md = README.md
@@ -53,6 +53,16 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.Server", "Source\MQ
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.Extensions.WebSocket4Net", "Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj", "{2BD01D53-4CA5-4142-BE8D-313876395E3E}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Apps", "Apps", "{A56E3128-1639-4F31-873A-325E14BB6295}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Blazor", "Blazor", "{61B165A0-5AA8-4E04-A53D-A22A84AA6EB7}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.Test.BlazorApp.Server", "Tests\MQTTnet.Test.BlazorApp\Server\MQTTnet.Test.BlazorApp.Server.csproj", "{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.Test.BlazorApp.Client", "Tests\MQTTnet.Test.BlazorApp\Client\MQTTnet.Test.BlazorApp.Client.csproj", "{D260D63D-7902-4C55-9665-84C5CACBBB24}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.Test.BlazorApp.Shared", "Tests\MQTTnet.Test.BlazorApp\Shared\MQTTnet.Test.BlazorApp.Shared.csproj", "{DDB069BA-6E1A-48C7-B374-5D903B553CAD}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -264,13 +274,61 @@ Global
 		{2BD01D53-4CA5-4142-BE8D-313876395E3E}.Release|x64.Build.0 = Release|Any CPU
 		{2BD01D53-4CA5-4142-BE8D-313876395E3E}.Release|x86.ActiveCfg = Release|Any CPU
 		{2BD01D53-4CA5-4142-BE8D-313876395E3E}.Release|x86.Build.0 = Release|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Debug|ARM.ActiveCfg = Debug|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Debug|ARM.Build.0 = Debug|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Debug|x64.Build.0 = Debug|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Debug|x86.Build.0 = Debug|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Release|ARM.ActiveCfg = Release|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Release|ARM.Build.0 = Release|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Release|x64.ActiveCfg = Release|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Release|x64.Build.0 = Release|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Release|x86.ActiveCfg = Release|Any CPU
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F}.Release|x86.Build.0 = Release|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Debug|ARM.ActiveCfg = Debug|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Debug|ARM.Build.0 = Debug|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Debug|x64.Build.0 = Debug|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Debug|x86.Build.0 = Debug|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Release|ARM.ActiveCfg = Release|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Release|ARM.Build.0 = Release|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Release|x64.ActiveCfg = Release|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Release|x64.Build.0 = Release|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Release|x86.ActiveCfg = Release|Any CPU
+		{D260D63D-7902-4C55-9665-84C5CACBBB24}.Release|x86.Build.0 = Release|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Debug|ARM.ActiveCfg = Debug|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Debug|ARM.Build.0 = Debug|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Debug|x64.Build.0 = Debug|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Debug|x86.Build.0 = Debug|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Release|Any CPU.Build.0 = Release|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Release|ARM.ActiveCfg = Release|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Release|ARM.Build.0 = Release|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Release|x64.ActiveCfg = Release|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Release|x64.Build.0 = Release|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Release|x86.ActiveCfg = Release|Any CPU
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{A7FF0C91-25DE-4BA6-B39E-F54E8DADF1CC} = {9248C2E1-B9D6-40BF-81EC-86004D7765B4}
-		{FF1F72D6-9524-4422-9497-3CC0002216ED} = {9248C2E1-B9D6-40BF-81EC-86004D7765B4}
+		{FF1F72D6-9524-4422-9497-3CC0002216ED} = {A56E3128-1639-4F31-873A-325E14BB6295}
 		{3587E506-55A2-4EB3-99C7-DC01E42D25D2} = {32A630A7-2598-41D7-B625-204CD906F5FB}
 		{3D283AAD-AAA8-4339-8394-52F80B6304DB} = {9248C2E1-B9D6-40BF-81EC-86004D7765B4}
 		{C6FF8AEA-0855-41EC-A1F3-AC262225BAB9} = {9248C2E1-B9D6-40BF-81EC-86004D7765B4}
@@ -279,8 +337,12 @@ Global
 		{998D04DD-7CB0-45F5-A393-E2495C16399E} = {9248C2E1-B9D6-40BF-81EC-86004D7765B4}
 		{C400533A-8EBA-4F0B-BF4D-295C3708604B} = {12816BCC-AF9E-44A9-9AE5-C246AF2A0587}
 		{61B62223-F5D0-48E4-BBD6-2CBA9353CB5E} = {9248C2E1-B9D6-40BF-81EC-86004D7765B4}
-		{5699FB8C-838C-4AB0-80A5-9CA809F9B65B} = {32A630A7-2598-41D7-B625-204CD906F5FB}
+		{5699FB8C-838C-4AB0-80A5-9CA809F9B65B} = {A56E3128-1639-4F31-873A-325E14BB6295}
 		{2BD01D53-4CA5-4142-BE8D-313876395E3E} = {12816BCC-AF9E-44A9-9AE5-C246AF2A0587}
+		{61B165A0-5AA8-4E04-A53D-A22A84AA6EB7} = {9248C2E1-B9D6-40BF-81EC-86004D7765B4}
+		{A9662AF3-3520-4BF8-9DFF-C55C0C33D08F} = {61B165A0-5AA8-4E04-A53D-A22A84AA6EB7}
+		{D260D63D-7902-4C55-9665-84C5CACBBB24} = {61B165A0-5AA8-4E04-A53D-A22A84AA6EB7}
+		{DDB069BA-6E1A-48C7-B374-5D903B553CAD} = {61B165A0-5AA8-4E04-A53D-A22A84AA6EB7}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {07536672-5CBC-4BE3-ACE0-708A431A7894}
@@ -1,5 +1,5 @@
 <p align="center">
-<img src="https://github.com/chkr1011/MQTTnet/blob/master/Images/Logo_128x128.png?raw=true" width="128">
+<img src="https://github.com/chkr1011/MQTTnet/blob/master/Images/icon_det_256.png?raw=true" width="196">
 <br/>
 <br/>
 </p>
@@ -7,8 +7,8 @@
 [![NuGet Badge](https://buildstats.info/nuget/MQTTnet)](https://www.nuget.org/packages/MQTTnet)
 [![Build status](https://ci.appveyor.com/api/projects/status/ycit86voxfevm2aa/branch/master?svg=true)](https://ci.appveyor.com/project/chkr1011/mqttnet)
 [![BCH compliance](https://bettercodehub.com/edge/badge/chkr1011/MQTTnet?branch=master)](https://bettercodehub.com/)
-[![OpenCollective](https://opencollective.com/mqttnet/backers/badge.svg)](https://opencollective.com/mqttnet) 
-[![OpenCollective](https://opencollective.com/mqttnet/sponsors/badge.svg)](https://opencollective.com/mqttnet) [![Join the chat at https://gitter.im/MQTTnet/community](https://badges.gitter.im/MQTTnet/community.svg)](https://gitter.im/MQTTnet/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![Join the chat at https://gitter.im/MQTTnet/community](https://badges.gitter.im/MQTTnet/community.svg)](https://gitter.im/MQTTnet/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://raw.githubusercontent.com/chkr1011/MQTTnet/master/LICENSE)

 # MQTTnet

@@ -26,7 +26,7 @@ MQTTnet is a high performance .NET library for MQTT based communication. It prov
 * Uniform API across all supported versions of the MQTT protocol
 * Interfaces included for mocking and testing
 * Access to internal trace messages
-* Unit tested (~210 tests)
+* Unit tested (~250 tests)
 * No external dependencies

 \* Tested on local machine (Intel i7 8700K) with MQTTnet client and server running in the same process using the TCP channel. The app for verification is part of this repository and stored in _/Tests/MQTTnet.TestApp.NetCore_.
@@ -34,7 +34,7 @@ MQTTnet is a high performance .NET library for MQTT based communication. It prov
 ### Client

 * Communication via TCP (+TLS) or WS (WebSocket) supported
-* Included core _MqttClient_ with low level functionality
+* Included core _LowLevelMqttClient_ with low level functionality
 * Also included _ManagedMqttClient_ which maintains the connection and subscriptions automatically. Also application messages are queued and re-scheduled for higher QoS levels automatically.
 * Rx support (via another project)
 * Compatible with Microsoft Azure IoT Hub
@@ -72,6 +72,7 @@ _MQTTnet Server_ is a standalone cross platform MQTT server (like mosquitto) bas
 * Universal Windows Platform (UWP) 10.0.10240+ (x86, x64, ARM, AnyCPU, Windows 10 IoT Core)
 * Xamarin.Android 7.5+
 * Xamarin.iOS 10.14+
+* Blazor WebAssembly 3.2.0

 ## Supported MQTT versions

@@ -92,8 +93,6 @@ Please find examples and the documentation at the Wiki of this repository (<http
 If you want to contribute to this project just create a pull request. But only pull requests which are matching the code style of this library will be accepted. Before creating a pull request please have a look at the library to get an overview of the required style.
 Also additions and updates in the Wiki are welcome.

-**This project, like all projects requires time and money.  If you feel compelled to support the development team, you can do so through Open Collective (https://opencollective.com/mqttnet)**.
-
 ## References

 This library is used in the following projects:
@@ -104,13 +103,15 @@ This library is used in the following projects:
 * MQTT Tester (MQTT client test app for [Android](https://play.google.com/store/apps/details?id=com.liveowl.mqtttester) and [iOS](https://itunes.apple.com/us/app/mqtt-tester/id1278621826?mt=8))
 * Wirehome.Core (Open Source Home Automation system for .NET Core, <https://github.com/chkr1011/Wirehome.Core>)

+Further projects using this project can be found under https://github.com/chkr1011/MQTTnet/network/dependents.
+
 If you use this library and want to see your project here please create a pull request.

 ## License

 MIT License

-MQTTnet Copyright (c) 2016-2019 Christian Kratky
+MQTTnet Copyright (c) 2016-2020 Christian Kratky

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -1,17 +1,15 @@
-using System;
-using System.Net;
-using MQTTnet.Adapter;
+using MQTTnet.Adapter;
 using MQTTnet.AspNetCore.Client.Tcp;
-using MQTTnet.Client;
 using MQTTnet.Client.Options;
-using MQTTnet.Diagnostics;
 using MQTTnet.Formatter;
+using System;
+using System.Net;

 namespace MQTTnet.AspNetCore.Client
 {
    public class MqttClientConnectionContextFactory : IMqttClientAdapterFactory
    {
-        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetChildLogger logger)
+        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options)
        {
            if (options == null) throw new ArgumentNullException(nameof(options));

@@ -1,13 +1,13 @@
-using System;
+using Microsoft.AspNetCore.Connections;
+using Microsoft.AspNetCore.Http.Features;
+using MQTTnet.Exceptions;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.IO.Pipelines;
 using System.Net;
 using System.Net.Sockets;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Connections;
-using Microsoft.AspNetCore.Http.Features;
-using MQTTnet.Exceptions;

 namespace MQTTnet.AspNetCore.Client.Tcp
 {
@@ -40,8 +40,11 @@ namespace MQTTnet.AspNetCore.Client.Tcp
            _sender = new SocketSender(_socket, PipeScheduler.ThreadPool);
            _receiver = new SocketReceiver(_socket, PipeScheduler.ThreadPool);
        }
-
+#if NETCOREAPP3_1
+        public override ValueTask DisposeAsync()
+#else
        public Task DisposeAsync()
+#endif
        {
            IsConnected = false;

@@ -50,8 +53,15 @@ namespace MQTTnet.AspNetCore.Client.Tcp

            _socket?.Dispose();

+#if NETCOREAPP3_1
+
+            return base.DisposeAsync();
+        }
+#else
+
            return Task.CompletedTask;
        }
+#endif

        public async Task StartAsync()
        {
@@ -1,14 +1,13 @@
 using System;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.DependencyInjection;
-using System.Linq;
 using MQTTnet.Server;
-using System.Collections.Generic;

-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore.Extensions
 {
    public static class ApplicationBuilderExtensions
    {
+        [Obsolete("This class is obsolete and will be removed in a future version. The recommended alternative is to use MapMqtt inside Microsoft.AspNetCore.Builder.UseEndpoints(...).")]
        public static IApplicationBuilder UseMqttEndpoint(this IApplicationBuilder app, string path = "/mqtt")
        {
            app.UseWebSockets();
@@ -24,7 +23,7 @@ namespace MQTTnet.AspNetCore

                if (context.Request.Headers.TryGetValue("Sec-WebSocket-Protocol", out var requestedSubProtocolValues))
                {
-                    subProtocol = SelectSubProtocol(requestedSubProtocolValues);
+                    subProtocol = MqttSubProtocolSelector.SelectSubProtocol(requestedSubProtocolValues);
                }

                var adapter = app.ApplicationServices.GetRequiredService<MqttWebSocketServerAdapter>();
@@ -37,14 +36,6 @@ namespace MQTTnet.AspNetCore
            return app;
        }

-        public static string SelectSubProtocol(IList<string> requestedSubProtocolValues)
-        {
-            // Order the protocols to also match "mqtt", "mqttv-3.1", "mqttv-3.11" etc.
-            return requestedSubProtocolValues
-                .OrderByDescending(p => p.Length)
-                .FirstOrDefault(p => p.ToLower().StartsWith("mqtt"));
-        }
-
        public static IApplicationBuilder UseMqttServer(this IApplicationBuilder app, Action<IMqttServer> configure)
        {
            var server = app.ApplicationServices.GetRequiredService<IMqttServer>();
@@ -1,6 +1,6 @@
 using Microsoft.AspNetCore.Connections;

-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore.Extensions
 {
    public static class ConnectionBuilderExtensions
    {
@@ -0,0 +1,23 @@
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Http.Connections;
+
+#if NETCOREAPP3_1
+using System;
+#endif
+
+namespace MQTTnet.AspNetCore.Extensions
+{
+    public static class ConnectionRouteBuilderExtensions
+    {
+#if NETCOREAPP3_1
+        [Obsolete("This class is obsolete and will be removed in a future version. The recommended alternative is to use MapMqtt inside Microsoft.AspNetCore.Builder.UseEndpoints(...).")]
+#endif
+        public static void MapMqtt(this ConnectionsRouteBuilder connection, PathString path)
+        {
+            connection.MapConnectionHandler<MqttConnectionHandler>(path, options =>
+            {
+                options.WebSockets.SubProtocolSelector = MqttSubProtocolSelector.SelectSubProtocol;
+            });
+        }
+    }
+}
@@ -0,0 +1,21 @@
+
+#if NETCOREAPP3_1
+
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Routing;
+
+namespace MQTTnet.AspNetCore
+{
+    public static class EndpointRouterExtensions
+    {
+        public static void MapMqtt(this IEndpointRouteBuilder endpoints, string pattern) 
+        {
+            endpoints.MapConnectionHandler<MqttConnectionHandler>(pattern, options =>
+            {
+                options.WebSockets.SubProtocolSelector = MqttSubProtocolSelector.SelectSubProtocol;
+            });
+        }
+    }
+}
+
+#endif
@@ -5,7 +5,7 @@ using MQTTnet.Exceptions;
 using MQTTnet.Formatter;
 using MQTTnet.Packets;

-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore.Extensions
 {
    public static class ReaderExtensions
    {
@@ -80,7 +80,7 @@ namespace MQTTnet.AspNetCore
            headerLength = 0;
            bodyLength = 0;
            
-            var temp = input.Slice(0, Math.Min(5, input.Length)).GetMemory();
+            var temp = input.Slice(0, Math.Min(5, input.Length)).GetMemory().Span;

            do
            {
@@ -88,7 +88,7 @@ namespace MQTTnet.AspNetCore
                {
                    return false;
                }
-                encodedByte = temp.Span[index];
+                encodedByte = temp[index];
                index++;

                value += (byte)(encodedByte & 127) * multiplier;
@@ -3,17 +3,17 @@ using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using MQTTnet.Adapter;
 using MQTTnet.Diagnostics;
-using MQTTnet.Server;
 using MQTTnet.Implementations;
+using MQTTnet.Server;

-namespace MQTTnet.AspNetCore
+namespace MQTTnet.AspNetCore.Extensions
 {
    public static class ServiceCollectionExtensions
    {
        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, IMqttServerOptions options)
        {
            if (options == null) throw new ArgumentNullException(nameof(options));
-            
+
            services.AddSingleton(options);

            services.AddHostedMqttServer();
@@ -23,7 +23,8 @@ namespace MQTTnet.AspNetCore

        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, Action<MqttServerOptionsBuilder> configure)
        {
-            services.AddSingleton<IMqttServerOptions>(s => {
+            services.AddSingleton<IMqttServerOptions>(s =>
+            {
                var builder = new MqttServerOptionsBuilder();
                configure(builder);
                return builder.Build();
@@ -36,7 +37,8 @@ namespace MQTTnet.AspNetCore

        public static IServiceCollection AddHostedMqttServerWithServices(this IServiceCollection services, Action<AspNetMqttServerOptionsBuilder> configure)
        {
-            services.AddSingleton<IMqttServerOptions>(s => {
+            services.AddSingleton<IMqttServerOptions>(s =>
+            {
                var builder = new AspNetMqttServerOptionsBuilder(s);
                configure(builder);
                return builder.Build();
@@ -60,14 +62,12 @@ namespace MQTTnet.AspNetCore
        private static IServiceCollection AddHostedMqttServer(this IServiceCollection services)
        {
            var logger = new MqttNetLogger();
-            var childLogger = logger.CreateChildLogger();

            services.AddSingleton<IMqttNetLogger>(logger);
-            services.AddSingleton(childLogger);
            services.AddSingleton<MqttHostedServer>();
            services.AddSingleton<IHostedService>(s => s.GetService<MqttHostedServer>());
            services.AddSingleton<IMqttServer>(s => s.GetService<MqttHostedServer>());
-            
+
            return services;
        }

@@ -1,24 +1,32 @@
 <Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;netcoreapp2.1</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;netcoreapp2.1;netcoreapp3.1</TargetFrameworks>
    <Product />
    <Company />
    <Authors />
    <PackageId />
    <LangVersion>7.2</LangVersion>
    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <PublishRepositoryUrl>true</PublishRepositoryUrl>
+    <IncludeSymbols>true</IncludeSymbols>
+    <SymbolPackageFormat>snupkg</SymbolPackageFormat>
  </PropertyGroup>

+  <ItemGroup>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
+  </ItemGroup>
+
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
    <DefineConstants>RELEASE;NETSTANDARD2_0</DefineConstants>
  </PropertyGroup>

-  <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.Connections.Abstractions" Version="2.1.3" />
-    <PackageReference Include="Microsoft.AspNetCore.Http.Connections" Version="1.0.3" />
-    <PackageReference Include="Microsoft.AspNetCore.WebSockets" Version="2.1.1" />
-    <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="2.1.1" />
+  <ItemGroup Condition="'$(TargetFramework)' == 'netcoreapp3.1'">
+    <FrameworkReference Include="Microsoft.AspNetCore.App" />
+  </ItemGroup>
+    
+  <ItemGroup Condition="'$(TargetFramework)' != 'netcoreapp3.1'">
+    <PackageReference Include="Microsoft.AspNetCore.Http.Connections" Version="1.1.0" />
  </ItemGroup>

  <ItemGroup>
@@ -10,11 +10,19 @@ using System.IO.Pipelines;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
+using MQTTnet.AspNetCore.Extensions;
+using MQTTnet.Internal;

 namespace MQTTnet.AspNetCore
 {
-    public class MqttConnectionContext : IMqttChannelAdapter
+    public sealed class MqttConnectionContext : IMqttChannelAdapter
    {
+        readonly AsyncLock _writerLock = new AsyncLock();
+        readonly SpanBasedMqttPacketBodyReader _reader;
+        
+        PipeReader _input;
+        PipeWriter _output;
+        
        public MqttConnectionContext(MqttPacketFormatterAdapter packetFormatterAdapter, ConnectionContext connection)
        {
            PacketFormatterAdapter = packetFormatterAdapter ?? throw new ArgumentNullException(nameof(packetFormatterAdapter));
@@ -25,18 +33,20 @@ namespace MQTTnet.AspNetCore
                _input = Connection.Transport.Input;
                _output = Connection.Transport.Output;
            }
-            
+
            _reader = new SpanBasedMqttPacketBodyReader();
        }

-        private PipeReader _input;
-        private PipeWriter _output;
-        private readonly SpanBasedMqttPacketBodyReader _reader;
-
        public string Endpoint
        {
            get
            {
+#if NETCOREAPP3_1
+                if (Connection?.RemoteEndPoint != null)
+                {
+                    return Connection.RemoteEndPoint.ToString();
+                }
+#endif
                var connection = Http?.HttpContext?.Connection;
                if (connection == null)
                {
@@ -51,9 +61,8 @@ namespace MQTTnet.AspNetCore

        public X509Certificate2 ClientCertificate => Http?.HttpContext?.Connection?.ClientCertificate;

-        private IHttpContextFeature Http => Connection.Features.Get<IHttpContextFeature>();
-
        public ConnectionContext Connection { get; }
+        
        public MqttPacketFormatterAdapter PacketFormatterAdapter { get; }

        public long BytesSent { get; set; }
@@ -62,7 +71,7 @@ namespace MQTTnet.AspNetCore
        public Action ReadingPacketStartedCallback { get; set; }
        public Action ReadingPacketCompletedCallback { get; set; }

-        private readonly SemaphoreSlim _writerSemaphore = new SemaphoreSlim(1, 1);
+        IHttpContextFeature Http => Connection.Features.Get<IHttpContextFeature>();

        public async Task ConnectAsync(TimeSpan timeout, CancellationToken cancellationToken)
        {
@@ -136,6 +145,13 @@ namespace MQTTnet.AspNetCore
                    }
                }
            }
+            catch (Exception e)
+            {
+                // completing the cannels makes sure that there is no more data read after a protocol error
+                _input?.Complete(e);
+                _output?.Complete(e);
+                throw;
+            }
            finally
            {
                ReadingPacketCompletedCallback?.Invoke();
@@ -154,23 +170,17 @@ namespace MQTTnet.AspNetCore
        public async Task SendPacketAsync(MqttBasePacket packet, TimeSpan timeout, CancellationToken cancellationToken)
        {
            var formatter = PacketFormatterAdapter;
-
-
-            await _writerSemaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
-            try
+            using (await _writerLock.WaitAsync(cancellationToken).ConfigureAwait(false))
            {
                var buffer = formatter.Encode(packet);
                var msg = buffer.AsMemory();
                var output = _output;
-                msg.CopyTo(output.GetMemory(msg.Length));
-                BytesSent += msg.Length;
+                var result = await output.WriteAsync(msg, cancellationToken).ConfigureAwait(false);
+                if (result.IsCompleted)
+                {
+                    BytesSent += msg.Length;
+                }
                PacketFormatterAdapter.FreeBuffer();
-                output.Advance(msg.Length);
-                await output.FlushAsync().ConfigureAwait(false);
-            }
-            finally
-            {
-                _writerSemaphore.Release();
            }
        }

@@ -14,14 +14,15 @@ namespace MQTTnet.AspNetCore
        private readonly IMqttServerOptions _options;

        public MqttHostedServer(IMqttServerOptions options, IEnumerable<IMqttServerAdapter> adapters, IMqttNetLogger logger) 
-            : base(adapters, logger.CreateChildLogger(nameof(MqttHostedServer)))
+            : base(adapters, logger)
        {
            _options = options ?? throw new ArgumentNullException(nameof(options));
        }

        public Task StartAsync(CancellationToken cancellationToken)
        {
-            return StartAsync(_options);
+            _ = StartAsync(_options);
+            return Task.CompletedTask;
        }

        public Task StopAsync(CancellationToken cancellationToken)
@@ -0,0 +1,33 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.AspNetCore.Http;
+
+namespace MQTTnet.AspNetCore
+{
+    public static class MqttSubProtocolSelector
+    {
+        public static string SelectSubProtocol(HttpRequest request)
+        {
+            if (request == null) throw new ArgumentNullException(nameof(request));
+
+            string subProtocol = null;
+            if (request.Headers.TryGetValue("Sec-WebSocket-Protocol", out var requestedSubProtocolValues))
+            {
+                subProtocol = SelectSubProtocol(requestedSubProtocolValues);
+            }
+
+            return subProtocol;
+        }
+        
+        public static string SelectSubProtocol(IList<string> requestedSubProtocolValues)
+        {
+            if (requestedSubProtocolValues == null) throw new ArgumentNullException(nameof(requestedSubProtocolValues));
+
+            // Order the protocols to also match "mqtt", "mqttv-3.1", "mqttv-3.11" etc.
+            return requestedSubProtocolValues
+                .OrderByDescending(p => p.Length)
+                .FirstOrDefault(p => p.ToLower().StartsWith("mqtt"));
+        }
+    }
+}
@@ -1,24 +1,22 @@
-using System;
-using System.Net.WebSockets;
-using System.Threading.Tasks;
-using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Http;
 using MQTTnet.Adapter;
 using MQTTnet.Diagnostics;
 using MQTTnet.Formatter;
 using MQTTnet.Implementations;
 using MQTTnet.Server;
+using System;
+using System.Net.WebSockets;
+using System.Threading.Tasks;

 namespace MQTTnet.AspNetCore
 {
-    public class MqttWebSocketServerAdapter : IMqttServerAdapter
+    public sealed class MqttWebSocketServerAdapter : IMqttServerAdapter
    {
-        private readonly IMqttNetChildLogger _logger;
+        readonly IMqttNetLogger _rootLogger;

-        public MqttWebSocketServerAdapter(IMqttNetChildLogger logger)
+        public MqttWebSocketServerAdapter(IMqttNetLogger logger)
        {
-            if (logger == null) throw new ArgumentNullException(nameof(logger));
-
-            _logger = logger.CreateChildLogger(nameof(MqttTcpServerAdapter));
+            _rootLogger = logger ?? throw new ArgumentNullException(nameof(logger));
        }

        public Func<IMqttChannelAdapter, Task> ClientHandler { get; set; }
@@ -38,7 +36,7 @@ namespace MQTTnet.AspNetCore
            if (webSocket == null) throw new ArgumentNullException(nameof(webSocket));

            var endpoint = $"{httpContext.Connection.RemoteIpAddress}:{httpContext.Connection.RemotePort}";
-            
+
            var clientCertificate = await httpContext.Connection.GetClientCertificateAsync().ConfigureAwait(false);
            try
            {
@@ -51,7 +49,7 @@ namespace MQTTnet.AspNetCore
                    var formatter = new MqttPacketFormatterAdapter(writer);
                    var channel = new MqttWebSocketChannel(webSocket, endpoint, isSecureConnection, clientCertificate);

-                    using (var channelAdapter = new MqttChannelAdapter(channel, formatter, _logger.CreateChildLogger(nameof(MqttWebSocketServerAdapter))))
+                    using (var channelAdapter = new MqttChannelAdapter(channel, formatter, _rootLogger))
                    {
                        await clientHandler(channelAdapter).ConfigureAwait(false);
                    }
@@ -8,9 +8,9 @@ namespace MQTTnet.AspNetCore
 {
    public class SpanBasedMqttPacketBodyReader : IMqttPacketBodyReader
    {
-        private ReadOnlyMemory<byte> _buffer;
+        ReadOnlyMemory<byte> _buffer;

-        private int _offset;
+        int _offset;
        
        public void SetBuffer(ReadOnlyMemory<byte> buffer)
        {
@@ -38,16 +38,6 @@ namespace MQTTnet.AspNetCore
        {
            return ReadSegmentWithLengthPrefix().ToArray();
        }
-
-        private ReadOnlySpan<byte> ReadSegmentWithLengthPrefix()
-        {
-            var span = _buffer.Span;
-            var length = BinaryPrimitives.ReadUInt16BigEndian(span.Slice(_offset));
-
-            var result = span.Slice(_offset+2, length);
-            _offset += 2 + length;
-            return result;
-        }
        
        public unsafe string ReadStringWithLengthPrefix()
        {
@@ -121,5 +111,19 @@ namespace MQTTnet.AspNetCore
        {
            _offset = position;
        }
+
+        ReadOnlySpan<byte> ReadSegmentWithLengthPrefix()
+        {
+            var span = _buffer.Span;
+            var length = BinaryPrimitives.ReadUInt16BigEndian(span.Slice(_offset));
+
+            if (Length < _offset + length)
+            {
+                throw new MqttProtocolViolationException($"Expected at least {_offset + 2 + length} bytes but there are only {Length} bytes");
+            }
+            var result = span.Slice(_offset + 2, length);
+            _offset += 2 + length;
+            return result;
+        }
    }
 }
@@ -8,16 +8,15 @@ namespace MQTTnet.AspNetCore
 {
    public class SpanBasedMqttPacketWriter : IMqttPacketWriter
    {
-        private readonly ArrayPool<byte> _pool;
+        readonly ArrayPool<byte> _pool = ArrayPool<byte>.Create();

        public SpanBasedMqttPacketWriter()
        {
-            _pool = ArrayPool<byte>.Create();
-            
+            Reset(0);
        }

-        private byte[] _buffer;
-        private int _position;
+        byte[] _buffer;
+        int _position;

        public int Length { get; set; }

@@ -64,7 +63,6 @@ namespace MQTTnet.AspNetCore

            GrowIfNeeded(propertyWriter.Length);
            Write(propertyWriter.GetBuffer(), 0, propertyWriter.Length);
-            Commit(propertyWriter.Length);
        }

        public void Write(byte[] payload, int start, int length)
@@ -113,7 +111,7 @@ namespace MQTTnet.AspNetCore
            Commit(payload.Length);
        }

-        private void Commit(int count)
+        void Commit(int count)
        {
            if (_position == Length)
            {
@@ -123,7 +121,7 @@ namespace MQTTnet.AspNetCore
            _position += count;
        }

-        private void GrowIfNeeded(int requiredAdditional) 
+        void GrowIfNeeded(int requiredAdditional) 
        {
            var requiredTotal = _position + requiredAdditional;
            if (_buffer.Length >= requiredTotal)
@@ -1,8 +1,9 @@
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
-using MQTTnet.Client.Connecting;
+using MQTTnet.Client.Connecting;
 using MQTTnet.Client.Disconnecting;
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;

 namespace MQTTnet.Extensions.ManagedClient
 {
@@ -21,11 +22,12 @@ namespace MQTTnet.Extensions.ManagedClient

        IConnectingFailedHandler ConnectingFailedHandler { get; set; }
        ISynchronizingSubscriptionsFailedHandler SynchronizingSubscriptionsFailedHandler { get; set; }
-        
+
        Task StartAsync(IManagedMqttClientOptions options);
        Task StopAsync();
+        Task PingAsync(CancellationToken cancellationToken);

-        Task SubscribeAsync(IEnumerable<TopicFilter> topicFilters);
+        Task SubscribeAsync(IEnumerable<MqttTopicFilter> topicFilters);
        Task UnsubscribeAsync(IEnumerable<string> topics);

        Task PublishAsync(ManagedMqttApplicationMessage applicationMessages);
@@ -1,20 +1,23 @@
 <Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
-    <TargetFrameworks>netstandard1.3;netstandard2.0</TargetFrameworks>
+    <TargetFrameworks>netstandard1.3;netstandard2.0;netstandard2.1</TargetFrameworks>
    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461</TargetFrameworks>
    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' AND '$(MSBuildRuntimeType)' != 'Core' AND '$(SolutionName)' != 'MQTTnet.noUWP' ">$(TargetFrameworks);uap10.0</TargetFrameworks>
    <Product />
    <Company />
    <Authors />
    <PackageId />
+    <PublishRepositoryUrl>true</PublishRepositoryUrl>
+    <IncludeSymbols>true</IncludeSymbols>
+    <SymbolPackageFormat>snupkg</SymbolPackageFormat>
  </PropertyGroup>

  <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0'">
    <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>
    <NugetTargetMoniker>UAP,Version=v10.0</NugetTargetMoniker>
    <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
-    <TargetPlatformVersion>10.0.17134.0</TargetPlatformVersion>
+    <TargetPlatformVersion>10.0.18362.0</TargetPlatformVersion>
    <TargetPlatformMinVersion>10.0.10240.0</TargetPlatformMinVersion>
    <TargetFrameworkIdentifier>.NETCore</TargetFrameworkIdentifier>
    <TargetFrameworkVersion>v5.0</TargetFrameworkVersion>
@@ -23,6 +26,10 @@
    <LanguageTargets>$(MSBuildExtensionsPath)\Microsoft\WindowsXaml\v$(VisualStudioVersion)\Microsoft.Windows.UI.Xaml.CSharp.targets</LanguageTargets>
  </PropertyGroup>

+  <ItemGroup>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
+  </ItemGroup>
+
  <ItemGroup>
    <ProjectReference Include="..\MQTTnet\MQTTnet.csproj" />
  </ItemGroup>
@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Client;
+using MQTTnet.Client;
 using MQTTnet.Client.Connecting;
 using MQTTnet.Client.Disconnecting;
 using MQTTnet.Client.Publishing;
@@ -13,17 +8,34 @@ using MQTTnet.Exceptions;
 using MQTTnet.Internal;
 using MQTTnet.Protocol;
 using MQTTnet.Server;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;

 namespace MQTTnet.Extensions.ManagedClient
 {
-    public class ManagedMqttClient : IManagedMqttClient
+    public class ManagedMqttClient : Disposable, IManagedMqttClient
    {
        private readonly BlockingQueue<ManagedMqttApplicationMessage> _messageQueue = new BlockingQueue<ManagedMqttApplicationMessage>();
+
+        /// <summary>
+        /// The subscriptions are managed in 2 separate buckets:
+        /// <see cref="_subscriptions"/> and <see cref="_unsubscriptions"/> are processed during normal operation
+        /// and are moved to the <see cref="_reconnectSubscriptions"/> when they get processed. They can be accessed by
+        /// any thread and are therefore mutex'ed. <see cref="_reconnectSubscriptions"/> get sent to the broker
+        ///  at reconnect and are solely owned by <see cref="MaintainConnectionAsync"/>.
+        /// </summary>
+        private readonly Dictionary<string, MqttQualityOfServiceLevel> _reconnectSubscriptions = new Dictionary<string, MqttQualityOfServiceLevel>();
        private readonly Dictionary<string, MqttQualityOfServiceLevel> _subscriptions = new Dictionary<string, MqttQualityOfServiceLevel>();
        private readonly HashSet<string> _unsubscriptions = new HashSet<string>();
+        private readonly SemaphoreSlim _subscriptionsQueuedSignal = new SemaphoreSlim(0);

        private readonly IMqttClient _mqttClient;
-        private readonly IMqttNetChildLogger _logger;
+        private readonly IMqttNetScopedLogger _logger;
+
+        private readonly AsyncLock _messageQueueLock = new AsyncLock();

        private CancellationTokenSource _connectionCancellationToken;
        private CancellationTokenSource _publishingCancellationToken;
@@ -31,15 +43,12 @@ namespace MQTTnet.Extensions.ManagedClient

        private ManagedMqttClientStorageManager _storageManager;

-        private bool _disposed;
-        private bool _subscriptionsNotPushed;
-
-        public ManagedMqttClient(IMqttClient mqttClient, IMqttNetChildLogger logger)
+        public ManagedMqttClient(IMqttClient mqttClient, IMqttNetLogger logger)
        {
            _mqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));

            if (logger == null) throw new ArgumentNullException(nameof(logger));
-            _logger = logger.CreateChildLogger(nameof(ManagedMqttClient));
+            _logger = logger.CreateScopedLogger(nameof(ManagedMqttClient));
        }

        public bool IsConnected => _mqttClient.IsConnected;
@@ -80,10 +89,6 @@ namespace MQTTnet.Extensions.ManagedClient
            if (options == null) throw new ArgumentNullException(nameof(options));
            if (options.ClientOptions == null) throw new ArgumentException("The client options are not set.", nameof(options));

-            if (!options.ClientOptions.CleanSession)
-            {
-                throw new NotSupportedException("The managed client does not support existing sessions.");
-            }

            if (!_maintainConnectionTask?.IsCompleted ?? false) throw new InvalidOperationException("The managed client is already started.");

@@ -124,6 +129,11 @@ namespace MQTTnet.Extensions.ManagedClient
            }
        }

+        public Task PingAsync(CancellationToken cancellationToken)
+        {
+            return _mqttClient.PingAsync(cancellationToken);
+        }
+
        public async Task<MqttClientPublishResult> PublishAsync(MqttApplicationMessage applicationMessage, CancellationToken cancellationToken)
        {
            ThrowIfDisposed();
@@ -139,6 +149,7 @@ namespace MQTTnet.Extensions.ManagedClient
            ThrowIfDisposed();

            if (applicationMessage == null) throw new ArgumentNullException(nameof(applicationMessage));
+            if (Options == null) throw new InvalidOperationException("call StartAsync before publishing messages");

            MqttTopicValidator.ThrowIfInvalid(applicationMessage.ApplicationMessage.Topic);

@@ -147,7 +158,7 @@ namespace MQTTnet.Extensions.ManagedClient

            try
            {
-                lock (_messageQueue)
+                using (await _messageQueueLock.WaitAsync(CancellationToken.None).ConfigureAwait(false))
                {
                    if (_messageQueue.Count >= Options.MaxPendingMessages)
                    {
@@ -167,6 +178,16 @@ namespace MQTTnet.Extensions.ManagedClient
                    }

                    _messageQueue.Enqueue(applicationMessage);
+
+                    if (_storageManager != null)
+                    {
+                        if (removedMessage != null)
+                        {
+                            await _storageManager.RemoveAsync(removedMessage).ConfigureAwait(false);
+                        }
+
+                        await _storageManager.AddAsync(applicationMessage).ConfigureAwait(false);
+                    }
                }
            }
            finally
@@ -181,19 +202,9 @@ namespace MQTTnet.Extensions.ManagedClient
                }

            }
-            
-            if (_storageManager != null)
-            {
-                if (removedMessage != null)
-                {
-                    await _storageManager.RemoveAsync(removedMessage).ConfigureAwait(false);
-                }
-
-                await _storageManager.AddAsync(applicationMessage).ConfigureAwait(false);
-            }
        }

-        public Task SubscribeAsync(IEnumerable<TopicFilter> topicFilters)
+        public Task SubscribeAsync(IEnumerable<MqttTopicFilter> topicFilters)
        {
            ThrowIfDisposed();

@@ -204,9 +215,10 @@ namespace MQTTnet.Extensions.ManagedClient
                foreach (var topicFilter in topicFilters)
                {
                    _subscriptions[topicFilter.Topic] = topicFilter.QualityOfServiceLevel;
-                    _subscriptionsNotPushed = true;
+                    _unsubscriptions.Remove(topicFilter.Topic);
                }
            }
+            _subscriptionsQueuedSignal.Release();

            return Task.FromResult(0);
        }
@@ -221,44 +233,34 @@ namespace MQTTnet.Extensions.ManagedClient
            {
                foreach (var topic in topics)
                {
-                    if (_subscriptions.Remove(topic))
-                    {
-                        _unsubscriptions.Add(topic);
-                        _subscriptionsNotPushed = true;
-                    }
+                    _subscriptions.Remove(topic);
+                    _unsubscriptions.Add(topic);
                }
            }
+            _subscriptionsQueuedSignal.Release();

            return Task.FromResult(0);
        }

-        public void Dispose()
+        protected override void Dispose(bool disposing)
        {
-            if (_disposed)
+            if (disposing)
            {
-                return;
-            }
-
-            _disposed = true;
-
-            StopPublishing();
-            StopMaintainingConnection();
-
-            if (_maintainConnectionTask != null)
-            {
-                Task.WaitAny(_maintainConnectionTask);
-                _maintainConnectionTask = null;
-            }
-
-            _mqttClient.Dispose();
-        }
-
-        private void ThrowIfDisposed()
-        {
-            if (_disposed)
-            {
-                throw new ObjectDisposedException(nameof(ManagedMqttClient));
+                StopPublishing();
+                StopMaintainingConnection();
+
+                if (_maintainConnectionTask != null)
+                {
+                    _maintainConnectionTask.GetAwaiter().GetResult();
+                    _maintainConnectionTask = null;
+                }
+
+                _messageQueue.Dispose();
+                _messageQueueLock.Dispose();
+                _mqttClient.Dispose();
+                _subscriptionsQueuedSignal.Dispose();
            }
+            base.Dispose(disposing);
        }

        private async Task MaintainConnectionAsync(CancellationToken cancellationToken)
@@ -275,11 +277,11 @@ namespace MQTTnet.Extensions.ManagedClient
            }
            catch (Exception exception)
            {
-                _logger.Error(exception, "Unhandled exception while maintaining connection.");
+                _logger.Error(exception, "Error exception while maintaining connection.");
            }
            finally
            {
-                if (!_disposed)
+                if (!IsDisposed)
                {
                    try
                    {
@@ -292,6 +294,12 @@ namespace MQTTnet.Extensions.ManagedClient

                    _logger.Info("Stopped");
                }
+                _reconnectSubscriptions.Clear();
+                lock (_subscriptions)
+                {
+                    _subscriptions.Clear();
+                    _unsubscriptions.Clear();
+                }
            }
        }

@@ -307,16 +315,22 @@ namespace MQTTnet.Extensions.ManagedClient
                    return;
                }

-                if (connectionState == ReconnectionResult.Reconnected || _subscriptionsNotPushed)
+                if (connectionState == ReconnectionResult.Reconnected)
+                {
+                    await PublishReconnectSubscriptionsAsync().ConfigureAwait(false);
+                    StartPublishing();
+                    return;
+                }
+
+                if (connectionState == ReconnectionResult.Recovered)
                {
-                    await SynchronizeSubscriptionsAsync().ConfigureAwait(false);
                    StartPublishing();
                    return;
                }

                if (connectionState == ReconnectionResult.StillConnected)
                {
-                    await Task.Delay(Options.ConnectionCheckInterval, cancellationToken).ConfigureAwait(false);
+                    await PublishSubscriptionsAsync(Options.ConnectionCheckInterval, cancellationToken).ConfigureAwait(false);
                }
            }
            catch (OperationCanceledException)
@@ -324,11 +338,11 @@ namespace MQTTnet.Extensions.ManagedClient
            }
            catch (MqttCommunicationException exception)
            {
-                _logger.Warning(exception, "Communication exception while maintaining connection.");
+                _logger.Warning(exception, "Communication error while maintaining connection.");
            }
            catch (Exception exception)
            {
-                _logger.Error(exception, "Unhandled exception while maintaining connection.");
+                _logger.Error(exception, "Error exception while maintaining connection.");
            }
        }

@@ -346,7 +360,7 @@ namespace MQTTnet.Extensions.ManagedClient
                    // of the messages, the DropOldestQueuedMessage strategy would
                    // be unable to know which message is actually the oldest and would
                    // instead drop the first item in the queue.
-                    var message = _messageQueue.PeekAndWait();
+                    var message = _messageQueue.PeekAndWait(cancellationToken);
                    if (message == null)
                    {
                        continue;
@@ -362,7 +376,7 @@ namespace MQTTnet.Extensions.ManagedClient
            }
            catch (Exception exception)
            {
-                _logger.Error(exception, "Unhandled exception while publishing queued application messages.");
+                _logger.Error(exception, "Error while publishing queued application messages.");
            }
            finally
            {
@@ -377,7 +391,7 @@ namespace MQTTnet.Extensions.ManagedClient
            {
                await _mqttClient.PublishAsync(message.ApplicationMessage).ConfigureAwait(false);

-                lock (_messageQueue) //lock to avoid conflict with this.PublishAsync
+                using (await _messageQueueLock.WaitAsync(CancellationToken.None).ConfigureAwait(false)) //lock to avoid conflict with this.PublishAsync
                {
                    // While publishing this message, this.PublishAsync could have booted this
                    // message off the queue to make room for another (when using a cap
@@ -386,11 +400,11 @@ namespace MQTTnet.Extensions.ManagedClient
                    // it from the queue.  If not, that means this.PublishAsync has already
                    // removed it, in which case we don't want to do anything.
                    _messageQueue.RemoveFirst(i => i.Id.Equals(message.Id));
-                }

-                if (_storageManager != null)
-                {
-                    await _storageManager.RemoveAsync(message).ConfigureAwait(false);
+                    if (_storageManager != null)
+                    {
+                        await _storageManager.RemoveAsync(message).ConfigureAwait(false);
+                    }
                }
            }
            catch (MqttCommunicationException exception)
@@ -408,21 +422,21 @@ namespace MQTTnet.Extensions.ManagedClient
                    //contradict the expected behavior of QoS 1 and 2, that's also true
                    //for the usage of a message queue cap, so it's still consistent
                    //with prior behavior in that way.
-                    lock (_messageQueue) //lock to avoid conflict with this.PublishAsync
+                    using (await _messageQueueLock.WaitAsync(CancellationToken.None).ConfigureAwait(false)) //lock to avoid conflict with this.PublishAsync
                    {
                        _messageQueue.RemoveFirst(i => i.Id.Equals(message.Id));
-                    }

-                    if (_storageManager != null)
-                    {
-                        await _storageManager.RemoveAsync(message).ConfigureAwait(false);
+                        if (_storageManager != null)
+                        {
+                            await _storageManager.RemoveAsync(message).ConfigureAwait(false);
+                        }
                    }
                }
            }
            catch (Exception exception)
            {
                transmitException = exception;
-                _logger.Error(exception, $"Unhandled exception while publishing application message ({message.Id}).");
+                _logger.Error(exception, $"Error while publishing application message ({message.Id}).");
            }
            finally
            {
@@ -435,50 +449,84 @@ namespace MQTTnet.Extensions.ManagedClient
            }
        }

-        private async Task SynchronizeSubscriptionsAsync()
+        private async Task PublishSubscriptionsAsync(TimeSpan timeout, CancellationToken cancellationToken)
        {
-            _logger.Info("Synchronizing subscriptions");
-
-            List<TopicFilter> subscriptions;
-            HashSet<string> unsubscriptions;
-
-            lock (_subscriptions)
+            var endTime = DateTime.UtcNow + timeout;
+            while (await _subscriptionsQueuedSignal.WaitAsync(GetRemainingTime(endTime), cancellationToken).ConfigureAwait(false))
            {
-                subscriptions = _subscriptions.Select(i => new TopicFilter { Topic = i.Key, QualityOfServiceLevel = i.Value }).ToList();
+                List<MqttTopicFilter> subscriptions;
+                HashSet<string> unsubscriptions;

-                unsubscriptions = new HashSet<string>(_unsubscriptions);
-                _unsubscriptions.Clear();
+                lock (_subscriptions)
+                {
+                    subscriptions = _subscriptions.Select(i => new MqttTopicFilter { Topic = i.Key, QualityOfServiceLevel = i.Value }).ToList();
+                    _subscriptions.Clear();
+                    unsubscriptions = new HashSet<string>(_unsubscriptions);
+                    _unsubscriptions.Clear();
+                }

-                _subscriptionsNotPushed = false;
+                if (!subscriptions.Any() && !unsubscriptions.Any())
+                {
+                    continue;
+                }
+
+                _logger.Verbose($"Publishing subscriptions ({subscriptions.Count} subscriptions and {unsubscriptions.Count} unsubscriptions)");
+
+                foreach (var unsubscription in unsubscriptions)
+                {
+                    _reconnectSubscriptions.Remove(unsubscription);
+                }
+
+                foreach (var subscription in subscriptions)
+                {
+                    _reconnectSubscriptions[subscription.Topic] = subscription.QualityOfServiceLevel;
+                }
+
+                try
+                {
+                    if (unsubscriptions.Any())
+                    {
+                        await _mqttClient.UnsubscribeAsync(unsubscriptions.ToArray()).ConfigureAwait(false);
+                    }
+
+                    if (subscriptions.Any())
+                    {
+                        await _mqttClient.SubscribeAsync(subscriptions.ToArray()).ConfigureAwait(false);
+                    }
+                }
+                catch (Exception exception)
+                {
+                    await HandleSubscriptionExceptionAsync(exception).ConfigureAwait(false);
+                }
            }
+        }

-            if (!subscriptions.Any() && !unsubscriptions.Any())
-            {
-                return;
-            }
+        private async Task PublishReconnectSubscriptionsAsync()
+        {
+            _logger.Info("Publishing subscriptions at reconnect");

            try
            {
-                if (unsubscriptions.Any())
-                {
-                    await _mqttClient.UnsubscribeAsync(unsubscriptions.ToArray()).ConfigureAwait(false);
-                }
-
-                if (subscriptions.Any())
+                if (_reconnectSubscriptions.Any())
                {
+                    var subscriptions = _reconnectSubscriptions.Select(i => new MqttTopicFilter { Topic = i.Key, QualityOfServiceLevel = i.Value });
                    await _mqttClient.SubscribeAsync(subscriptions.ToArray()).ConfigureAwait(false);
                }
            }
            catch (Exception exception)
            {
-                _logger.Warning(exception, "Synchronizing subscriptions failed.");
-                _subscriptionsNotPushed = true;
+                await HandleSubscriptionExceptionAsync(exception).ConfigureAwait(false);
+            }
+        }

-                var synchronizingSubscriptionsFailedHandler = SynchronizingSubscriptionsFailedHandler;
-                if (SynchronizingSubscriptionsFailedHandler != null)
-                {
-                    await synchronizingSubscriptionsFailedHandler.HandleSynchronizingSubscriptionsFailedAsync(new ManagedProcessFailedEventArgs(exception)).ConfigureAwait(false);
-                }
+        private async Task HandleSubscriptionExceptionAsync(Exception exception)
+        {
+            _logger.Warning(exception, "Synchronizing subscriptions failed.");
+
+            var synchronizingSubscriptionsFailedHandler = SynchronizingSubscriptionsFailedHandler;
+            if (SynchronizingSubscriptionsFailedHandler != null)
+            {
+                await synchronizingSubscriptionsFailedHandler.HandleSynchronizingSubscriptionsFailedAsync(new ManagedProcessFailedEventArgs(exception)).ConfigureAwait(false);
            }
        }

@@ -491,8 +539,8 @@ namespace MQTTnet.Extensions.ManagedClient

            try
            {
-                await _mqttClient.ConnectAsync(Options.ClientOptions).ConfigureAwait(false);
-                return ReconnectionResult.Reconnected;
+                var result = await _mqttClient.ConnectAsync(Options.ClientOptions).ConfigureAwait(false);
+                return result.IsSessionPresent ? ReconnectionResult.Recovered : ReconnectionResult.Reconnected;
            }
            catch (Exception exception)
            {
@@ -505,7 +553,7 @@ namespace MQTTnet.Extensions.ManagedClient
                return ReconnectionResult.NotConnected;
            }
        }
-        
+
        private void StartPublishing()
        {
            if (_publishingCancellationToken != null)
@@ -532,5 +580,11 @@ namespace MQTTnet.Extensions.ManagedClient
            _connectionCancellationToken?.Dispose();
            _connectionCancellationToken = null;
        }
+
+        private TimeSpan GetRemainingTime(DateTime endTime)
+        {
+            var remainingTime = endTime - DateTime.UtcNow;
+            return remainingTime < TimeSpan.Zero ? TimeSpan.Zero : remainingTime;
+        }
    }
-}
+}
@@ -1,12 +1,12 @@
-using System;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Client.Connecting;
+using MQTTnet.Client.Connecting;
 using MQTTnet.Client.Disconnecting;
 using MQTTnet.Client.Publishing;
 using MQTTnet.Client.Receiving;
 using MQTTnet.Protocol;
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;

 namespace MQTTnet.Extensions.ManagedClient
 {
@@ -76,39 +76,42 @@ namespace MQTTnet.Extensions.ManagedClient
            return client;
        }

-        public static IManagedMqttClient UseApplicationMessageReceivedHandler(this IManagedMqttClient client, Func<MqttApplicationMessageReceivedEventArgs, Task> handler)
+        public static TReceiver UseApplicationMessageReceivedHandler<TReceiver>(this TReceiver receiver, Func<MqttApplicationMessageReceivedEventArgs, Task> handler)
+            where TReceiver : IApplicationMessageReceiver
        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (receiver == null) throw new ArgumentNullException(nameof(receiver));

            if (handler == null)
            {
-                return client.UseApplicationMessageReceivedHandler((IMqttApplicationMessageReceivedHandler)null);
+                return receiver.UseApplicationMessageReceivedHandler((IMqttApplicationMessageReceivedHandler)null);
            }

-            return client.UseApplicationMessageReceivedHandler(new MqttApplicationMessageReceivedHandlerDelegate(handler));
+            return receiver.UseApplicationMessageReceivedHandler(new MqttApplicationMessageReceivedHandlerDelegate(handler));
        }

-        public static IManagedMqttClient UseApplicationMessageReceivedHandler(this IManagedMqttClient client, Action<MqttApplicationMessageReceivedEventArgs> handler)
+        public static TReceiver UseApplicationMessageReceivedHandler<TReceiver>(this TReceiver receiver, Action<MqttApplicationMessageReceivedEventArgs> handler)
+            where TReceiver : IApplicationMessageReceiver
        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (receiver == null) throw new ArgumentNullException(nameof(receiver));

            if (handler == null)
            {
-                return client.UseApplicationMessageReceivedHandler((IMqttApplicationMessageReceivedHandler)null);
+                return receiver.UseApplicationMessageReceivedHandler((IMqttApplicationMessageReceivedHandler)null);
            }

-            return client.UseApplicationMessageReceivedHandler(new MqttApplicationMessageReceivedHandlerDelegate(handler));
+            return receiver.UseApplicationMessageReceivedHandler(new MqttApplicationMessageReceivedHandlerDelegate(handler));
        }

-        public static IManagedMqttClient UseApplicationMessageReceivedHandler(this IManagedMqttClient client, IMqttApplicationMessageReceivedHandler handler)
+        public static TReceiver UseApplicationMessageReceivedHandler<TReceiver>(this TReceiver receiver, IMqttApplicationMessageReceivedHandler handler)
+            where TReceiver : IApplicationMessageReceiver
        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (receiver == null) throw new ArgumentNullException(nameof(receiver));

-            client.ApplicationMessageReceivedHandler = handler;
-            return client;
+            receiver.ApplicationMessageReceivedHandler = handler;
+            return receiver;
        }

-        public static Task SubscribeAsync(this IManagedMqttClient client, params TopicFilter[] topicFilters)
+        public static Task SubscribeAsync(this IManagedMqttClient client, params MqttTopicFilter[] topicFilters)
        {
            if (client == null) throw new ArgumentNullException(nameof(client));

@@ -120,7 +123,7 @@ namespace MQTTnet.Extensions.ManagedClient
            if (client == null) throw new ArgumentNullException(nameof(client));
            if (topic == null) throw new ArgumentNullException(nameof(topic));

-            return client.SubscribeAsync(new TopicFilterBuilder().WithTopic(topic).WithQualityOfServiceLevel(qualityOfServiceLevel).Build());
+            return client.SubscribeAsync(new MqttTopicFilterBuilder().WithTopic(topic).WithQualityOfServiceLevel(qualityOfServiceLevel).Build());
        }

        public static Task SubscribeAsync(this IManagedMqttClient client, string topic)
@@ -128,7 +131,7 @@ namespace MQTTnet.Extensions.ManagedClient
            if (client == null) throw new ArgumentNullException(nameof(client));
            if (topic == null) throw new ArgumentNullException(nameof(topic));

-            return client.SubscribeAsync(new TopicFilterBuilder().WithTopic(topic).Build());
+            return client.SubscribeAsync(new MqttTopicFilterBuilder().WithTopic(topic).Build());
        }

        public static Task UnsubscribeAsync(this IManagedMqttClient client, params string[] topicFilters)
@@ -138,92 +141,92 @@ namespace MQTTnet.Extensions.ManagedClient
            return client.UnsubscribeAsync(topicFilters);
        }

-        public static async Task PublishAsync(this IManagedMqttClient client, IEnumerable<MqttApplicationMessage> applicationMessages)
+        public static async Task PublishAsync(this IApplicationMessagePublisher publisher, IEnumerable<MqttApplicationMessage> applicationMessages)
        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
            if (applicationMessages == null) throw new ArgumentNullException(nameof(applicationMessages));

            foreach (var applicationMessage in applicationMessages)
            {
-                await client.PublishAsync(applicationMessage).ConfigureAwait(false);
+                await publisher.PublishAsync(applicationMessage).ConfigureAwait(false);
            }
        }

-        public static Task<MqttClientPublishResult> PublishAsync(this IManagedMqttClient client, MqttApplicationMessage applicationMessage)
+        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, MqttApplicationMessage applicationMessage)
        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
            if (applicationMessage == null) throw new ArgumentNullException(nameof(applicationMessage));

-            return client.PublishAsync(applicationMessage, CancellationToken.None);
+            return publisher.PublishAsync(applicationMessage, CancellationToken.None);
        }

-        public static async Task PublishAsync(this IManagedMqttClient client, params MqttApplicationMessage[] applicationMessages)
+        public static async Task PublishAsync(this IApplicationMessagePublisher publisher, params MqttApplicationMessage[] applicationMessages)
        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
            if (applicationMessages == null) throw new ArgumentNullException(nameof(applicationMessages));

            foreach (var applicationMessage in applicationMessages)
            {
-                await client.PublishAsync(applicationMessage, CancellationToken.None).ConfigureAwait(false);
+                await publisher.PublishAsync(applicationMessage, CancellationToken.None).ConfigureAwait(false);
            }
        }

-        public static Task<MqttClientPublishResult> PublishAsync(this IManagedMqttClient client, string topic)
+        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, string topic)
        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
            if (topic == null) throw new ArgumentNullException(nameof(topic));

-            return client.PublishAsync(builder => builder
+            return publisher.PublishAsync(builder => builder
                .WithTopic(topic));
        }

-        public static Task<MqttClientPublishResult> PublishAsync(this IManagedMqttClient client, string topic, string payload)
+        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, string topic, string payload)
        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
            if (topic == null) throw new ArgumentNullException(nameof(topic));

-            return client.PublishAsync(builder => builder
+            return publisher.PublishAsync(builder => builder
                .WithTopic(topic)
                .WithPayload(payload));
        }

-        public static Task<MqttClientPublishResult> PublishAsync(this IManagedMqttClient client, string topic, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
+        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, string topic, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
            if (topic == null) throw new ArgumentNullException(nameof(topic));

-            return client.PublishAsync(builder => builder
+            return publisher.PublishAsync(builder => builder
                .WithTopic(topic)
                .WithPayload(payload)
                .WithQualityOfServiceLevel(qualityOfServiceLevel));
        }

-        public static Task<MqttClientPublishResult> PublishAsync(this IManagedMqttClient client, string topic, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel, bool retain)
+        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, string topic, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel, bool retain)
        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (publisher == null) throw new ArgumentNullException(nameof(publisher));
            if (topic == null) throw new ArgumentNullException(nameof(topic));

-            return client.PublishAsync(builder => builder
+            return publisher.PublishAsync(builder => builder
                .WithTopic(topic)
                .WithPayload(payload)
                .WithQualityOfServiceLevel(qualityOfServiceLevel)
                .WithRetainFlag(retain));
        }

-        public static Task<MqttClientPublishResult> PublishAsync(this IManagedMqttClient client, Func<MqttApplicationMessageBuilder, MqttApplicationMessageBuilder> builder, CancellationToken cancellationToken)
+        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, Func<MqttApplicationMessageBuilder, MqttApplicationMessageBuilder> builder, CancellationToken cancellationToken)
        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (publisher == null) throw new ArgumentNullException(nameof(publisher));

            var message = builder(new MqttApplicationMessageBuilder()).Build();
-            return client.PublishAsync(message, cancellationToken);
+            return publisher.PublishAsync(message, cancellationToken);
        }

-        public static Task<MqttClientPublishResult> PublishAsync(this IManagedMqttClient client, Func<MqttApplicationMessageBuilder, MqttApplicationMessageBuilder> builder)
+        public static Task<MqttClientPublishResult> PublishAsync(this IApplicationMessagePublisher publisher, Func<MqttApplicationMessageBuilder, MqttApplicationMessageBuilder> builder)
        {
-            if (client == null) throw new ArgumentNullException(nameof(client));
+            if (publisher == null) throw new ArgumentNullException(nameof(publisher));

            var message = builder(new MqttApplicationMessageBuilder()).Build();
-            return client.PublishAsync(message, CancellationToken.None);
+            return publisher.PublishAsync(message, CancellationToken.None);
        }
    }
 }
@@ -1,5 +1,5 @@
-using System;
-using MQTTnet.Diagnostics;
+using MQTTnet.Diagnostics;
+using System;

 namespace MQTTnet.Extensions.ManagedClient
 {
@@ -9,7 +9,7 @@ namespace MQTTnet.Extensions.ManagedClient
        {
            if (factory == null) throw new ArgumentNullException(nameof(factory));

-            return new ManagedMqttClient(factory.CreateMqttClient(), factory.DefaultLogger.CreateChildLogger());
+            return new ManagedMqttClient(factory.CreateMqttClient(), factory.DefaultLogger);
        }

        public static IManagedMqttClient CreateManagedMqttClient(this IMqttFactory factory, IMqttNetLogger logger)
@@ -17,7 +17,7 @@ namespace MQTTnet.Extensions.ManagedClient
            if (factory == null) throw new ArgumentNullException(nameof(factory));
            if (logger == null) throw new ArgumentNullException(nameof(logger));

-            return new ManagedMqttClient(factory.CreateMqttClient(logger), logger.CreateChildLogger());
+            return new ManagedMqttClient(factory.CreateMqttClient(logger), logger);
        }
    }
 }
@@ -4,6 +4,7 @@
    {
        StillConnected,
        Reconnected,
+        Recovered,
        NotConnected
    }
 }
@@ -1,20 +1,23 @@
 <Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
-    <TargetFrameworks>netstandard1.3;netstandard2.0</TargetFrameworks>
+    <TargetFrameworks>netstandard1.3;netstandard2.0;netstandard2.1</TargetFrameworks>
    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461</TargetFrameworks>
    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' AND '$(MSBuildRuntimeType)' != 'Core' AND '$(SolutionName)' != 'MQTTnet.noUWP' ">$(TargetFrameworks);uap10.0</TargetFrameworks>
    <Product />
    <Company />
    <Authors />
    <PackageId />
+    <PublishRepositoryUrl>true</PublishRepositoryUrl>
+    <IncludeSymbols>true</IncludeSymbols>
+    <SymbolPackageFormat>snupkg</SymbolPackageFormat>
  </PropertyGroup>

  <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0'">
    <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>
    <NugetTargetMoniker>UAP,Version=v10.0</NugetTargetMoniker>
    <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
-    <TargetPlatformVersion>10.0.17134.0</TargetPlatformVersion>
+    <TargetPlatformVersion>10.0.18362.0</TargetPlatformVersion>
    <TargetPlatformMinVersion>10.0.10240.0</TargetPlatformMinVersion>
    <TargetFrameworkIdentifier>.NETCore</TargetFrameworkIdentifier>
    <TargetFrameworkVersion>v5.0</TargetFrameworkVersion>
@@ -23,6 +26,10 @@
    <LanguageTargets>$(MSBuildExtensionsPath)\Microsoft\WindowsXaml\v$(VisualStudioVersion)\Microsoft.Windows.UI.Xaml.CSharp.targets</LanguageTargets>
  </PropertyGroup>

+  <ItemGroup>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
+  </ItemGroup>
+
  <ItemGroup>
    <ProjectReference Include="..\MQTTnet\MQTTnet.csproj" />
  </ItemGroup>
@@ -1,23 +1,32 @@
-using System;
+using MQTTnet.Client;
+using MQTTnet.Exceptions;
+using MQTTnet.Extensions.Rpc.Options;
+using MQTTnet.Extensions.Rpc.Options.TopicGeneration;
+using MQTTnet.Protocol;
+using System;
 using System.Collections.Concurrent;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
-using MQTTnet.Client;
-using MQTTnet.Exceptions;
-using MQTTnet.Protocol;

 namespace MQTTnet.Extensions.Rpc
 {
-    public class MqttRpcClient : IDisposable
+    public sealed class MqttRpcClient : IDisposable
    {
        private readonly ConcurrentDictionary<string, TaskCompletionSource<byte[]>> _waitingCalls = new ConcurrentDictionary<string, TaskCompletionSource<byte[]>>();
        private readonly IMqttClient _mqttClient;
+        private readonly IMqttRpcClientOptions _options;
        private readonly RpcAwareApplicationMessageReceivedHandler _applicationMessageReceivedHandler;

-        public MqttRpcClient(IMqttClient mqttClient)
+        [Obsolete("Use MqttRpcClient(IMqttClient mqttClient, IMqttRpcClientOptions options).")]
+        public MqttRpcClient(IMqttClient mqttClient) : this(mqttClient, new MqttRpcClientOptions())
+        {
+        }
+
+        public MqttRpcClient(IMqttClient mqttClient, IMqttRpcClientOptions options)
        {
            _mqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
+            _options = options ?? throw new ArgumentNullException(nameof(options));

            _applicationMessageReceivedHandler = new RpcAwareApplicationMessageReceivedHandler(
                mqttClient.ApplicationMessageReceivedHandler,
@@ -55,8 +64,26 @@ namespace MQTTnet.Extensions.Rpc
                throw new InvalidOperationException("The application message received handler was modified.");
            }

-            var requestTopic = $"MQTTnet.RPC/{Guid.NewGuid():N}/{methodName}";
-            var responseTopic = requestTopic + "/response";
+            var topicNames = _options.TopicGenerationStrategy.CreateRpcTopics(new TopicGenerationContext
+            {
+                MethodName = methodName,
+                QualityOfServiceLevel = qualityOfServiceLevel,
+                MqttClient = _mqttClient,
+                Options = _options
+            });
+
+            var requestTopic = topicNames.RequestTopic;
+            var responseTopic = topicNames.ResponseTopic;
+
+            if (string.IsNullOrWhiteSpace(requestTopic))
+            {
+                throw new MqttProtocolViolationException("RPC request topic is empty.");
+            }
+
+            if (string.IsNullOrWhiteSpace(responseTopic))
+            {
+                throw new MqttProtocolViolationException("RPC response topic is empty.");
+            }

            var requestMessage = new MqttApplicationMessageBuilder()
                .WithTopic(requestTopic)
@@ -74,7 +101,7 @@ namespace MQTTnet.Extensions.Rpc

                await _mqttClient.SubscribeAsync(responseTopic, qualityOfServiceLevel).ConfigureAwait(false);
                await _mqttClient.PublishAsync(requestMessage).ConfigureAwait(false);
-                
+
                using (var timeoutCts = new CancellationTokenSource(timeout))
                using (var linkedCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, timeoutCts.Token))
                {
@@ -0,0 +1,9 @@
+using MQTTnet.Extensions.Rpc.Options.TopicGeneration;
+
+namespace MQTTnet.Extensions.Rpc.Options
+{
+    public interface IMqttRpcClientOptions
+    {
+        IMqttRpcClientTopicGenerationStrategy TopicGenerationStrategy { get; set; }
+    }
+}
@@ -0,0 +1,9 @@
+using MQTTnet.Extensions.Rpc.Options.TopicGeneration;
+
+namespace MQTTnet.Extensions.Rpc.Options
+{
+    public class MqttRpcClientOptions : IMqttRpcClientOptions
+    {
+        public IMqttRpcClientTopicGenerationStrategy TopicGenerationStrategy { get; set; } = new DefaultMqttRpcClientTopicGenerationStrategy();
+    }
+}
@@ -0,0 +1,25 @@
+using MQTTnet.Extensions.Rpc.Options.TopicGeneration;
+using System;
+
+namespace MQTTnet.Extensions.Rpc.Options
+{
+    public class MqttRpcClientOptionsBuilder
+    {
+        IMqttRpcClientTopicGenerationStrategy _topicGenerationStrategy = new DefaultMqttRpcClientTopicGenerationStrategy();
+
+        public MqttRpcClientOptionsBuilder WithTopicGenerationStrategy(IMqttRpcClientTopicGenerationStrategy value)
+        {
+            _topicGenerationStrategy = value ?? throw new ArgumentNullException(nameof(value));
+
+            return this;
+        }
+
+        public IMqttRpcClientOptions Build()
+        {
+            return new MqttRpcClientOptions
+            {
+                TopicGenerationStrategy = _topicGenerationStrategy
+            };
+        }
+    }
+}
@@ -0,0 +1,9 @@
+namespace MQTTnet.Extensions.Rpc.Options
+{
+    public class MqttRpcTopicPair
+    {
+        public string RequestTopic { get; set; }
+
+        public string ResponseTopic { get; set; }
+    }
+}
@@ -0,0 +1,19 @@
+using System;
+
+namespace MQTTnet.Extensions.Rpc.Options.TopicGeneration
+{
+    public class DefaultMqttRpcClientTopicGenerationStrategy : IMqttRpcClientTopicGenerationStrategy
+    {
+        public MqttRpcTopicPair CreateRpcTopics(TopicGenerationContext context)
+        {
+            var requestTopic = $"MQTTnet.RPC/{Guid.NewGuid():N}/{context.MethodName}";
+            var responseTopic = requestTopic + "/response";
+
+            return new MqttRpcTopicPair
+            {
+                RequestTopic = requestTopic,
+                ResponseTopic = responseTopic
+            };
+        }
+    }
+}
@@ -0,0 +1,7 @@
+namespace MQTTnet.Extensions.Rpc.Options.TopicGeneration
+{
+    public interface IMqttRpcClientTopicGenerationStrategy
+    {
+        MqttRpcTopicPair CreateRpcTopics(TopicGenerationContext context);
+    }
+}
@@ -0,0 +1,16 @@
+using MQTTnet.Client;
+using MQTTnet.Protocol;
+
+namespace MQTTnet.Extensions.Rpc.Options.TopicGeneration
+{
+    public class TopicGenerationContext
+    {
+        public string MethodName { get; set; }
+
+        public MqttQualityOfServiceLevel QualityOfServiceLevel { get; set; }
+
+        public IMqttClient MqttClient { get; set; }
+
+        public IMqttRpcClientOptions Options { get; set; }
+    }
+}
@@ -1,20 +1,23 @@
 <Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
-    <TargetFrameworks>netstandard1.3;netstandard2.0</TargetFrameworks>
+    <TargetFrameworks>netstandard1.3;netstandard2.0;netstandard2.1</TargetFrameworks>
    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461</TargetFrameworks>
    <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' AND '$(MSBuildRuntimeType)' != 'Core' AND '$(SolutionName)' != 'MQTTnet.noUWP' ">$(TargetFrameworks);uap10.0</TargetFrameworks>
    <Product />
    <Company />
    <Authors />
    <PackageId />
+    <PublishRepositoryUrl>true</PublishRepositoryUrl>
+    <IncludeSymbols>true</IncludeSymbols>
+    <SymbolPackageFormat>snupkg</SymbolPackageFormat>
  </PropertyGroup>

  <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0'">
    <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>
    <NugetTargetMoniker>UAP,Version=v10.0</NugetTargetMoniker>
    <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
-    <TargetPlatformVersion>10.0.17134.0</TargetPlatformVersion>
+    <TargetPlatformVersion>10.0.18362.0</TargetPlatformVersion>
    <TargetPlatformMinVersion>10.0.10240.0</TargetPlatformMinVersion>
    <TargetFrameworkIdentifier>.NETCore</TargetFrameworkIdentifier>
    <TargetFrameworkVersion>v5.0</TargetFrameworkVersion>
@@ -23,6 +26,10 @@
    <LanguageTargets>$(MSBuildExtensionsPath)\Microsoft\WindowsXaml\v$(VisualStudioVersion)\Microsoft.Windows.UI.Xaml.CSharp.targets</LanguageTargets>
  </PropertyGroup>

+  <ItemGroup>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
+  </ItemGroup>
+
  <ItemGroup>
    <PackageReference Include="WebSocket4Net" Version="0.15.2" />
  </ItemGroup>
@@ -8,7 +8,7 @@ namespace MQTTnet.Extensions.WebSocket4Net
        {
            if (mqttFactory == null) throw new ArgumentNullException(nameof(mqttFactory));

-            return mqttFactory.UseClientAdapterFactory(new WebSocket4NetMqttClientAdapterFactory());
+            return mqttFactory.UseClientAdapterFactory(new WebSocket4NetMqttClientAdapterFactory(mqttFactory.DefaultLogger));
        }
    }
 }
@@ -85,7 +85,12 @@ namespace MQTTnet.Extensions.WebSocket4Net
            {
                foreach (var certificate in _webSocketOptions.TlsOptions.Certificates)
                {
+#if WINDOWS_UWP
                    certificates.Add(new X509Certificate(certificate));
+#else
+                    certificates.Add(certificate);
+#endif
+                    
                }
            }

@@ -1,35 +1,41 @@
-using System;
-using MQTTnet.Adapter;
+using MQTTnet.Adapter;
 using MQTTnet.Client.Options;
 using MQTTnet.Diagnostics;
 using MQTTnet.Formatter;
 using MQTTnet.Implementations;
+using System;

 namespace MQTTnet.Extensions.WebSocket4Net
 {
    public class WebSocket4NetMqttClientAdapterFactory : IMqttClientAdapterFactory
    {
-        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetChildLogger logger)
+        readonly IMqttNetLogger _logger;
+
+        public WebSocket4NetMqttClientAdapterFactory(IMqttNetLogger logger)
+        {
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        }
+
+        public IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options)
        {
            if (options == null) throw new ArgumentNullException(nameof(options));
-            if (logger == null) throw new ArgumentNullException(nameof(logger));

            switch (options.ChannelOptions)
            {
                case MqttClientTcpOptions _:
-                {
-                    return new MqttChannelAdapter(new MqttTcpChannel(options), new MqttPacketFormatterAdapter(options.ProtocolVersion), logger);
-                }
+                    {
+                        return new MqttChannelAdapter(new MqttTcpChannel(options), new MqttPacketFormatterAdapter(options.ProtocolVersion), _logger);
+                    }

                case MqttClientWebSocketOptions webSocketOptions:
-                {
-                    return new MqttChannelAdapter(new WebSocket4NetMqttChannel(options, webSocketOptions), new MqttPacketFormatterAdapter(options.ProtocolVersion), logger);
-                }
+                    {
+                        return new MqttChannelAdapter(new WebSocket4NetMqttChannel(options, webSocketOptions), new MqttPacketFormatterAdapter(options.ProtocolVersion), _logger);
+                    }

                default:
-                {
-                    throw new NotSupportedException();
-                }
+                    {
+                        throw new NotSupportedException();
+                    }
            }
        }
    }
@@ -0,0 +1,12 @@
+{
+  "version": 1,
+  "isRoot": true,
+  "tools": {
+    "dotnet-ef": {
+      "version": "3.1.4",
+      "commands": [
+        "dotnet-ef"
+      ]
+    }
+  }
+}
@@ -0,0 +1,35 @@
+using System.IO;
+
+namespace MQTTnet.Server.Configuration
+{
+    public class CertificateSettingsModel
+    {
+        /// <summary>
+        /// Path to certificate.
+        /// </summary>
+        public string Path { get; set; }
+        
+        /// <summary>
+        /// Password of certificate.
+        /// </summary>
+        public string Password { get; set; }
+
+        /// <summary>
+        /// Read certificate file.
+        /// </summary>
+        public byte[] ReadCertificate()
+        {
+            if (string.IsNullOrEmpty(Path) || string.IsNullOrWhiteSpace(Path))
+            {
+                throw new FileNotFoundException("No path set");
+            }
+
+            if (!File.Exists(Path))
+            {
+                throw new FileNotFoundException($"Could not find Certificate in path: {Path}");
+            }
+
+            return File.ReadAllBytes(Path);
+        }
+    }
+}
@@ -9,9 +9,9 @@ namespace MQTTnet.Server.Configuration
    public class TcpEndPointModel
    {
        /// <summary>
-        /// Path to Certificate
+        /// Certificate settings.
        /// </summary>
-        public string CertificatePath { get; set; }
+        public CertificateSettingsModel Certificate { get; set; }

        /// <summary>
        /// Enabled / Disable
@@ -33,25 +33,6 @@ namespace MQTTnet.Server.Configuration
        /// </summary>
        public int Port { get; set; } = 1883;

-        /// <summary>
-        /// Read Certificate file
-        /// </summary>
-        /// <returns></returns>
-        public byte[] ReadCertificate()
-        {
-            if (string.IsNullOrEmpty(CertificatePath) || string.IsNullOrWhiteSpace(CertificatePath))
-            {
-                throw new FileNotFoundException("No path set");
-            }
-
-            if (!File.Exists(CertificatePath))
-            {
-                throw new FileNotFoundException($"Could not find Certificate in path: {CertificatePath}");
-            }
-
-            return File.ReadAllBytes(CertificatePath);
-        }
-
        /// <summary>
        /// Read IPv4
        /// </summary>
@@ -13,7 +13,7 @@ namespace MQTTnet.Server.Controllers
 {
    [Authorize]
    [ApiController]
-    public class ClientsController : ControllerBase
+    public class ClientsController : Controller
    {
        private readonly MqttServerService _mqttServerService;

@@ -0,0 +1,51 @@
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using MQTTnet.Protocol;
+using MQTTnet.Server.Mqtt;
+
+namespace MQTTnet.Server.Controllers
+{
+    [Authorize]
+    [ApiController]
+    public class MessagesController : Controller
+    {
+        private readonly MqttServerService _mqttServerService;
+
+        public MessagesController(MqttServerService mqttServerService)
+        {
+            _mqttServerService = mqttServerService ?? throw new ArgumentNullException(nameof(mqttServerService));
+        }
+
+        [Route("api/v1/messages")]
+        [HttpPost]
+        public async Task<ActionResult> PostMessage(MqttApplicationMessage message)
+        {
+            await _mqttServerService.PublishAsync(message);
+            return Ok();
+        }
+
+        [Route("api/v1/messages/{*topic}")]
+        [HttpPost]
+        public async Task<ActionResult> PostMessage(string topic, int qosLevel = 0)
+        {
+            byte[] payload;
+
+            using (var memoryStream = new MemoryStream())
+            {
+                await HttpContext.Request.Body.CopyToAsync(memoryStream);
+                payload = memoryStream.ToArray();
+            }
+
+            var message = new MqttApplicationMessageBuilder()
+                .WithTopic(topic)
+                .WithPayload(payload)
+                .WithQualityOfServiceLevel((MqttQualityOfServiceLevel)qosLevel)
+                .Build();
+
+            return await PostMessage(message);
+        }
+    }
+}
@@ -12,7 +12,7 @@ namespace MQTTnet.Server.Controllers
 {
    [Authorize]
    [ApiController]
-    public class RetainedApplicationMessagesController : ControllerBase
+    public class RetainedApplicationMessagesController : Controller
    {
        private readonly MqttServerService _mqttServerService;

@@ -0,0 +1,20 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using System.Diagnostics;
+using System.Reflection;
+
+namespace MQTTnet.Server.Controllers
+{
+    [Authorize]
+    [ApiController]
+    public class ServerController : Controller
+    {
+        [Route("api/v1/server/version")]
+        [HttpGet]
+        public ActionResult<string> GetVersion()
+        {
+            var fileVersion = FileVersionInfo.GetVersionInfo(Assembly.GetExecutingAssembly().Location);
+            return fileVersion.ProductVersion.ToString();
+        }
+    }
+}
@@ -13,7 +13,7 @@ namespace MQTTnet.Server.Controllers
 {
    [Authorize]
    [ApiController]
-    public class SessionsController : ControllerBase
+    public class SessionsController : Controller
    {
        private readonly MqttServerService _mqttServerService;

@@ -1,43 +1,43 @@
-using System;
-using MQTTnet.Diagnostics;
+//using MQTTnet.Diagnostics;
+//using System;

-namespace MQTTnet.Server.Logging
-{
-    public class MqttNetChildLoggerWrapper : IMqttNetChildLogger
-    {
-        private readonly MqttNetLoggerWrapper _logger;
-        private readonly string _source;
+//namespace MQTTnet.Server.Logging
+//{
+//    public class MqttNetChildLoggerWrapper : IMqttNetChildLogger
+//    {
+//        private readonly MqttNetLoggerWrapper _logger;
+//        private readonly string _source;

-        public MqttNetChildLoggerWrapper(string source, MqttNetLoggerWrapper logger)
-        {
-            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+//        public MqttNetChildLoggerWrapper(string source, MqttNetLoggerWrapper logger)
+//        {
+//            _logger = logger ?? throw new ArgumentNullException(nameof(logger));

-            _source = source;
-        }
+//            _source = source;
+//        }

-        public IMqttNetChildLogger CreateChildLogger(string source = null)
-        {
-            return _logger.CreateChildLogger(source);
-        }
+//        public IMqttNetLogger CreateChildLogger(string source = null)
+//        {
+//            return _logger.CreateChildLogger(source);
+//        }

-        public void Verbose(string message, params object[] parameters)
-        {
-            _logger.Publish(MqttNetLogLevel.Verbose, _source, message, parameters, null);
-        }
+//        public void Verbose(string message, params object[] parameters)
+//        {
+//            _logger.Publish(MqttNetLogLevel.Verbose, _source, message, parameters, null);
+//        }

-        public void Info(string message, params object[] parameters)
-        {
-            _logger.Publish(MqttNetLogLevel.Info, _source, message, parameters, null);
-        }
+//        public void Info(string message, params object[] parameters)
+//        {
+//            _logger.Publish(MqttNetLogLevel.Info, _source, message, parameters, null);
+//        }

-        public void Warning(Exception exception, string message, params object[] parameters)
-        {
-            _logger.Publish(MqttNetLogLevel.Warning, _source, message, parameters, exception);
-        }
+//        public void Warning(Exception exception, string message, params object[] parameters)
+//        {
+//            _logger.Publish(MqttNetLogLevel.Warning, _source, message, parameters, exception);
+//        }

-        public void Error(Exception exception, string message, params object[] parameters)
-        {
-            _logger.Publish(MqttNetLogLevel.Error, _source, message, parameters, exception);
-        }
-    }
-}
+//        public void Error(Exception exception, string message, params object[] parameters)
+//        {
+//            _logger.Publish(MqttNetLogLevel.Error, _source, message, parameters, exception);
+//        }
+//    }
+//}
@@ -1,13 +1,13 @@
-using System;
-using System.Threading;
-using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging;
 using MQTTnet.Diagnostics;
+using System;
+using System.Threading;

 namespace MQTTnet.Server.Logging
 {
-    public class MqttNetLoggerWrapper : IMqttNetLogger
+    public sealed class MqttNetLoggerWrapper : IMqttNetLogger
    {
-        private readonly ILogger<MqttServer> _logger;
+        readonly ILogger<MqttServer> _logger;

        public MqttNetLoggerWrapper(ILogger<MqttServer> logger)
        {
@@ -16,25 +16,39 @@ namespace MQTTnet.Server.Logging

        public event EventHandler<MqttNetLogMessagePublishedEventArgs> LogMessagePublished;

-        public IMqttNetChildLogger CreateChildLogger(string source = null)
+        public IMqttNetScopedLogger CreateScopedLogger(string source)
        {
-            return new MqttNetChildLoggerWrapper(source, this);
+            return new MqttNetScopedLogger(this, source);
        }

-        public void Publish(MqttNetLogLevel logLevel, string source, string message, object[] parameters, Exception exception)
+        public void Publish(MqttNetLogLevel level, string source, string message, object[] parameters, Exception exception)
        {
-            var convertedLogLevel = ConvertLogLevel(logLevel);
+            var convertedLogLevel = ConvertLogLevel(level);
            _logger.Log(convertedLogLevel, exception, message, parameters);

            var logMessagePublishedEvent = LogMessagePublished;
            if (logMessagePublishedEvent != null)
            {
-                var logMessage = new MqttNetLogMessage(null, DateTime.UtcNow, Thread.CurrentThread.ManagedThreadId, source, logLevel, message, exception);
+                var logMessage = new MqttNetLogMessage
+                {
+                    Timestamp = DateTime.UtcNow,
+                    ThreadId = Thread.CurrentThread.ManagedThreadId,
+                    Source = source,
+                    Level = level,
+                    Message = message,
+                    Exception = exception
+                };
+
                logMessagePublishedEvent.Invoke(this, new MqttNetLogMessagePublishedEventArgs(logMessage));
            }
        }
-        
-        private static LogLevel ConvertLogLevel(MqttNetLogLevel logLevel)
+
+        public void Publish(MqttNetLogLevel logLevel, string message, object[] parameters, Exception exception)
+        {
+            Publish(logLevel, null, message, parameters, exception);
+        }
+
+        static LogLevel ConvertLogLevel(MqttNetLogLevel logLevel)
        {
            switch (logLevel)
            {
@@ -1,26 +1,29 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
-    <TargetFramework>netcoreapp2.2</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
    <AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>
    <AssemblyName>MQTTnet.Server</AssemblyName>
    <RootNamespace>MQTTnet.Server</RootNamespace>
    <GeneratePackageOnBuild>False</GeneratePackageOnBuild>
    <Company />
    <Product>MQTTnet</Product>
-    <Description />
-    <Authors />
+    <Description>Standalone MQTT server with Python scripting backend.</Description>
+    <Authors>The authors of MQTTnet.Server.</Authors>
    <PackageId />
    <SignAssembly>false</SignAssembly>
    <DelaySign>false</DelaySign>
    <LangVersion>latest</LangVersion>
-    <Version>1.0.0</Version>
+    <Version>3.0.11</Version>
    <TypeScriptToolsVersion>3.3</TypeScriptToolsVersion>
  </PropertyGroup>

  <PropertyGroup>
-    <StartupObject></StartupObject>
+    <StartupObject>MQTTnet.Server.Program</StartupObject>
    <UserSecretsId>c564f0de-28b4-45bf-b726-4d665d705653</UserSecretsId>
+    <Copyright>(c) Christian Kratky 2016-2020</Copyright>
+    <PackageProjectUrl>https://github.com/chkr1011/MQTTnet</PackageProjectUrl>
+    <RepositoryUrl>https://github.com/chkr1011/MQTTnet</RepositoryUrl>
  </PropertyGroup>

  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
@@ -29,13 +32,6 @@
    <NoWarn>1701;1702</NoWarn>
  </PropertyGroup>

-  <ItemGroup>
-    <Compile Remove="wwwroot\**" />
-    <Content Remove="wwwroot\**" />
-    <EmbeddedResource Remove="wwwroot\**" />
-    <None Remove="wwwroot\**" />
-  </ItemGroup>
-
  <ItemGroup>
    <Content Update="appsettings.json">
      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
@@ -43,14 +39,12 @@
  </ItemGroup>

  <ItemGroup>
-    <PackageReference Include="IronPython" Version="2.7.9" />
-    <PackageReference Include="IronPython.StdLib" Version="2.7.9" />
-    <PackageReference Include="Microsoft.AspNetCore.App" />
-    <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="2.2.0" PrivateAssets="All" />
-    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.2.0" />
-    <PackageReference Include="Microsoft.AspNetCore.WebSockets" Version="2.2.1" />
-    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerGen" Version="5.0.0-rc2" />
-    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerUI" Version="5.0.0-rc2" />
+    <PackageReference Include="IronPython" Version="2.7.10" />
+    <PackageReference Include="IronPython.StdLib" Version="2.7.10" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.1.5" />
+    <PackageReference Include="MSTest.TestAdapter" Version="2.1.2" />
+    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerGen" Version="5.5.1" />
+    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerUI" Version="5.5.1" />
  </ItemGroup>

  <ItemGroup>
@@ -74,11 +68,19 @@
    <None Update="Web\authorization_handler.py">
      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
    </None>
+    <None Update="Web\wwwroot\Hello.txt">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
+    <None Update="Web\wwwroot\mqtt_Test.html">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
+    <None Update="Web\wwwroot\pahoJS_Test.html">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
  </ItemGroup>

  <ItemGroup>
    <Folder Include="Properties\PublishProfiles\" />
-    <Folder Include="Web\wwwroot\" />
  </ItemGroup>

 </Project>
@@ -22,14 +22,18 @@ namespace MQTTnet.Server.Mqtt
        {
            try
            {
+                // This might be not set when a message was published by the server instead of a client.
+                context.SessionItems.TryGetValue(MqttServerConnectionValidator.WrappedSessionItemsKey, out var sessionItems);
+
                var pythonContext = new PythonDictionary
                {
+                    { "client_id", context.ClientId },
+                    { "session_items", sessionItems },
+                    { "retain", context.ApplicationMessage.Retain },
                    { "accept_publish", context.AcceptPublish },
                    { "close_connection", context.CloseConnection },
-                    { "client_id", context.ClientId },
                    { "topic", context.ApplicationMessage.Topic },
-                    { "qos", (int)context.ApplicationMessage.QualityOfServiceLevel },
-                    { "retain", context.ApplicationMessage.Retain }
+                    { "qos", (int)context.ApplicationMessage.QualityOfServiceLevel }
                };
                
                _pythonScriptHostService.InvokeOptionalFunction("on_intercept_application_message", pythonContext);
@@ -47,4 +51,4 @@ namespace MQTTnet.Server.Mqtt
            return Task.CompletedTask;
        }
    }
-}
+}
@@ -9,6 +9,8 @@ namespace MQTTnet.Server.Mqtt
 {
    public class MqttServerConnectionValidator : IMqttServerConnectionValidator
    {
+        public const string WrappedSessionItemsKey = "WRAPPED_ITEMS";
+
        private readonly PythonScriptHostService _pythonScriptHostService;
        private readonly ILogger _logger;

@@ -22,6 +24,8 @@ namespace MQTTnet.Server.Mqtt
        {
            try
            {
+                var sessionItems = new PythonDictionary();
+
                var pythonContext = new PythonDictionary
                {
                    { "endpoint", context.Endpoint },
@@ -33,6 +37,7 @@ namespace MQTTnet.Server.Mqtt
                    { "clean_session", context.CleanSession},
                    { "authentication_method", context.AuthenticationMethod},
                    { "authentication_data", new Bytes(context.AuthenticationData ?? new byte[0]) },
+                    { "session_items", sessionItems },

                    { "result", PythonConvert.Pythonfy(context.ReasonCode) }
                };
@@ -40,6 +45,8 @@ namespace MQTTnet.Server.Mqtt
                _pythonScriptHostService.InvokeOptionalFunction("on_validate_client_connection", pythonContext);

                context.ReasonCode = PythonConvert.ParseEnum<MqttConnectReasonCode>((string)pythonContext["result"]);
+
+                context.SessionItems[WrappedSessionItemsKey] = sessionItems;
            }
            catch (Exception exception)
            {
@@ -1,11 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Net.WebSockets;
-using System.Security.Authentication;
-using System.Text;
-using System.Threading.Tasks;
-using IronPython.Runtime;
+using IronPython.Runtime;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Logging;
 using MQTTnet.Adapter;
@@ -16,25 +9,33 @@ using MQTTnet.Protocol;
 using MQTTnet.Server.Configuration;
 using MQTTnet.Server.Scripting;
 using MQTTnet.Server.Status;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.WebSockets;
+using System.Security.Authentication;
+using System.Text;
+using System.Threading.Tasks;

 namespace MQTTnet.Server.Mqtt
 {
    public class MqttServerService
    {
-        private readonly ILogger<MqttServerService> _logger;
+        readonly ILogger<MqttServerService> _logger;

-        private readonly MqttSettingsModel _settings;
-        private readonly MqttApplicationMessageInterceptor _mqttApplicationMessageInterceptor;
-        private readonly MqttServerStorage _mqttServerStorage;
-        private readonly MqttClientConnectedHandler _mqttClientConnectedHandler;
-        private readonly MqttClientDisconnectedHandler _mqttClientDisconnectedHandler;
-        private readonly MqttClientSubscribedTopicHandler _mqttClientSubscribedTopicHandler;
-        private readonly MqttClientUnsubscribedTopicHandler _mqttClientUnsubscribedTopicHandler;
-        private readonly MqttServerConnectionValidator _mqttConnectionValidator;
-        private readonly IMqttServer _mqttServer;
-        private readonly MqttSubscriptionInterceptor _mqttSubscriptionInterceptor;
-        private readonly PythonScriptHostService _pythonScriptHostService;
-        private readonly MqttWebSocketServerAdapter _webSocketServerAdapter;
+        readonly MqttSettingsModel _settings;
+        readonly MqttApplicationMessageInterceptor _mqttApplicationMessageInterceptor;
+        readonly MqttServerStorage _mqttServerStorage;
+        readonly MqttClientConnectedHandler _mqttClientConnectedHandler;
+        readonly MqttClientDisconnectedHandler _mqttClientDisconnectedHandler;
+        readonly MqttClientSubscribedTopicHandler _mqttClientSubscribedTopicHandler;
+        readonly MqttClientUnsubscribedTopicHandler _mqttClientUnsubscribedTopicHandler;
+        readonly MqttServerConnectionValidator _mqttConnectionValidator;
+        readonly IMqttServer _mqttServer;
+        readonly MqttSubscriptionInterceptor _mqttSubscriptionInterceptor;
+        readonly MqttUnsubscriptionInterceptor _mqttUnsubscriptionInterceptor;
+        readonly PythonScriptHostService _pythonScriptHostService;
+        readonly MqttWebSocketServerAdapter _webSocketServerAdapter;

        public MqttServerService(
            MqttSettingsModel mqttSettings,
@@ -45,9 +46,10 @@ namespace MQTTnet.Server.Mqtt
            MqttClientUnsubscribedTopicHandler mqttClientUnsubscribedTopicHandler,
            MqttServerConnectionValidator mqttConnectionValidator,
            MqttSubscriptionInterceptor mqttSubscriptionInterceptor,
+            MqttUnsubscriptionInterceptor mqttUnsubscriptionInterceptor,
            MqttApplicationMessageInterceptor mqttApplicationMessageInterceptor,
            MqttServerStorage mqttServerStorage,
-            PythonScriptHostService pythonScriptHostService,            
+            PythonScriptHostService pythonScriptHostService,
            ILogger<MqttServerService> logger)
        {
            _settings = mqttSettings ?? throw new ArgumentNullException(nameof(mqttSettings));
@@ -57,16 +59,17 @@ namespace MQTTnet.Server.Mqtt
            _mqttClientUnsubscribedTopicHandler = mqttClientUnsubscribedTopicHandler ?? throw new ArgumentNullException(nameof(mqttClientUnsubscribedTopicHandler));
            _mqttConnectionValidator = mqttConnectionValidator ?? throw new ArgumentNullException(nameof(mqttConnectionValidator));
            _mqttSubscriptionInterceptor = mqttSubscriptionInterceptor ?? throw new ArgumentNullException(nameof(mqttSubscriptionInterceptor));
+            _mqttUnsubscriptionInterceptor = mqttUnsubscriptionInterceptor ?? throw new ArgumentNullException(nameof(mqttUnsubscriptionInterceptor));
            _mqttApplicationMessageInterceptor = mqttApplicationMessageInterceptor ?? throw new ArgumentNullException(nameof(mqttApplicationMessageInterceptor));
            _mqttServerStorage = mqttServerStorage ?? throw new ArgumentNullException(nameof(mqttServerStorage));
            _pythonScriptHostService = pythonScriptHostService ?? throw new ArgumentNullException(nameof(pythonScriptHostService));
            _logger = logger ?? throw new ArgumentNullException(nameof(logger));

-            _webSocketServerAdapter = new MqttWebSocketServerAdapter(mqttFactory.Logger.CreateChildLogger());
+            _webSocketServerAdapter = new MqttWebSocketServerAdapter(mqttFactory.Logger);

            var adapters = new List<IMqttServerAdapter>
            {
-                new MqttTcpServerAdapter(mqttFactory.Logger.CreateChildLogger())
+                new MqttTcpServerAdapter(mqttFactory.Logger)
                {
                    TreatSocketOpeningErrorAsWarning = true // Opening other ports than for HTTP is not allows in Azure App Services.
                },
@@ -124,7 +127,7 @@ namespace MQTTnet.Server.Mqtt
            return _mqttServer.PublishAsync(applicationMessage);
        }

-        private void Publish(PythonDictionary parameters)
+        void Publish(PythonDictionary parameters)
        {
            try
            {
@@ -170,7 +173,7 @@ namespace MQTTnet.Server.Mqtt
            }
        }

-        private IMqttServerOptions CreateMqttServerOptions()
+        IMqttServerOptions CreateMqttServerOptions()
        {
            var options = new MqttServerOptionsBuilder()
                .WithMaxPendingMessagesPerClient(_settings.MaxPendingMessagesPerClient)
@@ -178,8 +181,9 @@ namespace MQTTnet.Server.Mqtt
                .WithConnectionValidator(_mqttConnectionValidator)
                .WithApplicationMessageInterceptor(_mqttApplicationMessageInterceptor)
                .WithSubscriptionInterceptor(_mqttSubscriptionInterceptor)
+                .WithUnsubscriptionInterceptor(_mqttUnsubscriptionInterceptor)
                .WithStorage(_mqttServerStorage);
-            
+
            // Configure unencrypted connections
            if (_settings.TcpEndPoint.Enabled)
            {
@@ -210,8 +214,22 @@ namespace MQTTnet.Server.Mqtt
            {
                options
                    .WithEncryptedEndpoint()
-                    .WithEncryptionSslProtocol(SslProtocols.Tls12)
-                    .WithEncryptionCertificate(_settings.EncryptedTcpEndPoint.ReadCertificate());
+                    .WithEncryptionSslProtocol(SslProtocols.Tls12);
+
+                if (!string.IsNullOrEmpty(_settings.EncryptedTcpEndPoint?.Certificate?.Path))
+                {
+                    IMqttServerCertificateCredentials certificateCredentials = null;
+
+                    if (!string.IsNullOrEmpty(_settings.EncryptedTcpEndPoint?.Certificate?.Password))
+                    {
+                        certificateCredentials = new MqttServerCertificateCredentials
+                        {
+                            Password = _settings.EncryptedTcpEndPoint.Certificate.Password
+                        };
+                    }
+
+                    options.WithEncryptionCertificate(_settings.EncryptedTcpEndPoint.Certificate.ReadCertificate(), certificateCredentials);
+                }

                if (_settings.EncryptedTcpEndPoint.TryReadIPv4(out var address4))
                {
@@ -21,14 +21,16 @@ namespace MQTTnet.Server.Mqtt
        {
            try
            {
+                var sessionItems = (PythonDictionary)context.SessionItems[MqttServerConnectionValidator.WrappedSessionItemsKey];
+
                var pythonContext = new PythonDictionary
                {
-                    { "accept_subscription", context.AcceptSubscription },
-                    { "close_connection", context.CloseConnection },
-
                    { "client_id", context.ClientId },
+                    { "session_items", sessionItems },
                    { "topic", context.TopicFilter.Topic },
-                    { "qos", (int)context.TopicFilter.QualityOfServiceLevel }
+                    { "qos", (int)context.TopicFilter.QualityOfServiceLevel },
+                    { "accept_subscription", context.AcceptSubscription },
+                    { "close_connection", context.CloseConnection }
                };

                _pythonScriptHostService.InvokeOptionalFunction("on_intercept_subscription", pythonContext);
@@ -0,0 +1,48 @@
+using System;
+using System.Threading.Tasks;
+using IronPython.Runtime;
+using Microsoft.Extensions.Logging;
+using MQTTnet.Server.Scripting;
+
+namespace MQTTnet.Server.Mqtt
+{
+    public class MqttUnsubscriptionInterceptor : IMqttServerUnsubscriptionInterceptor
+    {
+        private readonly PythonScriptHostService _pythonScriptHostService;
+        private readonly ILogger _logger;
+
+        public MqttUnsubscriptionInterceptor(PythonScriptHostService pythonScriptHostService, ILogger<MqttUnsubscriptionInterceptor> logger)
+        {
+            _pythonScriptHostService = pythonScriptHostService ?? throw new ArgumentNullException(nameof(pythonScriptHostService));
+            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        }
+
+        public Task InterceptUnsubscriptionAsync(MqttUnsubscriptionInterceptorContext context)
+        {
+            try
+            {
+                var sessionItems = (PythonDictionary)context.SessionItems[MqttServerConnectionValidator.WrappedSessionItemsKey];
+
+                var pythonContext = new PythonDictionary
+                {
+                    { "client_id", context.ClientId },
+                    { "session_items", sessionItems },
+                    { "topic", context.Topic },
+                    { "accept_unsubscription", context.AcceptUnsubscription },
+                    { "close_connection", context.CloseConnection }
+                };
+
+                _pythonScriptHostService.InvokeOptionalFunction("on_intercept_unsubscription", pythonContext);
+
+                context.AcceptUnsubscription = (bool)pythonContext["accept_unsubscription"];
+                context.CloseConnection = (bool)pythonContext["close_connection"];
+            }
+            catch (Exception exception)
+            {
+                _logger.LogError(exception, "Error while intercepting unsubscription.");
+            }
+
+            return Task.CompletedTask;
+        }
+    }
+}
@@ -1,8 +1,10 @@
-using System;
-using System.Reflection;
-using Microsoft.AspNetCore;
-using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Hosting;
 using MQTTnet.Server.Web;
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Reflection;

 namespace MQTTnet.Server
 {
@@ -14,7 +16,15 @@ namespace MQTTnet.Server
            {
                PrintLogo();

-                WebHost.CreateDefaultBuilder(args).UseStartup<Startup>().Build().Run();
+                Host.CreateDefaultBuilder(args)
+                    .ConfigureWebHostDefaults(webBuilder =>
+                    {
+                        webBuilder.ConfigureKestrel(serverOptions =>
+                        {
+                        })
+                        .UseWebRoot(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Web", "wwwroot"))
+                        .UseStartup<Startup>();
+                    }).Build().Run();

                return 0;
            }
@@ -25,7 +35,7 @@ namespace MQTTnet.Server
            }
        }

-        private static void PrintLogo()
+        static void PrintLogo()
        {
            Console.ResetColor();
            Console.ForegroundColor = ConsoleColor.Red;
@@ -46,14 +56,15 @@ namespace MQTTnet.Server
            Console.WriteLine();
            Console.ForegroundColor = ConsoleColor.White;
            Console.WriteLine("The official MQTT server implementation of MQTTnet");
-            Console.WriteLine("Copyright (c) 2017-2019 The MQTTnet Team");
-
-            Console.ForegroundColor = ConsoleColor.Blue;
+            Console.WriteLine("Copyright (c) 2017-2020 The MQTTnet Team");
            Console.WriteLine(@"https://github.com/chkr1011/MQTTnet");

            Console.ForegroundColor = ConsoleColor.White;
+
+            var fileVersion = FileVersionInfo.GetVersionInfo(Assembly.GetExecutingAssembly().Location);
+
            Console.WriteLine($@"
-Version:    {Assembly.GetExecutingAssembly().GetCustomAttribute<AssemblyInformationalVersionAttribute>().InformationalVersion}
+Version:    {fileVersion.ProductVersion}
 License:    MIT (read LICENSE file)
 Sponsoring: https://opencollective.com/mqttnet
 Support:    https://github.com/chkr1011/MQTTnet/issues
@@ -1,14 +1,14 @@
-using System;
+using Microsoft.Extensions.Logging;
+using System;
 using System.Collections.Generic;
-using Microsoft.Extensions.Logging;

 namespace MQTTnet.Server.Scripting.DataSharing
 {
    public class DataSharingService
    {
-        private readonly Dictionary<string, object> _storage = new Dictionary<string, object>();
-        private readonly PythonScriptHostService _pythonScriptHostService;
-        private readonly ILogger<DataSharingService> _logger;
+        readonly Dictionary<string, object> _storage = new Dictionary<string, object>();
+        readonly PythonScriptHostService _pythonScriptHostService;
+        readonly ILogger<DataSharingService> _logger;

        public DataSharingService(PythonScriptHostService pythonScriptHostService, ILogger<DataSharingService> logger)
        {
@@ -1,14 +1,14 @@
-using System;
+using Microsoft.Extensions.Logging;
+using System;
 using System.IO;
 using System.Text;
-using Microsoft.Extensions.Logging;

 namespace MQTTnet.Server.Scripting
 {
    public class PythonIOStream : Stream
    {
-        private readonly ILogger _logger;
-        private readonly Encoding _encoder = Encoding.UTF8;
+        readonly ILogger _logger;
+        readonly Encoding _encoder = Encoding.UTF8;

        public PythonIOStream(ILogger<PythonIOStream> logger)
        {
@@ -1,4 +1,8 @@
-using System;
+using Microsoft.Extensions.Logging;
+using Microsoft.Scripting;
+using Microsoft.Scripting.Hosting;
+using MQTTnet.Server.Configuration;
+using System;
 using System.Collections.Generic;
 using System.Dynamic;
 using System.IO;
@@ -6,22 +10,18 @@ using System.Linq;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.Extensions.Logging;
-using Microsoft.Scripting;
-using Microsoft.Scripting.Hosting;
-using MQTTnet.Server.Configuration;

 namespace MQTTnet.Server.Scripting
 {
    public class PythonScriptHostService
    {
-        private readonly IDictionary<string, object> _proxyObjects = new ExpandoObject();
-        private readonly List<PythonScriptInstance> _scriptInstances = new List<PythonScriptInstance>();
-        private readonly string _scriptsPath;
-        private readonly ScriptingSettingsModel _scriptingSettings;
-        private readonly ILogger<PythonScriptHostService> _logger;
-        private readonly ScriptEngine _scriptEngine;
-        
+        readonly IDictionary<string, object> _proxyObjects = new ExpandoObject();
+        readonly List<PythonScriptInstance> _scriptInstances = new List<PythonScriptInstance>();
+        readonly string _scriptsPath;
+        readonly ScriptingSettingsModel _scriptingSettings;
+        readonly ILogger<PythonScriptHostService> _logger;
+        readonly ScriptEngine _scriptEngine;
+
        public PythonScriptHostService(ScriptingSettingsModel scriptingSettings, PythonIOStream pythonIOStream, ILogger<PythonScriptHostService> logger)
        {
            _scriptingSettings = scriptingSettings ?? throw new ArgumentNullException(nameof(scriptingSettings));
@@ -139,7 +139,7 @@ namespace MQTTnet.Server.Scripting
            }
        }

-        private async Task TryInitializeScriptAsync(string path)
+        async Task TryInitializeScriptAsync(string path)
        {
            var uid = new FileInfo(path).Name.Replace(".py", string.Empty, StringComparison.OrdinalIgnoreCase);

@@ -155,7 +155,7 @@ namespace MQTTnet.Server.Scripting
                {
                    _scriptInstances.Add(scriptInstance);
                }
-                
+
                _logger.LogInformation($"Initialized script '{uid}'.");
            }
            catch (Exception exception)
@@ -164,7 +164,7 @@ namespace MQTTnet.Server.Scripting
            }
        }

-        private PythonScriptInstance CreateScriptInstance(string uid, string path, string code)
+        PythonScriptInstance CreateScriptInstance(string uid, string path, string code)
        {
            var scriptScope = _scriptEngine.CreateScope();

@@ -173,11 +173,11 @@ namespace MQTTnet.Server.Scripting

            scriptScope.SetVariable("mqtt_net_server", _proxyObjects);
            compiledCode.Execute(scriptScope);
-            
+
            return new PythonScriptInstance(uid, path, scriptScope);
        }

-        private void AddSearchPaths(ScriptEngine scriptEngine)
+        void AddSearchPaths(ScriptEngine scriptEngine)
        {
            if (_scriptingSettings.IncludePaths?.Any() != true)
            {
@@ -1,12 +1,12 @@
-using System;
-using IronPython.Runtime;
+using IronPython.Runtime;
 using Microsoft.Scripting.Hosting;
+using System;

 namespace MQTTnet.Server.Scripting
 {
    public class PythonScriptInstance
    {
-        private readonly ScriptScope _scriptScope;
+        readonly ScriptScope _scriptScope;

        public PythonScriptInstance(string uid, string path, ScriptScope scriptScope)
        {
@@ -1,22 +1,23 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Net;
-using Microsoft.AspNetCore.Authentication;
+using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Net.Http.Headers;
 using Microsoft.OpenApi.Models;
 using Microsoft.Scripting.Utils;
+using MQTTnet.AspNetCore;
 using MQTTnet.Server.Configuration;
 using MQTTnet.Server.Logging;
 using MQTTnet.Server.Mqtt;
 using MQTTnet.Server.Scripting;
 using MQTTnet.Server.Scripting.DataSharing;
+using Newtonsoft.Json.Converters;
 using Swashbuckle.AspNetCore.SwaggerUI;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;

 namespace MQTTnet.Server.Web
 {
@@ -35,33 +36,28 @@ namespace MQTTnet.Server.Web

        public void Configure(
            IApplicationBuilder application,
-            IHostingEnvironment environment,
            MqttServerService mqttServerService,
            PythonScriptHostService pythonScriptHostService,
            DataSharingService dataSharingService,
            MqttSettingsModel mqttSettings)
        {
-            if (environment.IsDevelopment())
-            {
-                application.UseDeveloperExceptionPage();
-            }
-            else
-            {
-                application.UseHsts();
-            }
+            application.UseDefaultFiles();
+            application.UseStaticFiles();

+            application.UseHsts();
+            application.UseRouting();
            application.UseCors(x => x
                .AllowAnyOrigin()
                .AllowAnyMethod()
-                .AllowAnyHeader()
-                .AllowCredentials());
+                .AllowAnyHeader());

            application.UseAuthentication();
-
-            application.UseStaticFiles();
-
-            application.UseHttpsRedirection();
-            application.UseMvc();
+            application.UseAuthorization();
+     
+            application.UseEndpoints(endpoints =>
+            {
+                endpoints.MapControllers();
+            });

            ConfigureWebSocketEndpoint(application, mqttServerService, mqttSettings);

@@ -87,11 +83,13 @@ namespace MQTTnet.Server.Web
        {
            services.AddCors();

+            services.AddControllers();
+
            services.AddMvc()
-                .SetCompatibilityVersion(CompatibilityVersion.Version_2_2)
-                .AddJsonOptions(options =>
+                .SetCompatibilityVersion(CompatibilityVersion.Version_3_0)
+                .AddNewtonsoftJson(o =>
                {
-                    options.SerializerSettings.Converters.Add(new Newtonsoft.Json.Converters.StringEnumConverter());
+                    o.SerializerSettings.Converters.Add(new StringEnumConverter());
                });

            ReadMqttSettings(services);
@@ -111,12 +109,11 @@ namespace MQTTnet.Server.Web
            services.AddSingleton<MqttClientUnsubscribedTopicHandler>();
            services.AddSingleton<MqttServerConnectionValidator>();
            services.AddSingleton<MqttSubscriptionInterceptor>();
+            services.AddSingleton<MqttUnsubscriptionInterceptor>();
            services.AddSingleton<MqttApplicationMessageInterceptor>();

            services.AddSwaggerGen(c =>
            {
-                c.DescribeAllEnumsAsStrings();
-                
                var securityScheme = new OpenApiSecurityScheme
                {
                    Scheme = "Basic",
@@ -156,7 +153,7 @@ namespace MQTTnet.Server.Web
                .AddCookie();
        }

-        private void ReadMqttSettings(IServiceCollection services)
+        void ReadMqttSettings(IServiceCollection services)
        {
            var mqttSettings = new MqttSettingsModel();
            Configuration.Bind("MQTT", mqttSettings);
@@ -167,7 +164,7 @@ namespace MQTTnet.Server.Web
            services.AddSingleton(scriptingSettings);
        }

-        private static void ConfigureWebSocketEndpoint(
+        static void ConfigureWebSocketEndpoint(
            IApplicationBuilder application,
            MqttServerService mqttServerService,
            MqttSettingsModel mqttSettings)
@@ -201,7 +198,13 @@ namespace MQTTnet.Server.Web
                {
                    if (context.WebSockets.IsWebSocketRequest)
                    {
-                        using (var webSocket = await context.WebSockets.AcceptWebSocketAsync().ConfigureAwait(false))
+                        string subProtocol = null;
+                        if (context.Request.Headers.TryGetValue("Sec-WebSocket-Protocol", out var requestedSubProtocolValues))
+                        {
+                            subProtocol = MqttSubProtocolSelector.SelectSubProtocol(requestedSubProtocolValues);
+                        }
+
+                        using (var webSocket = await context.WebSockets.AcceptWebSocketAsync(subProtocol).ConfigureAwait(false))
                        {
                            await mqttServerService.RunWebSocketConnectionAsync(webSocket, context).ConfigureAwait(false);
                        }
@@ -0,0 +1 @@
+World
@@ -0,0 +1,33 @@
+<html>
+
+<head>
+    <title>MQTT JS Example</title>
+
+    <script src="https://cdn.jsdelivr.net/npm/mqtt@4.0.1/dist/mqtt.min.js" type="text/javascript"></script>
+
+    <script type="text/javascript">
+        var client = mqtt.connect('ws://localhost:80/mqtt')
+
+        client.on('connect', function () {
+            client.subscribe('mqtt_subscription', function (err) {
+                console.log("Subscribed");
+            })
+        })
+
+        client.on('message', function (topic, message) {
+            console.log(topic);
+            console.log(message.toString())
+        })
+
+        function buttonClick() {
+            client.publish("MQTT_JS_TOPIC", "payload");
+        }
+    </script>
+
+</head>
+
+<body>
+    <button onclick="buttonClick()">Publish</button>
+</body>
+
+</html>
@@ -0,0 +1,41 @@
+<html>
+
+<head>
+    <title>paho JS Example</title>
+
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/paho-mqtt/1.0.1/mqttws31.js" type="text/javascript"></script>
+
+    <script type="text/javascript">
+        var mqttClient = new Paho.MQTT.Client("localhost", 80, "/mqtt", "pahoJS_client");
+        mqttClient.onConnectionLost = onConnectionLost;
+        mqttClient.onMessageArrived = onMessageArrived;
+        mqttClient.connect({ onSuccess: onConnect });
+
+        function onConnect() {
+            console.log("MQTT client connected");
+            mqttClient.subscribe("pahoJS_subscription");
+        }
+
+        function onConnectionLost(responseObject) {
+            if (responseObject.errorCode !== 0) {
+                console.log("onConnectionLost:" + responseObject.errorMessage);
+            }
+        }
+
+        function onMessageArrived(message) {
+            console.log("onMessageArrived:" + message.payloadString);
+        }
+        function buttonClick() {
+            message = new Paho.MQTT.Message("Hello");
+            message.destinationName = "pahoJS_topic";
+            mqttClient.send(message);
+        }
+    </script>
+
+</head>
+
+<body>
+    <button onclick="buttonClick()">Publish</button>
+</body>
+
+</html>
@@ -27,7 +27,10 @@
            "IPv4": "*",
            "IPv6": "*",
            "Port": 8883,
-            "CertificatePath": "/absolute/path/to/pfx"
+            "Certificate": {
+                "Path": "/absolute/path/to/pfx",
+                "Password": ""
+            }
        },
        "WebSocketEndPoint": {
            "Enabled": true,
@@ -49,11 +52,7 @@
    },
    "Scripting": {
        "ScriptsPath": "Scripts",
-        "IncludePaths": [
-            "Lib",
-            "/usr/lib/python2.7",
-            "C:\\Python27\\Lib"
-        ]
+        "IncludePaths": []
    },
    "Logging": {
        "LogLevel": {
@@ -63,4 +62,4 @@
        }
    },
    "AllowedHosts": "*"
-}
+}
@@ -1,12 +0,0 @@
-{
-  "version": "1.0.0",
-  "name": "mqtt.test",
-  "private": true,
-  "devDependencies": {},
-  "dependencies": {
-    "@types/node": "^8.0.46",
-    "mqtt": "^2.15.1",
-    "systemjs": "^0.20.19",
-    "typescript": "^2.3.4"
-  }
-}
@@ -1,10 +1,9 @@
 using MQTTnet.Client.Options;
-using MQTTnet.Diagnostics;

 namespace MQTTnet.Adapter
 {
    public interface IMqttClientAdapterFactory
    {
-        IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options, IMqttNetChildLogger logger);
+        IMqttChannelAdapter CreateClientAdapter(IMqttClientOptions options);
    }
 }
@@ -1,3 +1,9 @@
+using MQTTnet.Channel;
+using MQTTnet.Diagnostics;
+using MQTTnet.Exceptions;
+using MQTTnet.Formatter;
+using MQTTnet.Internal;
+using MQTTnet.Packets;
 using System;
 using System.IO;
 using System.Net.Sockets;
@@ -5,34 +11,26 @@ using System.Runtime.InteropServices;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
-using MQTTnet.Channel;
-using MQTTnet.Diagnostics;
-using MQTTnet.Exceptions;
-using MQTTnet.Formatter;
-using MQTTnet.Internal;
-using MQTTnet.Packets;

 namespace MQTTnet.Adapter
 {
-    public class MqttChannelAdapter : IMqttChannelAdapter
+    public sealed class MqttChannelAdapter : Disposable, IMqttChannelAdapter
    {
-        private const uint ErrorOperationAborted = 0x800703E3;
-        private const int ReadBufferSize = 4096;  // TODO: Move buffer size to config
+        const uint ErrorOperationAborted = 0x800703E3;
+        const int ReadBufferSize = 4096;

-        private readonly SemaphoreSlim _writerSemaphore = new SemaphoreSlim(1, 1);
+        readonly IMqttNetScopedLogger _logger;
+        readonly IMqttChannel _channel;
+        readonly MqttPacketReader _packetReader;

-        private readonly IMqttNetChildLogger _logger;
-        private readonly IMqttChannel _channel;
-        private readonly MqttPacketReader _packetReader;
+        readonly byte[] _fixedHeaderBuffer = new byte[2];

-        private readonly byte[] _fixedHeaderBuffer = new byte[2];
+        readonly AsyncLock _syncRoot = new AsyncLock();

-        private bool _isDisposed;
+        long _bytesReceived;
+        long _bytesSent;

-        private long _bytesReceived;
-        private long _bytesSent;
-
-        public MqttChannelAdapter(IMqttChannel channel, MqttPacketFormatterAdapter packetFormatterAdapter, IMqttNetChildLogger logger)
+        public MqttChannelAdapter(IMqttChannel channel, MqttPacketFormatterAdapter packetFormatterAdapter, IMqttNetLogger logger)
        {
            if (logger == null) throw new ArgumentNullException(nameof(logger));

@@ -41,7 +39,7 @@ namespace MQTTnet.Adapter

            _packetReader = new MqttPacketReader(_channel);

-            _logger = logger.CreateChildLogger(nameof(MqttChannelAdapter));
+            _logger = logger.CreateScopedLogger(nameof(MqttChannelAdapter));
        }

        public string Endpoint => _channel.Endpoint;
@@ -57,9 +55,10 @@ namespace MQTTnet.Adapter

        public Action ReadingPacketStartedCallback { get; set; }
        public Action ReadingPacketCompletedCallback { get; set; }
-            
+
        public async Task ConnectAsync(TimeSpan timeout, CancellationToken cancellationToken)
        {
+            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();

            try
@@ -86,6 +85,7 @@ namespace MQTTnet.Adapter

        public async Task DisconnectAsync(TimeSpan timeout, CancellationToken cancellationToken)
        {
+            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();

            try
@@ -113,44 +113,58 @@ namespace MQTTnet.Adapter

        public async Task SendPacketAsync(MqttBasePacket packet, TimeSpan timeout, CancellationToken cancellationToken)
        {
-            await _writerSemaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
+            cancellationToken.ThrowIfCancellationRequested();
+            ThrowIfDisposed();
+
            try
            {
-                var packetData = PacketFormatterAdapter.Encode(packet);
-
-                if (timeout == TimeSpan.Zero)
+                using (await _syncRoot.WaitAsync(cancellationToken).ConfigureAwait(false))
                {
-                    await _channel.WriteAsync(packetData.Array, packetData.Offset, packetData.Count, cancellationToken).ConfigureAwait(false);
+                    // Check for cancellation here again because "WaitAsync" might take some time.
+                    cancellationToken.ThrowIfCancellationRequested();
+
+                    try
+                    {
+                        var packetData = PacketFormatterAdapter.Encode(packet);
+
+                        if (timeout == TimeSpan.Zero)
+                        {
+                            await _channel.WriteAsync(packetData.Array, packetData.Offset, packetData.Count, cancellationToken).ConfigureAwait(false);
+                        }
+                        else
+                        {
+                            await MqttTaskTimeout.WaitAsync(
+                                t => _channel.WriteAsync(packetData.Array, packetData.Offset, packetData.Count, t), timeout, cancellationToken).ConfigureAwait(false);
+                        }
+
+                        Interlocked.Add(ref _bytesReceived, packetData.Count);
+
+                        _logger.Verbose("TX ({0} bytes) >>> {1}", packetData.Count, packet);
+                    }
+                    catch (Exception exception)
+                    {
+                        if (IsWrappedException(exception))
+                        {
+                            throw;
+                        }
+
+                        WrapException(exception);
+                    }
+                    finally
+                    {
+                        PacketFormatterAdapter.FreeBuffer();
+                    }
                }
-                else
-                {
-                    await MqttTaskTimeout.WaitAsync(
-                        t => _channel.WriteAsync(packetData.Array, packetData.Offset, packetData.Count, t), timeout, cancellationToken).ConfigureAwait(false);
-                }
-
-                Interlocked.Add(ref _bytesReceived, packetData.Count);
-
-                PacketFormatterAdapter.FreeBuffer();
-
-                _logger.Verbose("TX ({0} bytes) >>> {1}", packetData.Count, packet);
            }
-            catch (Exception exception)
+            catch (ObjectDisposedException)
            {
-                if (IsWrappedException(exception))
-                {
-                    throw;
-                }
-
-                WrapException(exception);
-            }
-            finally
-            {
-                _writerSemaphore.Release();
+                throw new OperationCanceledException();
            }
        }

        public async Task<MqttBasePacket> ReceivePacketAsync(TimeSpan timeout, CancellationToken cancellationToken)
        {
+            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();

            try
@@ -190,6 +204,9 @@ namespace MQTTnet.Adapter
            catch (OperationCanceledException)
            {
            }
+            catch (ObjectDisposedException)
+            {
+            }
            catch (Exception exception)
            {
                if (IsWrappedException(exception))
@@ -209,7 +226,18 @@ namespace MQTTnet.Adapter
            Interlocked.Exchange(ref _bytesSent, 0L);
        }

-        private async Task<ReceivedMqttPacket> ReceiveAsync(CancellationToken cancellationToken)
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                _channel.Dispose();
+                _syncRoot.Dispose();
+            }
+
+            base.Dispose(disposing);
+        }
+
+        async Task<ReceivedMqttPacket> ReceiveAsync(CancellationToken cancellationToken)
        {
            var readFixedHeaderResult = await _packetReader.ReadFixedHeaderAsync(_fixedHeaderBuffer, cancellationToken).ConfigureAwait(false);

@@ -269,29 +297,14 @@ namespace MQTTnet.Adapter
            }
        }

-        public void Dispose()
-        {
-            _isDisposed = true;
-
-            _channel?.Dispose();
-        }
-
-        private void ThrowIfDisposed()
-        {
-            if (_isDisposed)
-            {
-                throw new ObjectDisposedException(nameof(MqttChannelAdapter));
-            }
-        }
-
-        private static bool IsWrappedException(Exception exception)
+        static bool IsWrappedException(Exception exception)
        {
            return exception is OperationCanceledException ||
                   exception is MqttCommunicationTimedOutException ||
                   exception is MqttCommunicationException;
        }

-        private static void WrapException(Exception exception)
+        static void WrapException(Exception exception)
        {
            if (exception is IOException && exception.InnerException is SocketException innerException)
            {
@@ -5,12 +5,13 @@ namespace MQTTnet.Adapter
 {
    public class MqttConnectingFailedException : MqttCommunicationException
    {
-        public MqttConnectingFailedException(MqttClientConnectResultCode resultCode)
-            : base($"Connecting with MQTT server failed ({resultCode.ToString()}).")
+        public MqttConnectingFailedException(MqttClientAuthenticateResult result)
+            : base($"Connecting with MQTT server failed ({result.ResultCode.ToString()}).")
        {
-            ResultCode = resultCode;
+            Result = result;
        }

-        public MqttClientConnectResultCode ResultCode { get; }
+        public MqttClientAuthenticateResult Result { get; }
+        public MqttClientConnectResultCode ResultCode => Result.ResultCode;
    }
 }
@@ -0,0 +1,28 @@
+using System;
+using System.Security.Cryptography.X509Certificates;
+
+namespace MQTTnet.Certificates
+{
+    public class BlobCertificateProvider : ICertificateProvider
+    {
+        public BlobCertificateProvider(byte[] blob)
+        {
+            Blob = blob ?? throw new ArgumentNullException(nameof(blob));
+        }
+
+        public byte[] Blob { get; }
+
+        public string Password { get; set; }
+
+        public X509Certificate2 GetCertificate()
+        {
+            if (string.IsNullOrEmpty(Password))
+            {
+                // Use a different overload when no password is specified. Otherwise the constructor will fail.
+                return new X509Certificate2(Blob);
+            }
+
+            return new X509Certificate2(Blob, Password);
+        }
+    }
+}
@@ -0,0 +1,9 @@
+using System.Security.Cryptography.X509Certificates;
+
+namespace MQTTnet.Certificates
+{
+    public interface ICertificateProvider
+    {
+        X509Certificate2 GetCertificate();
+    }
+}
@@ -0,0 +1,22 @@
+#if !WINDOWS_UWP
+using System;
+using System.Security.Cryptography.X509Certificates;
+
+namespace MQTTnet.Certificates
+{
+    public class X509CertificateProvider : ICertificateProvider
+    {
+        readonly X509Certificate2 _certificate;
+
+        public X509CertificateProvider(X509Certificate2 certificate)
+        {
+            _certificate = certificate ?? throw new ArgumentNullException(nameof(certificate));
+        }
+
+        public X509Certificate2 GetCertificate()
+        {
+            return _certificate;
+        }
+    }
+}
+#endif
@@ -3,6 +3,34 @@
    public enum MqttClientDisconnectReason
    {
        NormalDisconnection = 0,
-
+        DisconnectWithWillMessage = 4,
+        UnspecifiedError = 128,
+        MalformedPacket = 129,
+        ProtocolError = 130,
+        ImplementationSpecificError = 131,
+        NotAuthorized = 135,
+        ServerBusy = 137,
+        ServerShuttingDown = 139,
+        BadAuthenticationMethod = 140,
+        KeepaliveTimeout = 141,
+        SessionTakenOver = 142,
+        TopicFilterInvalid = 143,
+        TopicNameInvalid = 144,
+        ReceiveMaximumExceeded = 147,
+        TopicAliasInvalid = 148,
+        PacketTooLarge = 149,
+        MessageRateTooHigh = 150,
+        QuotaExceeded = 151,
+        AdministrativeAction = 152,
+        PayloadFormatInvalid = 153,
+        RetainNotSupported = 154,
+        QosNotSupported = 155,
+        UseAnotherServer = 156,
+        ServerMoved = 157,
+        SharedSubscriptionsNotSupported = 158,
+        ConnectionRateExceeded = 159,
+        MaximumConnectTime = 160,
+        SubscriptionIdentifiersNotSupported = 161,
+        WildcardSubscriptionsNotSupported = 162
    }
 }
@@ -5,11 +5,12 @@ namespace MQTTnet.Client.Disconnecting
 {
    public class MqttClientDisconnectedEventArgs : EventArgs
    {
-        public MqttClientDisconnectedEventArgs(bool clientWasConnected, Exception exception, MqttClientAuthenticateResult authenticateResult)
+        public MqttClientDisconnectedEventArgs(bool clientWasConnected, Exception exception, MqttClientAuthenticateResult authenticateResult, MqttClientDisconnectReason reasonCode)
        {
            ClientWasConnected = clientWasConnected;
            Exception = exception;
            AuthenticateResult = authenticateResult;
+            ReasonCode = reasonCode;
        }

        public bool ClientWasConnected { get; }
@@ -17,5 +18,7 @@ namespace MQTTnet.Client.Disconnecting
        public Exception Exception { get; }

        public MqttClientAuthenticateResult AuthenticateResult { get; }
+
+        public MqttClientDisconnectReason ReasonCode { get; set; } = MqttClientDisconnectReason.NormalDisconnection;
    }
 }
@@ -1,12 +1,12 @@
-using System;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Client.Connecting;
+using MQTTnet.Client.Connecting;
 using MQTTnet.Client.Disconnecting;
 using MQTTnet.Client.ExtendedAuthenticationExchange;
 using MQTTnet.Client.Options;
 using MQTTnet.Client.Subscribing;
 using MQTTnet.Client.Unsubscribing;
+using System;
+using System.Threading;
+using System.Threading.Tasks;

 namespace MQTTnet.Client
 {
@@ -16,11 +16,12 @@ namespace MQTTnet.Client
        IMqttClientOptions Options { get; }

        IMqttClientConnectedHandler ConnectedHandler { get; set; }
-        
+
        IMqttClientDisconnectedHandler DisconnectedHandler { get; set; }
-        
+
        Task<MqttClientAuthenticateResult> ConnectAsync(IMqttClientOptions options, CancellationToken cancellationToken);
        Task DisconnectAsync(MqttClientDisconnectOptions options, CancellationToken cancellationToken);
+        Task PingAsync(CancellationToken cancellationToken);

        Task SendExtendedAuthenticationExchangeDataAsync(MqttExtendedAuthenticationExchangeData data, CancellationToken cancellationToken);
        Task<MqttClientSubscribeResult> SubscribeAsync(MqttClientSubscribeOptions options, CancellationToken cancellationToken);
@@ -1,5 +1,7 @@
-using MQTTnet.Adapter;
+using System;
+using MQTTnet.Adapter;
 using MQTTnet.Diagnostics;
+using MQTTnet.LowLevelClient;

 namespace MQTTnet.Client
 {
@@ -7,6 +9,14 @@ namespace MQTTnet.Client
    {
        IMqttFactory UseClientAdapterFactory(IMqttClientAdapterFactory clientAdapterFactory);

+        ILowLevelMqttClient CreateLowLevelMqttClient();
+
+        ILowLevelMqttClient CreateLowLevelMqttClient(IMqttNetLogger logger);
+
+        ILowLevelMqttClient CreateLowLevelMqttClient(IMqttClientAdapterFactory clientAdapterFactory);
+
+        ILowLevelMqttClient CreateLowLevelMqttClient(IMqttNetLogger logger, IMqttClientAdapterFactory clientAdapterFactory);
+
        IMqttClient CreateMqttClient();

        IMqttClient CreateMqttClient(IMqttNetLogger logger);
@@ -1,7 +1,3 @@
-using System;
-using System.Diagnostics;
-using System.Threading;
-using System.Threading.Tasks;
 using MQTTnet.Adapter;
 using MQTTnet.Client.Connecting;
 using MQTTnet.Client.Disconnecting;
@@ -17,33 +13,42 @@ using MQTTnet.Internal;
 using MQTTnet.PacketDispatcher;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
+using System;
+using System.Diagnostics;
+using System.Threading;
+using System.Threading.Tasks;

 namespace MQTTnet.Client
 {
-    public class MqttClient : IMqttClient
+    public class MqttClient : Disposable, IMqttClient
    {
-        private readonly MqttPacketIdentifierProvider _packetIdentifierProvider = new MqttPacketIdentifierProvider();
-        private readonly MqttPacketDispatcher _packetDispatcher = new MqttPacketDispatcher();
-        private readonly Stopwatch _sendTracker = new Stopwatch();
-        private readonly object _disconnectLock = new object();
+        readonly MqttPacketIdentifierProvider _packetIdentifierProvider = new MqttPacketIdentifierProvider();
+        readonly MqttPacketDispatcher _packetDispatcher = new MqttPacketDispatcher();
+        readonly Stopwatch _sendTracker = new Stopwatch();
+        readonly Stopwatch _receiveTracker = new Stopwatch();
+        readonly object _disconnectLock = new object();

-        private readonly IMqttClientAdapterFactory _adapterFactory;
-        private readonly IMqttNetChildLogger _logger;
+        readonly IMqttClientAdapterFactory _adapterFactory;
+        readonly IMqttNetScopedLogger _logger;

-        private CancellationTokenSource _backgroundCancellationTokenSource;
-        private Task _packetReceiverTask;
-        private Task _keepAlivePacketsSenderTask;
+        CancellationTokenSource _backgroundCancellationTokenSource;
+        Task _packetReceiverTask;
+        Task _keepAlivePacketsSenderTask;
+        Task _publishPacketReceiverTask;

-        private IMqttChannelAdapter _adapter;
-        private bool _cleanDisconnectInitiated;
-        private long _disconnectGate;
+        AsyncQueue<MqttPublishPacket> _publishPacketReceiverQueue;
+
+        IMqttChannelAdapter _adapter;
+        bool _cleanDisconnectInitiated;
+        long _isDisconnectPending;
+        bool _isConnected;

        public MqttClient(IMqttClientAdapterFactory channelFactory, IMqttNetLogger logger)
        {
            if (logger == null) throw new ArgumentNullException(nameof(logger));

            _adapterFactory = channelFactory ?? throw new ArgumentNullException(nameof(channelFactory));
-            _logger = logger.CreateChildLogger(nameof(MqttClient));
+            _logger = logger.CreateScopedLogger(nameof(MqttClient));
        }

        public IMqttClientConnectedHandler ConnectedHandler { get; set; }
@@ -52,7 +57,7 @@ namespace MQTTnet.Client

        public IMqttApplicationMessageReceivedHandler ApplicationMessageReceivedHandler { get; set; }

-        public bool IsConnected { get; private set; }
+        public bool IsConnected => _isConnected && Interlocked.Read(ref _isDisconnectPending) == 0;

        public IMqttClientOptions Options { get; private set; }

@@ -63,6 +68,8 @@ namespace MQTTnet.Client

            ThrowIfConnected("It is not allowed to connect with a server after the connection is established.");

+            ThrowIfDisposed();
+
            MqttClientAuthenticateResult authenticateResult = null;

            try
@@ -75,26 +82,33 @@ namespace MQTTnet.Client
                _backgroundCancellationTokenSource = new CancellationTokenSource();
                var backgroundCancellationToken = _backgroundCancellationTokenSource.Token;

-                _disconnectGate = 0;
-                var adapter = _adapterFactory.CreateClientAdapter(options, _logger);
+                _isDisconnectPending = 0;
+                var adapter = _adapterFactory.CreateClientAdapter(options);
                _adapter = adapter;

-                _logger.Verbose($"Trying to connect with server '{options.ChannelOptions}' (Timeout={options.CommunicationTimeout}).");
-                await _adapter.ConnectAsync(options.CommunicationTimeout, cancellationToken).ConfigureAwait(false);
-                _logger.Verbose("Connection with server established.");
+                using (var combined = CancellationTokenSource.CreateLinkedTokenSource(backgroundCancellationToken, cancellationToken))
+                {
+                    _logger.Verbose($"Trying to connect with server '{options.ChannelOptions}' (Timeout={options.CommunicationTimeout}).");
+                    await _adapter.ConnectAsync(options.CommunicationTimeout, combined.Token).ConfigureAwait(false);
+                    _logger.Verbose("Connection with server established.");

-                _packetReceiverTask = Task.Run(() => TryReceivePacketsAsync(backgroundCancellationToken), backgroundCancellationToken);
+                    _publishPacketReceiverQueue = new AsyncQueue<MqttPublishPacket>();
+                    _publishPacketReceiverTask = Task.Run(() => ProcessReceivedPublishPackets(backgroundCancellationToken), backgroundCancellationToken);

-                authenticateResult = await AuthenticateAsync(adapter, options.WillMessage, cancellationToken).ConfigureAwait(false);
+                    _packetReceiverTask = Task.Run(() => TryReceivePacketsAsync(backgroundCancellationToken), backgroundCancellationToken);
+
+                    authenticateResult = await AuthenticateAsync(adapter, options.WillMessage, combined.Token).ConfigureAwait(false);
+                }

                _sendTracker.Restart();
+                _receiveTracker.Restart();

                if (Options.KeepAlivePeriod != TimeSpan.Zero)
                {
                    _keepAlivePacketsSenderTask = Task.Run(() => TrySendKeepAliveMessagesAsync(backgroundCancellationToken), backgroundCancellationToken);
                }

-                IsConnected = true;
+                _isConnected = true;

                _logger.Info("Connected.");

@@ -121,6 +135,10 @@ namespace MQTTnet.Client

        public async Task DisconnectAsync(MqttClientDisconnectOptions options, CancellationToken cancellationToken)
        {
+            if (options is null) throw new ArgumentNullException(nameof(options));
+
+            ThrowIfDisposed();
+
            try
            {
                _cleanDisconnectInitiated = true;
@@ -140,16 +158,24 @@ namespace MQTTnet.Client
            }
        }

+        public Task PingAsync(CancellationToken cancellationToken)
+        {
+            return SendAndReceiveAsync<MqttPingRespPacket>(new MqttPingReqPacket(), cancellationToken);
+        }
+
        public Task SendExtendedAuthenticationExchangeDataAsync(MqttExtendedAuthenticationExchangeData data, CancellationToken cancellationToken)
        {
            if (data == null) throw new ArgumentNullException(nameof(data));

+            ThrowIfDisposed();
+            ThrowIfNotConnected();
+
            return SendAsync(new MqttAuthPacket
            {
                Properties = new MqttAuthPacketProperties
                {
                    // This must always be equal to the value from the CONNECT packet. So we use it here to ensure that.
-                    AuthenticationMethod = Options.AuthenticationMethod, 
+                    AuthenticationMethod = Options.AuthenticationMethod,
                    AuthenticationData = data.AuthenticationData,
                    ReasonString = data.ReasonString,
                    UserProperties = data.UserProperties
@@ -161,6 +187,7 @@ namespace MQTTnet.Client
        {
            if (options == null) throw new ArgumentNullException(nameof(options));

+            ThrowIfDisposed();
            ThrowIfNotConnected();

            var subscribePacket = _adapter.PacketFormatterAdapter.DataConverter.CreateSubscribePacket(options);
@@ -174,6 +201,7 @@ namespace MQTTnet.Client
        {
            if (options == null) throw new ArgumentNullException(nameof(options));

+            ThrowIfDisposed();
            ThrowIfNotConnected();

            var unsubscribePacket = _adapter.PacketFormatterAdapter.DataConverter.CreateUnsubscribePacket(options);
@@ -189,6 +217,7 @@ namespace MQTTnet.Client

            MqttTopicValidator.ThrowIfInvalid(applicationMessage.Topic);

+            ThrowIfDisposed();
            ThrowIfNotConnected();

            var publishPacket = _adapter.PacketFormatterAdapter.DataConverter.CreatePublishPacket(applicationMessage);
@@ -214,17 +243,32 @@ namespace MQTTnet.Client
            }
        }

-        public void Dispose()
+        void Cleanup()
        {
            _backgroundCancellationTokenSource?.Cancel(false);
            _backgroundCancellationTokenSource?.Dispose();
            _backgroundCancellationTokenSource = null;

+            _publishPacketReceiverQueue?.Dispose();
+            _publishPacketReceiverQueue = null;
+
            _adapter?.Dispose();
-            _adapter = null;
        }

-        private async Task<MqttClientAuthenticateResult> AuthenticateAsync(IMqttChannelAdapter channelAdapter, MqttApplicationMessage willApplicationMessage, CancellationToken cancellationToken)
+
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                Cleanup();
+
+                DisconnectedHandler = null;
+            }
+
+            base.Dispose(disposing);
+        }
+
+        async Task<MqttClientAuthenticateResult> AuthenticateAsync(IMqttChannelAdapter channelAdapter, MqttApplicationMessage willApplicationMessage, CancellationToken cancellationToken)
        {
            var connectPacket = channelAdapter.PacketFormatterAdapter.DataConverter.CreateConnectPacket(
                willApplicationMessage,
@@ -235,7 +279,7 @@ namespace MQTTnet.Client

            if (result.ResultCode != MqttClientConnectResultCode.Success)
            {
-                throw new MqttConnectingFailedException(result.ResultCode);
+                throw new MqttConnectingFailedException(result);
            }

            _logger.Verbose("Authenticated MQTT connection with server established.");
@@ -243,23 +287,26 @@ namespace MQTTnet.Client
            return result;
        }

-        private void ThrowIfNotConnected()
+        void ThrowIfNotConnected()
        {
-            if (!IsConnected || Interlocked.Read(ref _disconnectGate) == 1) throw new MqttCommunicationException("The client is not connected.");
+            if (!IsConnected || Interlocked.Read(ref _isDisconnectPending) == 1)
+            {
+                throw new MqttCommunicationException("The client is not connected.");
+            }
        }

-        private void ThrowIfConnected(string message)
+        void ThrowIfConnected(string message)
        {
            if (IsConnected) throw new MqttProtocolViolationException(message);
        }

-        private async Task DisconnectInternalAsync(Task sender, Exception exception, MqttClientAuthenticateResult authenticateResult)
+        async Task DisconnectInternalAsync(Task sender, Exception exception, MqttClientAuthenticateResult authenticateResult)
        {
            var clientWasConnected = IsConnected;
+            var reasonCode = MqttClientDisconnectReason.NormalDisconnection;

-            InitiateDisconnect();
-
-            IsConnected = false;
+            TryInitiateDisconnect();
+            _isConnected = false;

            try
            {
@@ -269,18 +316,32 @@ namespace MQTTnet.Client
                    await _adapter.DisconnectAsync(Options.CommunicationTimeout, CancellationToken.None).ConfigureAwait(false);
                }

-                await WaitForTaskAsync(_packetReceiverTask, sender).ConfigureAwait(false);
-                await WaitForTaskAsync(_keepAlivePacketsSenderTask, sender).ConfigureAwait(false);
-
                _logger.Verbose("Disconnected from adapter.");
            }
            catch (Exception adapterException)
            {
                _logger.Warning(adapterException, "Error while disconnecting from adapter.");
+                reasonCode = MqttClientDisconnectReason.UnspecifiedError;
+            }
+
+            try
+            {
+                var receiverTask = WaitForTaskAsync(_packetReceiverTask, sender);
+                var publishPacketReceiverTask = WaitForTaskAsync(_publishPacketReceiverTask, sender);
+                var keepAliveTask = WaitForTaskAsync(_keepAlivePacketsSenderTask, sender);
+
+                await Task.WhenAll(receiverTask, publishPacketReceiverTask, keepAliveTask).ConfigureAwait(false);
+
+                _publishPacketReceiverQueue?.Dispose();
+            }
+            catch (Exception e)
+            {
+                _logger.Warning(e, "Error while waiting for internal tasks.");
+                reasonCode = MqttClientDisconnectReason.UnspecifiedError;
            }
            finally
            {
-                Dispose();
+                Cleanup();
                _cleanDisconnectInitiated = false;

                _logger.Info("Disconnected.");
@@ -290,12 +351,12 @@ namespace MQTTnet.Client
                {
                    // This handler must be executed in a new thread because otherwise a dead lock may happen
                    // when trying to reconnect in that handler etc.
-                    Task.Run(() => disconnectedHandler.HandleDisconnectedAsync(new MqttClientDisconnectedEventArgs(clientWasConnected, exception, authenticateResult))).Forget(_logger);
+                    Task.Run(() => disconnectedHandler.HandleDisconnectedAsync(new MqttClientDisconnectedEventArgs(clientWasConnected, exception, authenticateResult, reasonCode))).Forget(_logger);
                }
            }
        }

-        private void InitiateDisconnect()
+        void TryInitiateDisconnect()
        {
            lock (_disconnectLock)
            {
@@ -315,68 +376,78 @@ namespace MQTTnet.Client
            }
        }

-        private Task SendAsync(MqttBasePacket packet, CancellationToken cancellationToken)
+        Task SendAsync(MqttBasePacket packet, CancellationToken cancellationToken)
        {
-            if (cancellationToken.IsCancellationRequested)
-            {
-                return Task.FromResult(0);
-            }
+            cancellationToken.ThrowIfCancellationRequested();

            _sendTracker.Restart();

            return _adapter.SendPacketAsync(packet, Options.CommunicationTimeout, cancellationToken);
        }

-        private async Task<TResponsePacket> SendAndReceiveAsync<TResponsePacket>(MqttBasePacket requestPacket, CancellationToken cancellationToken) where TResponsePacket : MqttBasePacket
+        async Task<TResponsePacket> SendAndReceiveAsync<TResponsePacket>(MqttBasePacket requestPacket, CancellationToken cancellationToken) where TResponsePacket : MqttBasePacket
        {
            cancellationToken.ThrowIfCancellationRequested();
-
-            _sendTracker.Restart();
-
+            
            ushort identifier = 0;
            if (requestPacket is IMqttPacketWithIdentifier packetWithIdentifier && packetWithIdentifier.PacketIdentifier.HasValue)
            {
                identifier = packetWithIdentifier.PacketIdentifier.Value;
            }

-            using (var packetAwaiter = _packetDispatcher.AddPacketAwaiter<TResponsePacket>(identifier))
+            using (var packetAwaiter = _packetDispatcher.AddAwaiter<TResponsePacket>(identifier))
            {
                try
                {
+                    _sendTracker.Restart();
+
                    await _adapter.SendPacketAsync(requestPacket, Options.CommunicationTimeout, cancellationToken).ConfigureAwait(false);
+                }
+                catch (Exception e)
+                {
+                    _logger.Warning(e, "Error when sending packet of type '{0}'.", typeof(TResponsePacket).Name);
+                    packetAwaiter.Cancel();
+                }
+
+                try
+                {
                    return await packetAwaiter.WaitOneAsync(Options.CommunicationTimeout).ConfigureAwait(false);
                }
-                catch (MqttCommunicationTimedOutException)
+                catch (Exception exception)
                {
-                    _logger.Warning(null, "Timeout while waiting for packet of type '{0}'.", typeof(TResponsePacket).Name);
+                    if (exception is MqttCommunicationTimedOutException)
+                    {
+                        _logger.Warning(null, "Timeout while waiting for packet of type '{0}'.", typeof(TResponsePacket).Name);
+                    }
+
                    throw;
                }
            }
        }

-        private async Task TrySendKeepAliveMessagesAsync(CancellationToken cancellationToken)
+        async Task TrySendKeepAliveMessagesAsync(CancellationToken cancellationToken)
        {
            try
            {
                _logger.Verbose("Start sending keep alive packets.");

+                var keepAlivePeriod = Options.KeepAlivePeriod;
+
                while (!cancellationToken.IsCancellationRequested)
                {
                    // Values described here: [MQTT-3.1.2-24].
-                    var keepAliveSendInterval = TimeSpan.FromSeconds(Options.KeepAlivePeriod.TotalSeconds * 0.75);
-                    if (Options.KeepAliveSendInterval.HasValue)
-                    {
-                        keepAliveSendInterval = Options.KeepAliveSendInterval.Value;
-                    }
-
-                    var waitTime = keepAliveSendInterval - _sendTracker.Elapsed;
+                    var waitTime = keepAlivePeriod - _sendTracker.Elapsed;
+                    
                    if (waitTime <= TimeSpan.Zero)
                    {
                        await SendAndReceiveAsync<MqttPingRespPacket>(new MqttPingReqPacket(), cancellationToken).ConfigureAwait(false);
-                        waitTime = keepAliveSendInterval;
                    }

-                    await Task.Delay(waitTime, cancellationToken).ConfigureAwait(false);
+                    // Wait a fixed time in all cases. Calculation of the remaining time is complicated
+                    // due to some edge cases and was buggy in the past. Now we wait half a second because the
+                    // min keep alive value is one second so that the server will wait 1.5 seconds for a PING
+                    // packet.
+                    await Task.Delay(TimeSpan.FromMilliseconds(100), cancellationToken).ConfigureAwait(false);
                }
            }
            catch (Exception exception)
@@ -391,11 +462,11 @@ namespace MQTTnet.Client
                }
                else if (exception is MqttCommunicationException)
                {
-                    _logger.Warning(exception, "MQTT communication exception while sending/receiving keep alive packets.");
+                    _logger.Warning(exception, "Communication error while sending/receiving keep alive packets.");
                }
                else
                {
-                    _logger.Error(exception, "Unhandled exception while sending/receiving keep alive packets.");
+                    _logger.Error(exception, "Error exception while sending/receiving keep alive packets.");
                }

                if (!DisconnectIsPending())
@@ -409,7 +480,7 @@ namespace MQTTnet.Client
            }
        }

-        private async Task TryReceivePacketsAsync(CancellationToken cancellationToken)
+        async Task TryReceivePacketsAsync(CancellationToken cancellationToken)
        {
            try
            {
@@ -449,11 +520,11 @@ namespace MQTTnet.Client
                }
                else if (exception is MqttCommunicationException)
                {
-                    _logger.Warning(exception, "MQTT communication exception while receiving packets.");
+                    _logger.Warning(exception, "Communication error while receiving packets.");
                }
                else
                {
-                    _logger.Error(exception, "Unhandled exception while receiving packets.");
+                    _logger.Error(exception, "Error while receiving packets.");
                }

                _packetDispatcher.Dispatch(exception);
@@ -469,13 +540,15 @@ namespace MQTTnet.Client
            }
        }

-        private async Task TryProcessReceivedPacketAsync(MqttBasePacket packet, CancellationToken cancellationToken)
+        async Task TryProcessReceivedPacketAsync(MqttBasePacket packet, CancellationToken cancellationToken)
        {
            try
            {
+                _receiveTracker.Restart();
+
                if (packet is MqttPublishPacket publishPacket)
                {
-                    await TryProcessReceivedPublishPacketAsync(publishPacket, cancellationToken).ConfigureAwait(false);
+                    EnqueueReceivedPublishPacket(publishPacket);
                }
                else if (packet is MqttPubRelPacket pubRelPacket)
                {
@@ -521,11 +594,11 @@ namespace MQTTnet.Client
                }
                else if (exception is MqttCommunicationException)
                {
-                    _logger.Warning(exception, "MQTT communication exception while receiving packets.");
+                    _logger.Warning(exception, "Communication error while receiving packets.");
                }
                else
                {
-                    _logger.Error(exception, "Unhandled exception while receiving packets.");
+                    _logger.Error(exception, "Error while receiving packets.");
                }

                _packetDispatcher.Dispatch(exception);
@@ -537,64 +610,88 @@ namespace MQTTnet.Client
            }
        }

-        private async Task TryProcessReceivedPublishPacketAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
+        void EnqueueReceivedPublishPacket(MqttPublishPacket publishPacket)
        {
            try
            {
-                if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtMostOnce)
-                {
-                    await HandleReceivedApplicationMessageAsync(publishPacket).ConfigureAwait(false);
-                }
-                else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtLeastOnce)
-                {
-                    if (await HandleReceivedApplicationMessageAsync(publishPacket).ConfigureAwait(false))
-                    {
-                        await SendAsync(new MqttPubAckPacket
-                        {
-                            PacketIdentifier = publishPacket.PacketIdentifier,
-                            ReasonCode = MqttPubAckReasonCode.Success
-                        }, cancellationToken).ConfigureAwait(false);
-                    }
-                }
-                else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.ExactlyOnce)
-                {
-                    if (await HandleReceivedApplicationMessageAsync(publishPacket).ConfigureAwait(false))
-                    {
-                        var pubRecPacket = new MqttPubRecPacket
-                        {
-                            PacketIdentifier = publishPacket.PacketIdentifier,
-                            ReasonCode = MqttPubRecReasonCode.Success
-                        };
-
-                        await SendAsync(pubRecPacket, cancellationToken).ConfigureAwait(false);
-                    }                    
-                }
-                else
-                {
-                    throw new MqttProtocolViolationException("Received a not supported QoS level.");
-                }
+                _publishPacketReceiverQueue.Enqueue(publishPacket);
            }
            catch (Exception exception)
            {
-                _logger.Error(exception, "Unhandled exception while handling application message.");
+                _logger.Error(exception, "Error while enqueueing application message.");
            }
        }

-        private async Task<MqttClientPublishResult> PublishAtMostOnce(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
+        async Task ProcessReceivedPublishPackets(CancellationToken cancellationToken)
+        {
+            while (!cancellationToken.IsCancellationRequested)
+            {
+                try
+                {
+                    var publishPacketDequeueResult = await _publishPacketReceiverQueue.TryDequeueAsync(cancellationToken);
+
+                    if (!publishPacketDequeueResult.IsSuccess)
+                    {
+                        return;
+                    }
+
+                    var publishPacket = publishPacketDequeueResult.Item;
+
+                    if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtMostOnce)
+                    {
+                        await HandleReceivedApplicationMessageAsync(publishPacket).ConfigureAwait(false);
+                    }
+                    else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtLeastOnce)
+                    {
+                        if (await HandleReceivedApplicationMessageAsync(publishPacket).ConfigureAwait(false))
+                        {
+                            await SendAsync(new MqttPubAckPacket
+                            {
+                                PacketIdentifier = publishPacket.PacketIdentifier,
+                                ReasonCode = MqttPubAckReasonCode.Success
+                            }, cancellationToken).ConfigureAwait(false);
+                        }
+                    }
+                    else if (publishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.ExactlyOnce)
+                    {
+                        if (await HandleReceivedApplicationMessageAsync(publishPacket).ConfigureAwait(false))
+                        {
+                            var pubRecPacket = new MqttPubRecPacket
+                            {
+                                PacketIdentifier = publishPacket.PacketIdentifier,
+                                ReasonCode = MqttPubRecReasonCode.Success
+                            };
+
+                            await SendAsync(pubRecPacket, cancellationToken).ConfigureAwait(false);
+                        }
+                    }
+                    else
+                    {
+                        throw new MqttProtocolViolationException("Received a not supported QoS level.");
+                    }
+                }
+                catch (Exception exception)
+                {
+                    _logger.Error(exception, "Error while handling application message.");
+                }
+            }
+        }
+
+        async Task<MqttClientPublishResult> PublishAtMostOnce(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
        {
            // No packet identifier is used for QoS 0 [3.3.2.2 Packet Identifier]
            await SendAsync(publishPacket, cancellationToken).ConfigureAwait(false);
            return _adapter.PacketFormatterAdapter.DataConverter.CreatePublishResult(null);
        }

-        private async Task<MqttClientPublishResult> PublishAtLeastOnceAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
+        async Task<MqttClientPublishResult> PublishAtLeastOnceAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
        {
            publishPacket.PacketIdentifier = _packetIdentifierProvider.GetNextPacketIdentifier();
            var response = await SendAndReceiveAsync<MqttPubAckPacket>(publishPacket, cancellationToken).ConfigureAwait(false);
            return _adapter.PacketFormatterAdapter.DataConverter.CreatePublishResult(response);
        }

-        private async Task<MqttClientPublishResult> PublishExactlyOnceAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
+        async Task<MqttClientPublishResult> PublishExactlyOnceAsync(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
        {
            publishPacket.PacketIdentifier = _packetIdentifierProvider.GetNextPacketIdentifier();

@@ -611,7 +708,7 @@ namespace MQTTnet.Client
            return _adapter.PacketFormatterAdapter.DataConverter.CreatePublishResult(pubRecPacket, pubCompPacket);
        }

-        private async Task<bool> HandleReceivedApplicationMessageAsync(MqttPublishPacket publishPacket)
+        async Task<bool> HandleReceivedApplicationMessageAsync(MqttPublishPacket publishPacket)
        {
            var applicationMessage = _adapter.PacketFormatterAdapter.DataConverter.CreateApplicationMessage(publishPacket);

@@ -626,15 +723,25 @@ namespace MQTTnet.Client
            return true;
        }

-        private static async Task WaitForTaskAsync(Task task, Task sender)
+        async Task WaitForTaskAsync(Task task, Task sender)
        {
-            if (task == sender || task == null)
+            if (task == null)
            {
                return;
            }

-            if (task.IsCanceled || task.IsCompleted || task.IsFaulted)
+            if (task == sender)
            {
+                // Return here to avoid deadlocks, but first any eventual exception in the task
+                // must be handled to avoid not getting an unhandled task exception
+                if (!task.IsFaulted)
+                {
+                    return;
+                }
+
+                // By accessing the Exception property the exception is considered handled and will
+                // not result in an unhandled task exception later by the finalizer
+                _logger.Warning(task.Exception, "Error while waiting for background task.");
                return;
            }

@@ -647,9 +754,9 @@ namespace MQTTnet.Client
            }
        }

-        private bool DisconnectIsPending()
+        bool DisconnectIsPending()
        {
-            return Interlocked.CompareExchange(ref _disconnectGate, 1, 0) != 0;
+            return Interlocked.CompareExchange(ref _isDisconnectPending, 1, 0) != 0;
        }
    }
-}
+}
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
-using MQTTnet.Client.Connecting;
+using MQTTnet.Client.Connecting;
 using MQTTnet.Client.Disconnecting;
 using MQTTnet.Client.ExtendedAuthenticationExchange;
 using MQTTnet.Client.Options;
@@ -11,6 +7,10 @@ using MQTTnet.Client.Receiving;
 using MQTTnet.Client.Subscribing;
 using MQTTnet.Client.Unsubscribing;
 using MQTTnet.Protocol;
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;

 namespace MQTTnet.Client
 {
@@ -128,10 +128,10 @@ namespace MQTTnet.Client
        {
            if (client == null) throw new ArgumentNullException(nameof(client));

-            return client.DisconnectAsync(null);
+            return client.DisconnectAsync(new MqttClientDisconnectOptions());
        }

-        public static Task<MqttClientSubscribeResult> SubscribeAsync(this IMqttClient client, params TopicFilter[] topicFilters)
+        public static Task<MqttClientSubscribeResult> SubscribeAsync(this IMqttClient client, params MqttTopicFilter[] topicFilters)
        {
            if (client == null) throw new ArgumentNullException(nameof(client));
            if (topicFilters == null) throw new ArgumentNullException(nameof(topicFilters));
@@ -147,7 +147,7 @@ namespace MQTTnet.Client
            if (client == null) throw new ArgumentNullException(nameof(client));
            if (topic == null) throw new ArgumentNullException(nameof(topic));

-            return client.SubscribeAsync(new TopicFilterBuilder().WithTopic(topic).WithQualityOfServiceLevel(qualityOfServiceLevel).Build());
+            return client.SubscribeAsync(new MqttTopicFilterBuilder().WithTopic(topic).WithQualityOfServiceLevel(qualityOfServiceLevel).Build());
        }

        public static Task<MqttClientSubscribeResult> SubscribeAsync(this IMqttClient client, string topic)
@@ -155,7 +155,7 @@ namespace MQTTnet.Client
            if (client == null) throw new ArgumentNullException(nameof(client));
            if (topic == null) throw new ArgumentNullException(nameof(topic));

-            return client.SubscribeAsync(new TopicFilterBuilder().WithTopic(topic).Build());
+            return client.SubscribeAsync(new MqttTopicFilterBuilder().WithTopic(topic).Build());
        }

        public static Task<MqttClientUnsubscribeResult> UnsubscribeAsync(this IMqttClient client, params string[] topicFilters)
@@ -1,6 +1,8 @@
-using System;
-using MQTTnet.Client.ExtendedAuthenticationExchange;
+using MQTTnet.Client.ExtendedAuthenticationExchange;
 using MQTTnet.Formatter;
+using MQTTnet.Packets;
+using System;
+using System.Collections.Generic;

 namespace MQTTnet.Client.Options
 {
@@ -12,11 +14,9 @@ namespace MQTTnet.Client.Options
        IMqttExtendedAuthenticationExchangeHandler ExtendedAuthenticationExchangeHandler { get; }
        MqttProtocolVersion ProtocolVersion { get; }
        IMqttClientChannelOptions ChannelOptions { get; }
-        
+
        TimeSpan CommunicationTimeout { get; }
        TimeSpan KeepAlivePeriod { get; }
-        TimeSpan? KeepAliveSendInterval { get; }
-        
        MqttApplicationMessage WillMessage { get; }
        uint? WillDelayInterval { get; }

@@ -28,5 +28,6 @@ namespace MQTTnet.Client.Options
        bool? RequestResponseInformation { get; }
        uint? SessionExpiryInterval { get; }
        ushort? TopicAliasMaximum { get; }
+        List<MqttUserProperty> UserProperties { get; set; }
    }
 }
@@ -0,0 +1,16 @@
+using System.Net.Security;
+using System.Security.Cryptography.X509Certificates;
+
+namespace MQTTnet.Client.Options
+{
+    public class MqttClientCertificateValidationCallbackContext
+    {
+        public X509Certificate Certificate { get; set; }
+
+        public X509Chain Chain { get; set; }
+
+        public SslPolicyErrors SslPolicyErrors { get; set; }
+
+        public IMqttClientChannelOptions ClientOptions { get; set; }
+    }
+}
--- a/Show More
+++ b/Show More