Add Unit Tests

.editorconfig

@@ -40,6 +40,7 @@ dotnet_style_qualification_for_method = false:suggestion
 dotnet_style_qualification_for_property = false:suggestion
 
 # ReSharper properties
+resharper_autodetect_indent_settings = true
 resharper_default_private_modifier = implicit
 resharper_place_accessorholder_attribute_on_same_line = false
 resharper_use_indent_from_vs = false
@@ -60,7 +61,7 @@ resharper_web_config_wrong_module_highlighting = warning
 [*]
 charset = utf-8
 end_of_line = crlf
-trim_trailing_whitespace = true
+trim_trailing_whitespace = false
 insert_final_newline = false
 indent_style = space
 indent_size = 4

.github/workflows/ReleaseNotes.md

@@ -1,3 +1,4 @@
-* Client: Fixed wrong timeout for keep alive check (thanks to @Erw1nT, #2129)
-* Client: Fixed extended authentication (thanks to @chkr1011, #2132).
-* Server: Fixed extended authentication (thanks to @chkr1011, #2132).
+* [Client] Fixed _PlatformNotSupportedException_ when using Blazor (#1755, thanks to @Nickztar).
+* [Server] Fixed _NullReferenceException_ in retained messages management (#1762, thanks to @logicaloud).
+* [Server] Exposed new option which allows disabling packet fragmentation (#1753).
+* [Server] Expired sessions will no longer be used when a client connects (#1756).

.github/workflows/ci.yml

@@ -3,7 +3,7 @@ name: CI
 on: [push, pull_request]
 
 env:
-  VERSION: "4.3.8.${{github.run_number}}"
+  VERSION: "4.2.1.${{github.run_number}}"
 
 jobs:
   build:
@@ -12,12 +12,12 @@ jobs:
 
     steps:
       - name: Setup Windows SDK
-        uses: GuillaumeFalourd/setup-windows10-sdk-action@v2.4
+        uses: GuillaumeFalourd/setup-windows10-sdk-action@v1
         with:
           sdk-version: 18362
 
       - name: Setup .NET SDK
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v1.9.0
         with:
           dotnet-version: |
             3.1.x
@@ -28,7 +28,7 @@ jobs:
         uses: microsoft/setup-msbuild@v1.1
 
       - name: Checkout Code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v2
 
       - name: Setup Signing Certificate
         run: |
@@ -42,41 +42,23 @@ jobs:
       - name: Build solution
         run: msbuild MQTTnet.sln /t:Build /p:Configuration="Release" /verbosity:m /p:FileVersion=${{ env.VERSION }} /p:AssemblyVersion=${{ env.VERSION }} /p:PackageVersion=${{ env.VERSION }} /p:SignAssembly=true /p:AssemblyOriginatorKeyFile=${{ github.workspace }}\certificate.snk
 
+      - name: Collect nuget Packages
+        uses: actions/upload-artifact@v2
+        with:
+          name: nuget Packages
+          path: |
+            **\*.nupkg
+            **\*.snupkg
+
       - name: Setup VSTest
         uses: darenm/Setup-VSTest@v1
 
       - name: Core Tests
-        run: vstest.console.exe Source\MQTTnet.Tests\bin\Release\net7.0\MQTTnet.Tests.dll
+        run: vstest.console.exe Source\MQTTnet.Tests\bin\Release\net6.0\MQTTnet.Tests.dll
 
       - name: ASP.NET Tests
         run: vstest.console.exe Source\MQTTnet.AspNetCore.Tests\bin\Release\netcoreapp3.1\MQTTnet.AspNetCore.Tests.dll
 
-      - name: Install sign CLI tool
-        run: dotnet tool install --tool-path . sign --version 0.9.0-beta.23127.3
-
-      - name: Sign nugets
-        shell: pwsh
-        run: >
-          ./sign code azure-key-vault `
-          "**/*.nupkg" `
-          --base-directory "${{ github.workspace }}/Source" `
-          --publisher-name "MQTTnet" `
-          --description "MQTTnet" `
-          --description-url "https://github.com/dotnet/MQTTnet" `
-          --azure-key-vault-tenant-id "${{ secrets.AZURE_TENANT_ID }}" `
-          --azure-key-vault-client-id "${{ secrets.AZURE_CLIENT_ID }}" `
-          --azure-key-vault-client-secret "${{ secrets.AZURE_CLIENT_SECRET }}" `
-          --azure-key-vault-certificate "${{ secrets.KEY_VAULT_CERTIFICATE_ID }}" `
-          --azure-key-vault-url "${{ secrets.KEY_VAULT_URL }}"
-
-      - name: Upload signed nuget packages
-        uses: actions/upload-artifact@v4
-        with:
-          name: signed-nugets
-          path: |
-            ${{ github.workspace }}/Source/**/*.nupkg
-            ${{ github.workspace }}/Source/**/*.snupkg
-
       - name: Publish MyGet nugets
         if: ${{ github.event_name == 'push' }}
-        run: dotnet nuget push ${{ github.workspace }}/Source/**/*.nupkg -k ${{ secrets.MYGET_API_KEY }} -s https://www.myget.org/F/mqttnet/api/v3/index.json --skip-duplicate
+        run: dotnet nuget push **/*.nupkg -k ${{ secrets.MYGET_API_KEY }} -s https://www.myget.org/F/mqttnet/api/v3/index.json --skip-duplicate

MQTTnet.sln

@@ -7,11 +7,9 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet", "Source\MQTTnet\M
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{B3F60ECB-45BA-4C66-8903-8BB89CA67998}"
 	ProjectSection(SolutionItems) = preProject
-		CODE-OF-CONDUCT.md = CODE-OF-CONDUCT.md
 		LICENSE = LICENSE
 		README.md = README.md
-		.github\workflows\ReleaseNotes.md = .github\workflows\ReleaseNotes.md
-		.github\workflows\ci.yml = .github\workflows\ci.yml
+		CODE-OF-CONDUCT.md = CODE-OF-CONDUCT.md
 	EndProjectSection
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.AspNetCore", "Source\MQTTnet.AspnetCore\MQTTnet.AspNetCore.csproj", "{F10C4060-F7EE-4A83-919F-FF723E72F94A}"
@@ -22,19 +20,17 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.Extensions.ManagedC
 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("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.Samples", "Samples\MQTTnet.Samples.csproj", "{71CF35F5-3327-4A91-AAF4-5340F6701771}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.Samples", "Samples\MQTTnet.Samples.csproj", "{71CF35F5-3327-4A91-AAF4-5340F6701771}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.Tests", "Source\MQTTnet.Tests\MQTTnet.Tests.csproj", "{B270F32A-9F3E-42EE-A989-813E35E29ADB}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.Tests", "Source\MQTTnet.Tests\MQTTnet.Tests.csproj", "{B270F32A-9F3E-42EE-A989-813E35E29ADB}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.AspNetCore.Tests", "Source\MQTTnet.AspNetCore.Tests\MQTTnet.AspNetCore.Tests.csproj", "{A238BBBF-C75F-482D-9CC3-BB34ABA9B675}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.AspNetCore.Tests", "Source\MQTTnet.AspNetCore.Tests\MQTTnet.AspNetCore.Tests.csproj", "{A238BBBF-C75F-482D-9CC3-BB34ABA9B675}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.Benchmarks", "Source\MQTTnet.Benchmarks\MQTTnet.Benchmarks.csproj", "{2F516E76-AAC4-4219-B7D1-34CDD3CFF381}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.Benchmarks", "Source\MQTTnet.Benchmarks\MQTTnet.Benchmarks.csproj", "{2F516E76-AAC4-4219-B7D1-34CDD3CFF381}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.TestApp", "Source\MQTTnet.TestApp\MQTTnet.TestApp.csproj", "{175D5340-CC5B-4542-939D-4E7D15A0BC8D}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.TestApp", "Source\MQTTnet.TestApp\MQTTnet.TestApp.csproj", "{175D5340-CC5B-4542-939D-4E7D15A0BC8D}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.AspTestApp", "Source\MQTTnet.AspTestApp\MQTTnet.AspTestApp.csproj", "{72867E4C-4E15-4E8E-8FAB-AE9253286BBC}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MQTTnet.Extensions.TopicTemplate", "Source\MQTTnet.Extensions.TopicTemplate\MQTTnet.Extensions.TopicTemplate.csproj", "{374D5861-F7A6-42A2-8CBE-040846000EF9}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MQTTnet.AspTestApp", "Source\MQTTnet.AspTestApp\MQTTnet.AspTestApp.csproj", "{72867E4C-4E15-4E8E-8FAB-AE9253286BBC}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -86,14 +82,12 @@ Global
 		{72867E4C-4E15-4E8E-8FAB-AE9253286BBC}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{72867E4C-4E15-4E8E-8FAB-AE9253286BBC}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{72867E4C-4E15-4E8E-8FAB-AE9253286BBC}.Release|Any CPU.Build.0 = Release|Any CPU
-		{374D5861-F7A6-42A2-8CBE-040846000EF9}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{374D5861-F7A6-42A2-8CBE-040846000EF9}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{374D5861-F7A6-42A2-8CBE-040846000EF9}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{374D5861-F7A6-42A2-8CBE-040846000EF9}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {07536672-5CBC-4BE3-ACE0-708A431A7894}
 	EndGlobalSection

MQTTnet.sln.DotSettings

@@ -230,7 +230,6 @@
 	<s:String x:Key="/Default/CodeStyle/FileHeader/FileHeaderText/@EntryValue">Licensed to the .NET Foundation under one or more agreements.
 The .NET Foundation licenses this file to you under the MIT license.
 See the LICENSE file in the project root for more information.</s:String>
-	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EFeature_002EServices_002ECodeCleanup_002EFileHeader_002EFileHeaderSettingsMigrate/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpAttributeForSingleLineMethodUpgrade/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpKeepExistingMigration/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpPlaceEmbeddedOnSameLineMigration/@EntryIndexedValue">True</s:Boolean>
@@ -241,7 +240,6 @@ See the LICENSE file in the project root for more information.</s:String>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002ECSharpPlaceAttributeOnSameLineMigration/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EMigrateBlankLinesAroundFieldToBlankLinesAroundProperty/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EMigrateThisQualifierSettings/@EntryIndexedValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/UserDictionary/Words/=catched/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=CONNACK/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=PINGREQ/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=PINGRESP/@EntryIndexedValue">True</s:Boolean>

Samples/Client/Client_Connection_Samples.cs

@@ -7,14 +7,10 @@
 // ReSharper disable InconsistentNaming
 
 using System.Security.Authentication;
-using System.Security.Cryptography.X509Certificates;
-using System.Text;
 using MQTTnet.Client;
 using MQTTnet.Extensions.WebSocket4Net;
 using MQTTnet.Formatter;
-using MQTTnet.Protocol;
 using MQTTnet.Samples.Helpers;
-using MQTTnet.Server;
 
 namespace MQTTnet.Samples.Client;
 
@@ -74,6 +70,32 @@ public static class Client_Connection_Samples
             await mqttClient.DisconnectAsync(mqttClientDisconnectOptions, CancellationToken.None);
         }
     }
+    
+    public static async Task Connect_With_Amazon_AWS()
+    {
+        /*
+         * This sample creates a simple MQTT client and connects to an Amazon Web Services broker.
+         *
+         * The broker requires special settings which are set here.
+         */
+
+        var mqttFactory = new MqttFactory();
+
+        using (var mqttClient = mqttFactory.CreateMqttClient())
+        {
+            var mqttClientOptions = new MqttClientOptionsBuilder()
+                .WithTcpServer("amazon.web.services.broker")
+                // Disabling packet fragmentation is very important!  
+                .WithoutPacketFragmentation()
+                .Build();
+            
+            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+
+            Console.WriteLine("The MQTT client is connected.");
+
+            await mqttClient.DisconnectAsync();
+        }
+    }
 
     public static async Task Connect_Client_Timeout()
     {
@@ -103,105 +125,6 @@ public static class Client_Connection_Samples
         }
     }
 
-    public static async Task Connect_Using_Extended_Authentication()
-    {
-        /*
-         * This sample uses enhanced (aka extended) authentication (Kerberos) when creating the connection.
-         */
-
-        /*
-         * Server part...
-         */
-
-        var mqttFactory = new MqttFactory();
-
-        var serverOptions = mqttFactory.CreateServerOptionsBuilder().WithDefaultEndpoint().Build();
-        var server = mqttFactory.CreateMqttServer(serverOptions);
-
-        server.ValidatingConnectionAsync += async args =>
-        {
-            if (args.AuthenticationMethod == "GS2-KRB5")
-            {
-                var result = await args.SendExtendedAuthenticationExchangeDataAsync(new MqttExtendedAuthenticationExchangeOptions());
-
-                Console.WriteLine($"Received AUTH data from client: {Encoding.UTF8.GetString(result.AuthenticationData)}");
-
-                var authOptions = mqttFactory.CreateMqttExtendedAuthenticationExchangeOptionsBuilder().WithAuthenticationData("reply context token").Build();
-
-                result = await args.SendExtendedAuthenticationExchangeDataAsync(authOptions);
-
-                Console.WriteLine($"Received AUTH data from client: {Encoding.UTF8.GetString(result.AuthenticationData)}");
-
-                args.ResponseAuthenticationData = "outcome of authentication"u8.ToArray();
-
-                // Authentication DONE!
-                args.ReasonCode = MqttConnectReasonCode.Success; // Also the default!
-            }
-            else
-            {
-                args.ReasonCode = MqttConnectReasonCode.BadAuthenticationMethod;
-            }
-        };
-
-        await server.StartAsync();
-
-        /*
-         * Client part...
-         */
-
-        var mqttClientFactory = new MqttFactory();
-
-        // Use Kerberos sample from the MQTT RFC.
-        var kerberosAuthenticationHandler = new SampleClientKerberosAuthenticationHandler();
-
-        var clientOptions = mqttClientFactory.CreateClientOptionsBuilder()
-            .WithTcpServer("localhost")
-            .WithProtocolVersion(MqttProtocolVersion.V500)
-            .WithExtendedAuthenticationExchangeHandler(kerberosAuthenticationHandler)
-            .WithAuthentication("GS2-KRB5", Array.Empty<byte>())
-            .Build();
-
-        var client = mqttClientFactory.CreateMqttClient();
-
-        var result = await client.ConnectAsync(clientOptions);
-
-        Console.WriteLine($"Client connect result: {result.ResultCode}");
-    }
-
-    class SampleClientKerberosAuthenticationHandler : IMqttExtendedAuthenticationExchangeHandler
-    {
-        private readonly Queue<byte[]> clientTokens = new Queue<byte[]>();
-
-        public SampleClientKerberosAuthenticationHandler()
-        {
-            // The Kerberos sample from the MQTT RFC sends two client tokens after the initial empty token.
-            clientTokens.Enqueue(Encoding.UTF8.GetBytes("initial context token"));
-            clientTokens.Enqueue(Array.Empty<byte>());
-        }
-
-        public async Task HandleRequestAsync(MqttExtendedAuthenticationExchangeContext context)
-        {
-            if (context.AuthenticationMethod != "GS2-KRB5")
-            {
-                throw new InvalidOperationException("Wrong authentication method");
-            }
-
-            Console.WriteLine($"Received AUTH data from server: {Encoding.UTF8.GetString(context.AuthenticationData)}");
-
-            if (!clientTokens.TryDequeue(out var clientToken))
-            {
-                throw new InvalidOperationException("No more client tokens available");
-            }
-
-            var sendOptions = new MqttExtendedAuthenticationExchangeData
-            {
-                AuthenticationData = clientToken
-            };
-
-            await context.Client.SendExtendedAuthenticationExchangeDataAsync(sendOptions);
-        }
-    }
-
     public static async Task Connect_Client_Using_MQTTv5()
     {
         /*
@@ -238,15 +161,15 @@ public static class Client_Connection_Samples
         using (var mqttClient = mqttFactory.CreateMqttClient())
         {
             var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("mqtt.fluux.io")
-                .WithTlsOptions(
+                .WithTls(
                     o =>
                     {
                         // The used public broker sometimes has invalid certificates. This sample accepts all
                         // certificates. This should not be used in live environments.
-                        o.WithCertificateValidationHandler(_ => true);
+                        o.CertificateValidationHandler = _ => true;
 
                         // The default value is determined by the OS. Set manually to force version.
-                        o.WithSslProtocols(SslProtocols.Tls12);
+                        o.SslProtocol = SslProtocols.Tls12;
                     })
                 .Build();
 
@@ -273,7 +196,7 @@ public static class Client_Connection_Samples
 
         using (var mqttClient = mqttFactory.CreateMqttClient())
         {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.hivemq.com:8000/mqtt")).Build();
+            var mqttClientOptions = new MqttClientOptionsBuilder().WithWebSocketServer("broker.hivemq.com:8000/mqtt").Build();
 
             var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
 
@@ -295,7 +218,7 @@ public static class Client_Connection_Samples
 
         using (var mqttClient = mqttFactory.CreateMqttClient())
         {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.hivemq.com:8000/mqtt")).Build();
+            var mqttClientOptions = new MqttClientOptionsBuilder().WithWebSocketServer("broker.hivemq.com:8000/mqtt").Build();
 
             var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
 
@@ -318,11 +241,13 @@ public static class Client_Connection_Samples
         using (var mqttClient = mqttFactory.CreateMqttClient())
         {
             var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8883)
-                .WithTlsOptions(
-                    o => o.WithCertificateValidationHandler(
+                .WithTls(
+                    o =>
+                    {
                         // The used public broker sometimes has invalid certificates. This sample accepts all
                         // certificates. This should not be used in live environments.
-                        _ => true))
+                        o.CertificateValidationHandler = _ => true;
+                    })
                 .Build();
 
             // In MQTTv5 the response contains much more information.
@@ -337,31 +262,6 @@ public static class Client_Connection_Samples
         }
     }
 
-    public static async Task Connect_With_Amazon_AWS()
-    {
-        /*
-         * This sample creates a simple MQTT client and connects to an Amazon Web Services broker.
-         *
-         * The broker requires special settings which are set here.
-         */
-
-        var mqttFactory = new MqttFactory();
-
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("amazon.web.services.broker")
-                // Disabling packet fragmentation is very important!  
-                .WithoutPacketFragmentation()
-                .Build();
-
-            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
-
-            Console.WriteLine("The MQTT client is connected.");
-
-            await mqttClient.DisconnectAsync();
-        }
-    }
-
     public static async Task Disconnect_Clean()
     {
         /*
@@ -417,19 +317,18 @@ public static class Client_Connection_Samples
         using (var mqttClient = mqttFactory.CreateMqttClient())
         {
             var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("mqtt.fluux.io", 8883)
-                .WithTlsOptions(
+                .WithTls(
                     o =>
                     {
-                        o.WithCertificateValidationHandler(
-                            eventArgs =>
-                            {
-                                eventArgs.Certificate.Subject.DumpToConsole();
-                                eventArgs.Certificate.GetExpirationDateString().DumpToConsole();
-                                eventArgs.Chain.ChainPolicy.RevocationMode.DumpToConsole();
-                                eventArgs.Chain.ChainStatus.DumpToConsole();
-                                eventArgs.SslPolicyErrors.DumpToConsole();
-                                return true;
-                            });
+                        o.CertificateValidationHandler = eventArgs =>
+                        {
+                            eventArgs.Certificate.Subject.DumpToConsole();
+                            eventArgs.Certificate.GetExpirationDateString().DumpToConsole();
+                            eventArgs.Chain.ChainPolicy.RevocationMode.DumpToConsole();
+                            eventArgs.Chain.ChainStatus.DumpToConsole();
+                            eventArgs.SslPolicyErrors.DumpToConsole();
+                            return true;
+                        };
                     })
                 .Build();
 
@@ -533,59 +432,6 @@ public static class Client_Connection_Samples
                         }
                     }
                 });
-
-            Console.WriteLine("Press <Enter> to exit");
-            Console.ReadLine();
         }
     }
-
-    public static async Task ConnectTls_WithCaFile()
-    {
-        var mqttFactory = new MqttFactory();
-
-        X509Certificate2Collection caChain = new X509Certificate2Collection();
-        caChain.ImportFromPem(mosquitto_org); // from https://test.mosquitto.org/ssl/mosquitto.org.crt
-
-        using (var mqttClient = mqttFactory.CreateMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder()
-                .WithTcpServer("test.mosquitto.org", 8883)
-                .WithTlsOptions(new MqttClientTlsOptionsBuilder()
-                    .WithTrustChain(caChain) 
-                    .Build())
-                .Build();
-
-            var connAck = await mqttClient.ConnectAsync(mqttClientOptions);
-            Console.WriteLine("Connected to test.moquitto.org:8883 with CaFile mosquitto.org.crt: " + connAck.ResultCode);
-        }
-
-
-    }
-    const string mosquitto_org = @"
------BEGIN CERTIFICATE-----
-MIIEAzCCAuugAwIBAgIUBY1hlCGvdj4NhBXkZ/uLUZNILAwwDQYJKoZIhvcNAQEL
-BQAwgZAxCzAJBgNVBAYTAkdCMRcwFQYDVQQIDA5Vbml0ZWQgS2luZ2RvbTEOMAwG
-A1UEBwwFRGVyYnkxEjAQBgNVBAoMCU1vc3F1aXR0bzELMAkGA1UECwwCQ0ExFjAU
-BgNVBAMMDW1vc3F1aXR0by5vcmcxHzAdBgkqhkiG9w0BCQEWEHJvZ2VyQGF0Y2hv
-by5vcmcwHhcNMjAwNjA5MTEwNjM5WhcNMzAwNjA3MTEwNjM5WjCBkDELMAkGA1UE
-BhMCR0IxFzAVBgNVBAgMDlVuaXRlZCBLaW5nZG9tMQ4wDAYDVQQHDAVEZXJieTES
-MBAGA1UECgwJTW9zcXVpdHRvMQswCQYDVQQLDAJDQTEWMBQGA1UEAwwNbW9zcXVp
-dHRvLm9yZzEfMB0GCSqGSIb3DQEJARYQcm9nZXJAYXRjaG9vLm9yZzCCASIwDQYJ
-KoZIhvcNAQEBBQADggEPADCCAQoCggEBAME0HKmIzfTOwkKLT3THHe+ObdizamPg
-UZmD64Tf3zJdNeYGYn4CEXbyP6fy3tWc8S2boW6dzrH8SdFf9uo320GJA9B7U1FW
-Te3xda/Lm3JFfaHjkWw7jBwcauQZjpGINHapHRlpiCZsquAthOgxW9SgDgYlGzEA
-s06pkEFiMw+qDfLo/sxFKB6vQlFekMeCymjLCbNwPJyqyhFmPWwio/PDMruBTzPH
-3cioBnrJWKXc3OjXdLGFJOfj7pP0j/dr2LH72eSvv3PQQFl90CZPFhrCUcRHSSxo
-E6yjGOdnz7f6PveLIB574kQORwt8ePn0yidrTC1ictikED3nHYhMUOUCAwEAAaNT
-MFEwHQYDVR0OBBYEFPVV6xBUFPiGKDyo5V3+Hbh4N9YSMB8GA1UdIwQYMBaAFPVV
-6xBUFPiGKDyo5V3+Hbh4N9YSMA8GA1UdEwEB/wQFMAMBAf8wDQYJKoZIhvcNAQEL
-BQADggEBAGa9kS21N70ThM6/Hj9D7mbVxKLBjVWe2TPsGfbl3rEDfZ+OKRZ2j6AC
-6r7jb4TZO3dzF2p6dgbrlU71Y/4K0TdzIjRj3cQ3KSm41JvUQ0hZ/c04iGDg/xWf
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-m/XriWr/Cq4h/JfB7NTsezVslgkBaoU=
------END CERTIFICATE-----
-";
-
-}
+}

Samples/Client/Client_Subscribe_Samples.cs

@@ -5,10 +5,9 @@
 // ReSharper disable UnusedType.Global
 // ReSharper disable UnusedMember.Global
 // ReSharper disable InconsistentNaming
-// ReSharper disable UnusedMember.Local
 
+using MQTTnet;
 using MQTTnet.Client;
-using MQTTnet.Extensions.TopicTemplate;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
 using MQTTnet.Samples.Helpers;
@@ -17,8 +16,6 @@ namespace MQTTnet.Samples.Client;
 
 public static class Client_Subscribe_Samples
 {
-    static MqttTopicTemplate sampleTemplate = new MqttTopicTemplate("mqttnet/samples/topic/{id}");
-    
     public static async Task Handle_Received_Application_Message()
     {
         /*
@@ -45,7 +42,11 @@ public static class Client_Subscribe_Samples
             await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
 
             var mqttSubscribeOptions = mqttFactory.CreateSubscribeOptionsBuilder()
-                .WithTopicTemplate(sampleTemplate.WithParameter("id", "2"))
+                .WithTopicFilter(
+                    f =>
+                    {
+                        f.WithTopic("mqttnet/samples/topic/2");
+                    })
                 .Build();
 
             await mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
@@ -87,8 +88,11 @@ public static class Client_Subscribe_Samples
             await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
 
             var mqttSubscribeOptions = mqttFactory.CreateSubscribeOptionsBuilder()
-                .WithTopicTemplate(
-                    sampleTemplate.WithParameter("id", "1"))
+                .WithTopicFilter(
+                    f =>
+                    {
+                        f.WithTopic("mqttnet/samples/topic/1");
+                    })
                 .Build();
 
             var response = await mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
@@ -117,12 +121,21 @@ public static class Client_Subscribe_Samples
             // Create the subscribe options including several topics with different options.
             // It is also possible to all of these topics using a dedicated call of _SubscribeAsync_ per topic.
             var mqttSubscribeOptions = mqttFactory.CreateSubscribeOptionsBuilder()
-                .WithTopicTemplate(
-                    sampleTemplate.WithParameter("id", "1"))
-                .WithTopicTemplate(
-                    sampleTemplate.WithParameter("id", "2"), noLocal: true)
-                .WithTopicTemplate(
-                    sampleTemplate.WithParameter("id", "3"), retainHandling: MqttRetainHandling.SendAtSubscribe)
+                .WithTopicFilter(
+                    f =>
+                    {
+                        f.WithTopic("mqttnet/samples/topic/1");
+                    })
+                .WithTopicFilter(
+                    f =>
+                    {
+                        f.WithTopic("mqttnet/samples/topic/2").WithNoLocal();
+                    })
+                .WithTopicFilter(
+                    f =>
+                    {
+                        f.WithTopic("mqttnet/samples/topic/3").WithRetainHandling(MqttRetainHandling.SendAtSubscribe);
+                    })
                 .Build();
 
             var response = await mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
@@ -149,7 +162,11 @@ public static class Client_Subscribe_Samples
             await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
 
             var mqttSubscribeOptions = mqttFactory.CreateSubscribeOptionsBuilder()
-                .WithTopicTemplate(sampleTemplate.WithParameter("id", "1"))
+                .WithTopicFilter(
+                    f =>
+                    {
+                        f.WithTopic("mqttnet/samples/topic/1");
+                    })
                 .Build();
 
             var response = await mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
@@ -160,62 +177,4 @@ public static class Client_Subscribe_Samples
             response.DumpToConsole();
         }
     }
-
-    static void ConcurrentProcessingDisableAutoAcknowledge(CancellationToken shutdownToken, IMqttClient mqttClient)
-    {
-        /*
-         * This sample shows how to achieve concurrent processing and not have message AutoAcknowledged
-         * This to have a proper QoS1 (at-least-once) experience for what at least MQTT specification can provide
-         */
-        mqttClient.ApplicationMessageReceivedAsync += ea =>
-        {
-            ea.AutoAcknowledge = false;
-
-            async Task ProcessAsync()
-            {
-                // DO YOUR WORK HERE!
-                await Task.Delay(1000, shutdownToken);
-                await ea.AcknowledgeAsync(shutdownToken);
-                // WARNING: If process failures are not transient the message will be retried on every restart of the client
-                //          A failed message will not be dispatched again to the client as MQTT does not have a NACK packet to let
-                //          the broker know processing failed
-                //
-                // Optionally: Use a framework like Polly to create a retry policy: https://github.com/App-vNext/Polly#retry
-            }
-
-            _ = Task.Run(ProcessAsync, shutdownToken);
-
-            return Task.CompletedTask;
-        };
-    }
-
-    static void ConcurrentProcessingWithLimit(CancellationToken shutdownToken, IMqttClient mqttClient)
-    {
-        /*
-         * This sample shows how to achieve concurrent processing, with:
-         * - a maximum concurrency limit based on Environment.ProcessorCount
-         */
-
-        var concurrent = new SemaphoreSlim(Environment.ProcessorCount);
-
-        mqttClient.ApplicationMessageReceivedAsync += async ea =>
-        {
-            await concurrent.WaitAsync(shutdownToken).ConfigureAwait(false);
-
-            async Task ProcessAsync()
-            {
-                try
-                {
-                    // DO YOUR WORK HERE!
-                    await Task.Delay(1000, shutdownToken);
-                }
-                finally
-                {
-                    concurrent.Release();
-                }
-            }
-
-            _ = Task.Run(ProcessAsync, shutdownToken);
-        };
-    }
-}
+}

Samples/MQTTnet.Samples.csproj

@@ -2,7 +2,7 @@
 
     <PropertyGroup>
         <OutputType>Exe</OutputType>
-        <TargetFramework>net7.0</TargetFramework>
+        <TargetFramework>net6.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
         <IsPackable>false</IsPackable>
@@ -17,7 +17,6 @@
         <ProjectReference Include="..\Source\MQTTnet.AspnetCore\MQTTnet.AspNetCore.csproj" />
         <ProjectReference Include="..\Source\MQTTnet.Extensions.ManagedClient\MQTTnet.Extensions.ManagedClient.csproj" />
         <ProjectReference Include="..\Source\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj" />
-        <ProjectReference Include="..\Source\MQTTnet.Extensions.TopicTemplate\MQTTnet.Extensions.TopicTemplate.csproj" />
         <ProjectReference Include="..\Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj" />
         <ProjectReference Include="..\Source\MQTTnet\MQTTnet.csproj" />
     </ItemGroup>

Samples/ManagedClient/Managed_Client_Subscribe_Samples.cs

@@ -1,87 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-// ReSharper disable UnusedType.Global
-// ReSharper disable UnusedMember.Global
-// ReSharper disable InconsistentNaming
-
-using MQTTnet.Client;
-using MQTTnet.Extensions.ManagedClient;
-
-namespace MQTTnet.Samples.ManagedClient;
-
-public sealed class Managed_Client_Subscribe_Samples
-{
-    public static async Task Connect_Client()
-    {
-        /*
-         * This sample creates a simple managed MQTT client and connects to a public broker, subscribe to a topic and verifies subscription result.
-         *
-         * The managed client extends the existing _MqttClient_. It adds the following features.
-         * - Reconnecting when connection is lost.
-         * - Storing pending messages in an internal queue so that an enqueue is possible while the client remains not connected.
-         */
-
-        var mqttFactory = new MqttFactory();
-        var subscribed = false;
-
-        using (var managedMqttClient = mqttFactory.CreateManagedMqttClient())
-        {
-            var mqttClientOptions = new MqttClientOptionsBuilder()
-                .WithTcpServer("broker.hivemq.com")
-                .Build();
-
-            var managedMqttClientOptions = new ManagedMqttClientOptionsBuilder()
-                .WithClientOptions(mqttClientOptions)
-                .Build();
-
-            await managedMqttClient.StartAsync(managedMqttClientOptions);
-
-            // The application message is not sent. It is stored in an internal queue and
-            // will be sent when the client is connected.
-            await managedMqttClient.EnqueueAsync("Topic", "Payload");
-
-            Console.WriteLine("The managed MQTT client is connected.");
-
-            // Wait until the queue is fully processed.
-            SpinWait.SpinUntil(() => managedMqttClient.PendingApplicationMessagesCount == 0, 10000);
-
-            Console.WriteLine($"Pending messages = {managedMqttClient.PendingApplicationMessagesCount}");
-
-            managedMqttClient.SubscriptionsChangedAsync += args => SubscriptionsResultAsync(args, ref subscribed);
-            await managedMqttClient.SubscribeAsync("Topic").ConfigureAwait(false);
-
-            SpinWait.SpinUntil(() => subscribed, 1000);
-            Console.WriteLine($"Subscription properly done {subscribed}");
-        }
-    }
-
-    private static Task SubscriptionsResultAsync(SubscriptionsChangedEventArgs arg, ref bool subscribed)
-    {
-        foreach (var mqttClientSubscribeResult in arg.SubscribeResult)
-        {
-            Console.WriteLine($"Subscription reason {mqttClientSubscribeResult.ReasonString}");
-            foreach (var item in mqttClientSubscribeResult.Items)
-            {
-                Console.WriteLine($"For topic filter {item.TopicFilter}, result code: {item.ResultCode}");
-
-                if (item.TopicFilter.Topic == "Topic" && item.ResultCode == MqttClientSubscribeResultCode.GrantedQoS0 && !subscribed)
-                {
-                    subscribed = true;
-                }
-            }
-        }
-
-        foreach (var mqttClientUnsubscribeResult in arg.UnsubscribeResult)
-        {
-            Console.WriteLine($"Unsubscription reason {mqttClientUnsubscribeResult.ReasonString}");
-            foreach (var item in mqttClientUnsubscribeResult.Items)
-            {
-                Console.WriteLine($"For topic filter {item.TopicFilter}, result code: {item.ResultCode}");
-            }
-        }
-
-        return Task.CompletedTask;
-    }
-}

Source/MQTTnet.AspNetCore.Tests/MqttConnectionContextTest.cs

@@ -48,6 +48,7 @@ namespace MQTTnet.AspNetCore.Tests
         {
             var mockup = new ConnectionHandlerMockup();
 
+
             using (var host = new WebHostBuilder().UseKestrel(kestrel => kestrel.ListenLocalhost(1883, listener => listener.Use((ctx, next) => mockup.OnConnectedAsync(ctx))))
                        .UseStartup<Startup>()
                        .ConfigureServices(

Source/MQTTnet.AspTestApp/MQTTnet.AspTestApp.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
     <PropertyGroup>
-        <TargetFramework>net7.0</TargetFramework>
+        <TargetFramework>net6.0</TargetFramework>
         <Nullable>enable</Nullable>
         <ImplicitUsings>enable</ImplicitUsings>
         <IsPackable>false</IsPackable>

Source/MQTTnet.AspnetCore/Client/MqttClientConnectionContextFactory.cs

@@ -6,6 +6,7 @@ using MQTTnet.Adapter;
 using MQTTnet.AspNetCore.Client.Tcp;
 using MQTTnet.Formatter;
 using System;
+using System.Net;
 using MQTTnet.Client;
 using MQTTnet.Diagnostics;
 
@@ -21,7 +22,8 @@ namespace MQTTnet.AspNetCore.Client
             {
                 case MqttClientTcpOptions tcpOptions:
                     {
-                        var tcpConnection = new SocketConnection(tcpOptions.RemoteEndpoint);
+                        var endpoint = new DnsEndPoint(tcpOptions.Server, tcpOptions.GetPort());
+                        var tcpConnection = new TcpConnection(endpoint);
                         
                         var formatter = new MqttPacketFormatterAdapter(options.ProtocolVersion, new MqttBufferWriter(4096, 65535));
                         return new MqttConnectionContext(formatter, tcpConnection);

Source/MQTTnet.AspnetCore/Client/Tcp/TcpConnection.cs

@@ -15,15 +15,15 @@ using System.Threading.Tasks;
 
 namespace MQTTnet.AspNetCore.Client.Tcp
 {
-    public sealed class SocketConnection : ConnectionContext
+    public class TcpConnection : ConnectionContext
     {
-        volatile bool _aborted;
-        readonly EndPoint _endPoint;
-        SocketSender _sender;
-        SocketReceiver _receiver;
+        private volatile bool _aborted;
+        private readonly EndPoint _endPoint;
+        private SocketSender _sender;
+        private SocketReceiver _receiver;
 
-        Socket _socket;
-        IDuplexPipe _application;
+        private Socket _socket;
+        private IDuplexPipe _application;
 
         public bool IsConnected { get; private set; }
         public override string ConnectionId { get; set; }
@@ -31,12 +31,12 @@ namespace MQTTnet.AspNetCore.Client.Tcp
         public override IDictionary<object, object> Items { get; set; }
         public override IDuplexPipe Transport { get; set; }
 
-        public SocketConnection(EndPoint endPoint)
+        public TcpConnection(EndPoint endPoint)
         {
             _endPoint = endPoint;
         }
 
-        public SocketConnection(Socket socket)
+        public TcpConnection(Socket socket)
         {
             _socket = socket;
             _endPoint = socket.RemoteEndPoint;
@@ -87,7 +87,7 @@ namespace MQTTnet.AspNetCore.Client.Tcp
             IsConnected = true;
         }
 
-        async Task ExecuteAsync()
+        private async Task ExecuteAsync()
         {
             Exception sendError = null;
             try
@@ -114,7 +114,7 @@ namespace MQTTnet.AspNetCore.Client.Tcp
             }
             catch (Exception ex)
             {
-                Console.WriteLine($"Unexpected exception in {nameof(SocketConnection)}.{nameof(StartAsync)}: " + ex);
+                Console.WriteLine($"Unexpected exception in {nameof(TcpConnection)}.{nameof(StartAsync)}: " + ex);
             }
             finally
             {
@@ -122,8 +122,7 @@ namespace MQTTnet.AspNetCore.Client.Tcp
                 _application.Input.Complete(sendError);
             }
         }
-
-        async Task DoReceive()
+        private async Task DoReceive()
         {
             Exception error = null;
 
@@ -172,7 +171,7 @@ namespace MQTTnet.AspNetCore.Client.Tcp
             }
         }
 
-        async Task ProcessReceives()
+        private async Task ProcessReceives()
         {
             while (true)
             {
@@ -205,12 +204,12 @@ namespace MQTTnet.AspNetCore.Client.Tcp
             }
         }
 
-        Exception ConnectionAborted()
+        private Exception ConnectionAborted()
         {
             return new MqttCommunicationException("Connection Aborted");
         }
 
-        async Task<Exception> DoSend()
+        private async Task<Exception> DoSend()
         {
             Exception error = null;
 
@@ -241,7 +240,7 @@ namespace MQTTnet.AspNetCore.Client.Tcp
             return error;
         }
 
-        async Task ProcessSends()
+        private async Task ProcessSends()
         {
             while (true)
             {

Source/MQTTnet.AspnetCore/MQTTnet.AspNetCore.csproj

@@ -42,7 +42,7 @@
             <PackagePath>\</PackagePath>
         </None>
     </ItemGroup>
-
+    
     <ItemGroup>
         <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
     </ItemGroup>
@@ -51,11 +51,11 @@
         <DefineConstants>RELEASE;NETSTANDARD2_0</DefineConstants>
     </PropertyGroup>
 
-    <ItemGroup Condition="'$(TargetFramework)' != 'netstandard2.0' and '$(TargetFramework)' != 'netcoreapp2.1' ">
+    <ItemGroup Condition="'$(TargetFramework)' == 'netcoreapp3.1' or '$(TargetFramework)' == 'net5.0' or '$(TargetFramework)' == 'net6.0' or '$(TargetFramework)' == 'net7.0' ">
         <FrameworkReference Include="Microsoft.AspNetCore.App" />
     </ItemGroup>
 
-    <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'netcoreapp2.1' ">
+    <ItemGroup Condition="'$(TargetFramework)' != 'netcoreapp3.1' and '$(TargetFramework)' != 'net5.0' and '$(TargetFramework)' != 'net6.0' and '$(TargetFramework)' != 'net7.0' ">
         <PackageReference Include="Microsoft.AspNetCore.Http.Connections" Version="1.1.0" />
     </ItemGroup>
 

Source/MQTTnet.AspnetCore/MqttConnectionContext.cs

@@ -33,11 +33,8 @@ namespace MQTTnet.AspNetCore
             PacketFormatterAdapter = packetFormatterAdapter ?? throw new ArgumentNullException(nameof(packetFormatterAdapter));
             _connection = connection ?? throw new ArgumentNullException(nameof(connection));
 
-            if (!(_connection is SocketConnection tcp) || tcp.IsConnected)
-            {
-                _input = connection.Transport.Input;
-                _output = connection.Transport.Output;
-            }
+            _input = connection.Transport.Input;
+            _output = connection.Transport.Output;
         }
 
         public long BytesReceived { get; private set; }
@@ -83,6 +80,8 @@ namespace MQTTnet.AspNetCore
             }
         }
 
+        public bool IsReadingPacket { get; private set; }
+
         public bool IsSecureConnection
         {
             get
@@ -109,7 +108,7 @@ namespace MQTTnet.AspNetCore
 
         public async Task ConnectAsync(CancellationToken cancellationToken)
         {
-            if (_connection is SocketConnection tcp && !tcp.IsConnected)
+            if (_connection is TcpConnection tcp && !tcp.IsConnected)
             {
                 await tcp.StartAsync().ConfigureAwait(false);
             }
@@ -162,6 +161,11 @@ namespace MQTTnet.AspNetCore
                                 BytesReceived += received;
                                 return packet;
                             }
+                            else
+                            {
+                                // we did receive something but the message is not yet complete
+                                IsReadingPacket = true;
+                            }
                         }
                         else if (readResult.IsCompleted)
                         {
@@ -182,9 +186,12 @@ namespace MQTTnet.AspNetCore
                 // completing the channel makes sure that there is no more data read after a protocol error
                 _input?.Complete(exception);
                 _output?.Complete(exception);
-
                 throw;
             }
+            finally
+            {
+                IsReadingPacket = false;
+            }
 
             cancellationToken.ThrowIfCancellationRequested();
             return null;

Source/MQTTnet.AspnetCore/MqttHostedServer.cs

@@ -2,7 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
@@ -15,52 +14,20 @@ namespace MQTTnet.AspNetCore
 {
     public sealed class MqttHostedServer : MqttServer, IHostedService
     {
-        readonly MqttFactory _mqttFactory;
-#if NETCOREAPP3_1_OR_GREATER
-        readonly IHostApplicationLifetime _hostApplicationLifetime;
-        public MqttHostedServer(IHostApplicationLifetime hostApplicationLifetime, MqttFactory mqttFactory,
-            MqttServerOptions options, IEnumerable<IMqttServerAdapter> adapters, IMqttNetLogger logger) : base(
-            options,
-            adapters,
-            logger)
+        public MqttHostedServer(MqttServerOptions options, IEnumerable<IMqttServerAdapter> adapters, IMqttNetLogger logger) 
+            : base(options, adapters, logger)
         {
-            _mqttFactory = mqttFactory ?? throw new ArgumentNullException(nameof(mqttFactory));
-            _hostApplicationLifetime = hostApplicationLifetime;
         }
-#else
-        public MqttHostedServer(MqttFactory mqttFactory,
-            MqttServerOptions options, IEnumerable<IMqttServerAdapter> adapters, IMqttNetLogger logger) : base(
-            options,
-            adapters,
-            logger)
+
+        public Task StartAsync(CancellationToken cancellationToken)
         {
-            _mqttFactory = mqttFactory ?? throw new ArgumentNullException(nameof(mqttFactory));
-        }
-#endif
-
-
-        public async Task StartAsync(CancellationToken cancellationToken)
-        {
-            // The yield makes sure that the hosted service is considered up and running.
-            await Task.Yield();
-#if NETCOREAPP3_1_OR_GREATER
-            _hostApplicationLifetime.ApplicationStarted.Register(OnStarted);
-#else
-            _ = StartAsync();
-#endif
-
+            _ =  StartAsync();
+            return Task.CompletedTask;
         }
 
         public Task StopAsync(CancellationToken cancellationToken)
         {
-            return StopAsync(_mqttFactory.CreateMqttServerStopOptionsBuilder().Build());
+            return StopAsync();
         }
-
-#if NETCOREAPP3_1_OR_GREATER
-        private void OnStarted()
-        {
-            _ = StartAsync();
-        }
-#endif
     }
 }

Source/MQTTnet.AspnetCore/ServiceCollectionExtensions.cs

@@ -4,7 +4,6 @@
 
 using System;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Hosting;
 using MQTTnet.Adapter;
 using MQTTnet.Diagnostics;
@@ -15,89 +14,6 @@ namespace MQTTnet.AspNetCore
 {
     public static class ServiceCollectionExtensions
     {
-        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, MqttServerOptions options)
-        {
-            if (services == null)
-            {
-                throw new ArgumentNullException(nameof(services));
-            }
-
-            if (options == null)
-            {
-                throw new ArgumentNullException(nameof(options));
-            }
-
-            services.AddSingleton(options);
-            services.AddHostedMqttServer();
-
-            return services;
-        }
-
-        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, Action<MqttServerOptionsBuilder> configure)
-        {
-            if (services == null)
-            {
-                throw new ArgumentNullException(nameof(services));
-            }
-
-            var serverOptionsBuilder = new MqttServerOptionsBuilder();
-
-            configure?.Invoke(serverOptionsBuilder);
-
-            var options = serverOptionsBuilder.Build();
-
-            return AddHostedMqttServer(services, options);
-        }
-
-        public static void AddHostedMqttServer(this IServiceCollection services)
-        {
-            // The user may have these services already registered.
-            services.TryAddSingleton<IMqttNetLogger>(MqttNetNullLogger.Instance);
-            services.TryAddSingleton(new MqttFactory());
-
-            services.AddSingleton<MqttHostedServer>();
-            services.AddSingleton<IHostedService>(s => s.GetService<MqttHostedServer>());
-            services.AddSingleton<MqttServer>(s => s.GetService<MqttHostedServer>());
-        }
-
-        public static IServiceCollection AddHostedMqttServerWithServices(this IServiceCollection services, Action<AspNetMqttServerOptionsBuilder> configure)
-        {
-            if (services == null)
-            {
-                throw new ArgumentNullException(nameof(services));
-            }
-
-            services.AddSingleton(
-                s =>
-                {
-                    var builder = new AspNetMqttServerOptionsBuilder(s);
-                    configure(builder);
-                    return builder.Build();
-                });
-
-            services.AddHostedMqttServer();
-
-            return services;
-        }
-
-        public static IServiceCollection AddMqttConnectionHandler(this IServiceCollection services)
-        {
-            services.AddSingleton<MqttConnectionHandler>();
-            services.AddSingleton<IMqttServerAdapter>(s => s.GetService<MqttConnectionHandler>());
-
-            return services;
-        }
-
-        public static void AddMqttLogger(this IServiceCollection services, IMqttNetLogger logger)
-        {
-            if (services == null)
-            {
-                throw new ArgumentNullException(nameof(services));
-            }
-
-            services.AddSingleton(logger);
-        }
-
         public static IServiceCollection AddMqttServer(this IServiceCollection serviceCollection, Action<MqttServerOptionsBuilder> configure = null)
         {
             if (serviceCollection is null)
@@ -107,14 +23,57 @@ namespace MQTTnet.AspNetCore
 
             serviceCollection.AddMqttConnectionHandler();
             serviceCollection.AddHostedMqttServer(configure);
-
+            
             return serviceCollection;
         }
 
-        public static IServiceCollection AddMqttTcpServerAdapter(this IServiceCollection services)
+        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, MqttServerOptions options)
         {
-            services.AddSingleton<MqttTcpServerAdapter>();
-            services.AddSingleton<IMqttServerAdapter>(s => s.GetService<MqttTcpServerAdapter>());
+            if (options == null) throw new ArgumentNullException(nameof(options));
+
+            services.AddSingleton(options);
+
+            services.AddHostedMqttServer();
+
+            return services;
+        }
+
+        public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, Action<MqttServerOptionsBuilder> configure = null)
+        {
+            services.AddSingleton(s =>
+            {
+                var serverOptionsBuilder = new MqttServerOptionsBuilder();
+                configure?.Invoke(serverOptionsBuilder);
+                return serverOptionsBuilder.Build();
+            });
+
+            services.AddHostedMqttServer();
+
+            return services;
+        }
+
+        public static IServiceCollection AddHostedMqttServerWithServices(this IServiceCollection services, Action<AspNetMqttServerOptionsBuilder> configure)
+        {
+            services.AddSingleton(s =>
+            {
+                var builder = new AspNetMqttServerOptionsBuilder(s);
+                configure(builder);
+                return builder.Build();
+            });
+
+            services.AddHostedMqttServer();
+
+            return services;
+        }
+
+        static IServiceCollection AddHostedMqttServer(this IServiceCollection services)
+        {
+            var logger = new MqttNetEventLogger();
+
+            services.AddSingleton<IMqttNetLogger>(logger);
+            services.AddSingleton<MqttHostedServer>();
+            services.AddSingleton<IHostedService>(s => s.GetService<MqttHostedServer>());
+            services.AddSingleton<MqttServer>(s => s.GetService<MqttHostedServer>());
 
             return services;
         }
@@ -126,5 +85,21 @@ namespace MQTTnet.AspNetCore
 
             return services;
         }
+
+        public static IServiceCollection AddMqttTcpServerAdapter(this IServiceCollection services)
+        {
+            services.AddSingleton<MqttTcpServerAdapter>();
+            services.AddSingleton<IMqttServerAdapter>(s => s.GetService<MqttTcpServerAdapter>());
+
+            return services;
+        }
+
+        public static IServiceCollection AddMqttConnectionHandler(this IServiceCollection services)
+        {
+            services.AddSingleton<MqttConnectionHandler>();
+            services.AddSingleton<IMqttServerAdapter>(s => s.GetService<MqttConnectionHandler>());
+
+            return services;
+        }
     }
-}
+}

Source/MQTTnet.Benchmarks/TcpPipesBenchmark.cs

@@ -29,12 +29,12 @@ namespace MQTTnet.Benchmarks
 
             var task = Task.Run(() => server.AcceptSocket());
 
-            var clientConnection = new SocketConnection(new IPEndPoint(IPAddress.Loopback, 1883));
+            var clientConnection = new TcpConnection(new IPEndPoint(IPAddress.Loopback, 1883));
 
             clientConnection.StartAsync().GetAwaiter().GetResult();
             _client = clientConnection.Transport;
 
-            var serverConnection = new SocketConnection(task.GetAwaiter().GetResult());
+            var serverConnection = new TcpConnection(task.GetAwaiter().GetResult());
             serverConnection.StartAsync().GetAwaiter().GetResult();
             _server = serverConnection.Transport;
         }

Source/MQTTnet.Extensions.ManagedClient/IManagedMqttClient.cs

@@ -25,8 +25,6 @@ namespace MQTTnet.Extensions.ManagedClient
         
         event Func<ManagedProcessFailedEventArgs, Task> SynchronizingSubscriptionsFailedAsync;
         
-        event Func<SubscriptionsChangedEventArgs, Task> SubscriptionsChangedAsync;
-        
         IMqttClient InternalClient { get; }
         
         bool IsConnected { get; }
@@ -47,8 +45,8 @@ namespace MQTTnet.Extensions.ManagedClient
         
         Task StopAsync(bool cleanDisconnect = true);
         
-        Task SubscribeAsync(IEnumerable<MqttTopicFilter> topicFilters);
+        Task SubscribeAsync(ICollection<MqttTopicFilter> topicFilters);
         
-        Task UnsubscribeAsync(IEnumerable<string> topics);
+        Task UnsubscribeAsync(ICollection<string> topics);
     }
 }

Source/MQTTnet.Extensions.ManagedClient/InterceptingPublishMessageEventArgs.cs

@@ -1,20 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public sealed class InterceptingPublishMessageEventArgs : EventArgs
-    {
-        public InterceptingPublishMessageEventArgs(ManagedMqttApplicationMessage applicationMessage)
-        {
-            ApplicationMessage = applicationMessage ?? throw new ArgumentNullException(nameof(applicationMessage));
-        }
-
-        public ManagedMqttApplicationMessage ApplicationMessage { get; }
-
-        public bool AcceptPublish { get; set; } = true;
-    }
-}

Source/MQTTnet.Extensions.ManagedClient/ManagedMqttClient.cs

@@ -19,17 +19,15 @@ namespace MQTTnet.Extensions.ManagedClient
 {
     public sealed class ManagedMqttClient : Disposable, IManagedMqttClient
     {
-        readonly MqttNetSourceLogger _logger;
-
-        readonly AsyncEvent<InterceptingPublishMessageEventArgs> _interceptingPublishMessageEvent = new AsyncEvent<InterceptingPublishMessageEventArgs>();
         readonly AsyncEvent<ApplicationMessageProcessedEventArgs> _applicationMessageProcessedEvent = new AsyncEvent<ApplicationMessageProcessedEventArgs>();
         readonly AsyncEvent<ApplicationMessageSkippedEventArgs> _applicationMessageSkippedEvent = new AsyncEvent<ApplicationMessageSkippedEventArgs>();
         readonly AsyncEvent<ConnectingFailedEventArgs> _connectingFailedEvent = new AsyncEvent<ConnectingFailedEventArgs>();
         readonly AsyncEvent<EventArgs> _connectionStateChangedEvent = new AsyncEvent<EventArgs>();
         readonly AsyncEvent<ManagedProcessFailedEventArgs> _synchronizingSubscriptionsFailedEvent = new AsyncEvent<ManagedProcessFailedEventArgs>();
-        readonly AsyncEvent<SubscriptionsChangedEventArgs> _subscriptionsChangedEvent = new AsyncEvent<SubscriptionsChangedEventArgs>();
-
+        
+        readonly MqttNetSourceLogger _logger;
         readonly BlockingQueue<ManagedMqttApplicationMessage> _messageQueue = new BlockingQueue<ManagedMqttApplicationMessage>();
+
         readonly AsyncLock _messageQueueLock = new AsyncLock();
 
         /// <summary>
@@ -83,19 +81,13 @@ namespace MQTTnet.Extensions.ManagedClient
             add => _applicationMessageSkippedEvent.AddHandler(value);
             remove => _applicationMessageSkippedEvent.RemoveHandler(value);
         }
-
+        
         public event Func<ApplicationMessageProcessedEventArgs, Task> ApplicationMessageProcessedAsync
         {
             add => _applicationMessageProcessedEvent.AddHandler(value);
             remove => _applicationMessageProcessedEvent.RemoveHandler(value);
         }
 
-        public event Func<InterceptingPublishMessageEventArgs, Task> InterceptPublishMessageAsync
-        {
-            add => _interceptingPublishMessageEvent.AddHandler(value);
-            remove => _interceptingPublishMessageEvent.RemoveHandler(value);
-        }
-
         public event Func<MqttApplicationMessageReceivedEventArgs, Task> ApplicationMessageReceivedAsync
         {
             add => InternalClient.ApplicationMessageReceivedAsync += value;
@@ -132,12 +124,6 @@ namespace MQTTnet.Extensions.ManagedClient
             remove => _synchronizingSubscriptionsFailedEvent.RemoveHandler(value);
         }
 
-        public event Func<SubscriptionsChangedEventArgs, Task> SubscriptionsChangedAsync
-        {
-            add => _subscriptionsChangedEvent.AddHandler(value);
-            remove => _subscriptionsChangedEvent.RemoveHandler(value);
-        }
-
         public IMqttClient InternalClient { get; }
 
         public bool IsConnected => InternalClient.IsConnected;
@@ -147,7 +133,7 @@ namespace MQTTnet.Extensions.ManagedClient
         public ManagedMqttClientOptions Options { get; private set; }
 
         public int PendingApplicationMessagesCount => _messageQueue.Count;
-
+        
         public async Task EnqueueAsync(MqttApplicationMessage applicationMessage)
         {
             ThrowIfDisposed();
@@ -275,7 +261,7 @@ namespace MQTTnet.Extensions.ManagedClient
             ThrowIfDisposed();
 
             _isCleanDisconnect = cleanDisconnect;
-
+            
             StopPublishing();
             StopMaintainingConnection();
 
@@ -288,7 +274,7 @@ namespace MQTTnet.Extensions.ManagedClient
             }
         }
 
-        public Task SubscribeAsync(IEnumerable<MqttTopicFilter> topicFilters)
+        public Task SubscribeAsync(ICollection<MqttTopicFilter> topicFilters)
         {
             ThrowIfDisposed();
 
@@ -316,7 +302,7 @@ namespace MQTTnet.Extensions.ManagedClient
             return CompletedTask.Instance;
         }
 
-        public Task UnsubscribeAsync(IEnumerable<string> topics)
+        public Task UnsubscribeAsync(ICollection<string> topics)
         {
             ThrowIfDisposed();
 
@@ -367,13 +353,6 @@ namespace MQTTnet.Extensions.ManagedClient
             return remainingTime < TimeSpan.Zero ? TimeSpan.Zero : remainingTime;
         }
 
-        CancellationTokenSource NewTimeoutToken(CancellationToken linkedToken)
-        {
-            var newTimeoutToken = CancellationTokenSource.CreateLinkedTokenSource(linkedToken);
-            newTimeoutToken.CancelAfter(Options.ClientOptions.Timeout);
-            return newTimeoutToken;
-        }
-
         async Task HandleSubscriptionExceptionAsync(Exception exception, List<MqttTopicFilter> addedSubscriptions, List<string> removedSubscriptions)
         {
             _logger.Warning(exception, "Synchronizing subscriptions failed.");
@@ -384,14 +363,6 @@ namespace MQTTnet.Extensions.ManagedClient
             }
         }
 
-        async Task HandleSubscriptionsResultAsync(SendSubscribeUnsubscribeResult subscribeUnsubscribeResult)
-        {
-            if (_subscriptionsChangedEvent.HasHandlers)
-            {
-                await _subscriptionsChangedEvent.InvokeAsync(new SubscriptionsChangedEventArgs(subscribeUnsubscribeResult.SubscribeResults, subscribeUnsubscribeResult.UnsubscribeResults)).ConfigureAwait(false);
-            }
-        }
-
         async Task MaintainConnectionAsync(CancellationToken cancellationToken)
         {
             try
@@ -416,7 +387,7 @@ namespace MQTTnet.Extensions.ManagedClient
                     {
                         if (_isCleanDisconnect)
                         {
-                            using (var disconnectTimeout = NewTimeoutToken(CancellationToken.None))
+                            using (var disconnectTimeout = new CancellationTokenSource(Options.ClientOptions.Timeout))
                             {
                                 await InternalClient.DisconnectAsync(new MqttClientDisconnectOptions(), disconnectTimeout.Token).ConfigureAwait(false);
                             }
@@ -466,7 +437,7 @@ namespace MQTTnet.Extensions.ManagedClient
 
                     cancellationToken.ThrowIfCancellationRequested();
 
-                    await TryPublishQueuedMessageAsync(message, cancellationToken).ConfigureAwait(false);
+                    await TryPublishQueuedMessageAsync(message).ConfigureAwait(false);
                 }
             }
             catch (OperationCanceledException)
@@ -482,7 +453,7 @@ namespace MQTTnet.Extensions.ManagedClient
             }
         }
 
-        async Task PublishReconnectSubscriptionsAsync(CancellationToken cancellationToken)
+        async Task PublishReconnectSubscriptionsAsync()
         {
             _logger.Info("Publishing subscriptions at reconnect");
 
@@ -493,7 +464,6 @@ namespace MQTTnet.Extensions.ManagedClient
                 if (_reconnectSubscriptions.Any())
                 {
                     topicFilters = new List<MqttTopicFilter>();
-                    SendSubscribeUnsubscribeResult subscribeUnsubscribeResult;
 
                     foreach (var sub in _reconnectSubscriptions)
                     {
@@ -501,14 +471,12 @@ namespace MQTTnet.Extensions.ManagedClient
 
                         if (topicFilters.Count == Options.MaxTopicFiltersInSubscribeUnsubscribePackets)
                         {
-                            subscribeUnsubscribeResult = await SendSubscribeUnsubscribe(topicFilters, null, cancellationToken).ConfigureAwait(false);
+                            await SendSubscribeUnsubscribe(topicFilters, null).ConfigureAwait(false);
                             topicFilters.Clear();
-                            await HandleSubscriptionsResultAsync(subscribeUnsubscribeResult).ConfigureAwait(false);
                         }
                     }
 
-                    subscribeUnsubscribeResult = await SendSubscribeUnsubscribe(topicFilters, null, cancellationToken).ConfigureAwait(false);
-                    await HandleSubscriptionsResultAsync(subscribeUnsubscribeResult).ConfigureAwait(false);
+                    await SendSubscribeUnsubscribe(topicFilters, null).ConfigureAwait(false);
                 }
             }
             catch (Exception exception)
@@ -524,7 +492,6 @@ namespace MQTTnet.Extensions.ManagedClient
             while (await _subscriptionsQueuedSignal.WaitAsync(GetRemainingTime(endTime), cancellationToken).ConfigureAwait(false))
             {
                 List<MqttTopicFilter> subscriptions;
-                SendSubscribeUnsubscribeResult subscribeUnsubscribeResult;
                 HashSet<string> unsubscriptions;
 
                 lock (_subscriptions)
@@ -560,14 +527,12 @@ namespace MQTTnet.Extensions.ManagedClient
 
                     if (addedTopicFilters.Count == Options.MaxTopicFiltersInSubscribeUnsubscribePackets)
                     {
-                        subscribeUnsubscribeResult = await SendSubscribeUnsubscribe(addedTopicFilters, null, cancellationToken).ConfigureAwait(false);
+                        await SendSubscribeUnsubscribe(addedTopicFilters, null).ConfigureAwait(false);
                         addedTopicFilters.Clear();
-                        await HandleSubscriptionsResultAsync(subscribeUnsubscribeResult).ConfigureAwait(false);
                     }
                 }
 
-                subscribeUnsubscribeResult = await SendSubscribeUnsubscribe(addedTopicFilters, null, cancellationToken).ConfigureAwait(false);
-                await HandleSubscriptionsResultAsync(subscribeUnsubscribeResult).ConfigureAwait(false);
+                await SendSubscribeUnsubscribe(addedTopicFilters, null).ConfigureAwait(false);
 
                 var removedTopicFilters = new List<string>();
                 foreach (var unSub in unsubscriptions)
@@ -576,14 +541,12 @@ namespace MQTTnet.Extensions.ManagedClient
 
                     if (removedTopicFilters.Count == Options.MaxTopicFiltersInSubscribeUnsubscribePackets)
                     {
-                        subscribeUnsubscribeResult = await SendSubscribeUnsubscribe(null, removedTopicFilters, cancellationToken).ConfigureAwait(false);
+                        await SendSubscribeUnsubscribe(null, removedTopicFilters).ConfigureAwait(false);
                         removedTopicFilters.Clear();
-                        await HandleSubscriptionsResultAsync(subscribeUnsubscribeResult).ConfigureAwait(false);
                     }
                 }
 
-                subscribeUnsubscribeResult = await SendSubscribeUnsubscribe(null, removedTopicFilters, cancellationToken).ConfigureAwait(false);
-                await HandleSubscriptionsResultAsync(subscribeUnsubscribeResult).ConfigureAwait(false);
+                await SendSubscribeUnsubscribe(null, removedTopicFilters).ConfigureAwait(false);
             }
         }
 
@@ -597,7 +560,7 @@ namespace MQTTnet.Extensions.ManagedClient
             MqttClientConnectResult connectResult = null;
             try
             {
-                using (var connectTimeout = NewTimeoutToken(cancellationToken))
+                using (var connectTimeout = new CancellationTokenSource(Options.ClientOptions.Timeout))
                 {
                     connectResult = await InternalClient.ConnectAsync(Options.ClientOptions, connectTimeout.Token).ConfigureAwait(false);
                 }
@@ -616,10 +579,8 @@ namespace MQTTnet.Extensions.ManagedClient
             }
         }
 
-        async Task<SendSubscribeUnsubscribeResult> SendSubscribeUnsubscribe(List<MqttTopicFilter> addedSubscriptions, List<string> removedSubscriptions, CancellationToken cancellationToken)
+        async Task SendSubscribeUnsubscribe(List<MqttTopicFilter> addedSubscriptions, List<string> removedSubscriptions)
         {
-            var subscribeResults = new List<MqttClientSubscribeResult>();
-            var unsubscribeResults = new List<MqttClientUnsubscribeResult>();
             try
             {
                 if (removedSubscriptions != null && removedSubscriptions.Any())
@@ -631,11 +592,7 @@ namespace MQTTnet.Extensions.ManagedClient
                         unsubscribeOptionsBuilder.WithTopicFilter(removedSubscription);
                     }
 
-                    using (var unsubscribeTimeout = NewTimeoutToken(cancellationToken))
-                    {
-                        var unsubscribeResult = await InternalClient.UnsubscribeAsync(unsubscribeOptionsBuilder.Build(), unsubscribeTimeout.Token).ConfigureAwait(false);
-                        unsubscribeResults.Add(unsubscribeResult);
-                    }
+                    await InternalClient.UnsubscribeAsync(unsubscribeOptionsBuilder.Build()).ConfigureAwait(false);
 
                     //clear because these worked, maybe the subscribe below will fail, only report those
                     removedSubscriptions.Clear();
@@ -650,19 +607,13 @@ namespace MQTTnet.Extensions.ManagedClient
                         subscribeOptionsBuilder.WithTopicFilter(addedSubscription);
                     }
 
-                    using (var subscribeTimeout = NewTimeoutToken(cancellationToken))
-                    {
-                        var subscribeResult = await InternalClient.SubscribeAsync(subscribeOptionsBuilder.Build(), subscribeTimeout.Token).ConfigureAwait(false);
-                        subscribeResults.Add(subscribeResult);
-                    }
+                    await InternalClient.SubscribeAsync(subscribeOptionsBuilder.Build()).ConfigureAwait(false);
                 }
             }
             catch (Exception exception)
             {
                 await HandleSubscriptionExceptionAsync(exception, addedSubscriptions, removedSubscriptions).ConfigureAwait(false);
             }
-
-            return new SendSubscribeUnsubscribeResult(subscribeResults, unsubscribeResults);
         }
 
         void StartPublishing()
@@ -708,7 +659,7 @@ namespace MQTTnet.Extensions.ManagedClient
             {
                 var oldConnectionState = InternalClient.IsConnected;
                 var connectionState = await ReconnectIfRequiredAsync(cancellationToken).ConfigureAwait(false);
-
+                
                 if (connectionState == ReconnectionResult.NotConnected)
                 {
                     StopPublishing();
@@ -716,7 +667,7 @@ namespace MQTTnet.Extensions.ManagedClient
                 }
                 else if (connectionState == ReconnectionResult.Reconnected)
                 {
-                    await PublishReconnectSubscriptionsAsync(cancellationToken).ConfigureAwait(false);
+                    await PublishReconnectSubscriptionsAsync().ConfigureAwait(false);
                     StartPublishing();
                 }
                 else if (connectionState == ReconnectionResult.Recovered)
@@ -746,26 +697,12 @@ namespace MQTTnet.Extensions.ManagedClient
             }
         }
 
-        async Task TryPublishQueuedMessageAsync(ManagedMqttApplicationMessage message, CancellationToken cancellationToken)
+        async Task TryPublishQueuedMessageAsync(ManagedMqttApplicationMessage message)
         {
             Exception transmitException = null;
-            bool acceptPublish = true;
             try
             {
-                if (_interceptingPublishMessageEvent.HasHandlers)
-                {
-                    var interceptEventArgs = new InterceptingPublishMessageEventArgs(message);
-                    await _interceptingPublishMessageEvent.InvokeAsync(interceptEventArgs).ConfigureAwait(false);
-                    acceptPublish = interceptEventArgs.AcceptPublish;
-                }
-
-                if (acceptPublish)
-                {
-                    using (var publishTimeout = NewTimeoutToken(cancellationToken))
-                    {
-                        await InternalClient.PublishAsync(message.ApplicationMessage, publishTimeout.Token).ConfigureAwait(false);
-                    }
-                }
+                await InternalClient.PublishAsync(message.ApplicationMessage).ConfigureAwait(false);
 
                 using (await _messageQueueLock.EnterAsync().ConfigureAwait(false)) //lock to avoid conflict with this.PublishAsync
                 {

Source/MQTTnet.Extensions.ManagedClient/SendSubscribeUnsubscribeResult.cs

@@ -1,23 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-using System.Collections.Generic;
-using MQTTnet.Client;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public sealed class SendSubscribeUnsubscribeResult
-    {
-        public SendSubscribeUnsubscribeResult(List<MqttClientSubscribeResult> subscribeResults, List<MqttClientUnsubscribeResult> unsubscribeResults)
-        {
-            SubscribeResults = subscribeResults ?? throw new ArgumentNullException(nameof(subscribeResults));
-            UnsubscribeResults = unsubscribeResults ?? throw new ArgumentNullException(nameof(unsubscribeResults));
-        }
-        
-        public List<MqttClientSubscribeResult> SubscribeResults { get; private set; }
-        
-        public List<MqttClientUnsubscribeResult> UnsubscribeResults { get; private set; }
-    }
-}

Source/MQTTnet.Extensions.ManagedClient/SubscriptionsChangedEventArgs.cs

@@ -1,23 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using MQTTnet.Client;
-using System;
-using System.Collections.Generic;
-
-namespace MQTTnet.Extensions.ManagedClient
-{
-    public sealed class SubscriptionsChangedEventArgs : EventArgs
-    {
-        public SubscriptionsChangedEventArgs(List<MqttClientSubscribeResult> subscribeResult, List<MqttClientUnsubscribeResult> unsubscribeResult)
-        {
-            SubscribeResult = subscribeResult ?? throw new ArgumentNullException(nameof(subscribeResult));
-            UnsubscribeResult = unsubscribeResult ?? throw new ArgumentNullException(nameof(unsubscribeResult));
-        }
-
-        public List<MqttClientSubscribeResult> SubscribeResult { get; }
-
-        public List<MqttClientUnsubscribeResult> UnsubscribeResult { get; }
-    }
-}

Source/MQTTnet.Extensions.Rpc/IMqttRpcClient.cs

@@ -1,9 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
 using System;
-using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using MQTTnet.Protocol;
@@ -12,8 +7,8 @@ namespace MQTTnet.Extensions.Rpc
 {
     public interface IMqttRpcClient : IDisposable
     {
-        Task<byte[]> ExecuteAsync(TimeSpan timeout, string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, IDictionary<string,object> parameters = null);
+        Task<byte[]> ExecuteAsync(TimeSpan timeout, string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel);
         
-        Task<byte[]> ExecuteAsync(string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, IDictionary<string, object> parameters = null, CancellationToken cancellationToken = default);
+        Task<byte[]> ExecuteAsync(string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, CancellationToken cancellationToken = default);
     }
 }

Source/MQTTnet.Extensions.Rpc/MqttRpcClient.cs

@@ -4,7 +4,6 @@
 
 using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -43,13 +42,13 @@ namespace MQTTnet.Extensions.Rpc
             _waitingCalls.Clear();
         }
 
-        public async Task<byte[]> ExecuteAsync(TimeSpan timeout, string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, IDictionary<string, object> parameters = null)
+        public async Task<byte[]> ExecuteAsync(TimeSpan timeout, string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
         {
             using (var timeoutToken = new CancellationTokenSource(timeout))
             {
                 try
                 {
-                    return await ExecuteAsync(methodName, payload, qualityOfServiceLevel, parameters, timeoutToken.Token).ConfigureAwait(false);
+                    return await ExecuteAsync(methodName, payload, qualityOfServiceLevel, timeoutToken.Token).ConfigureAwait(false);
                 }
                 catch (OperationCanceledException exception)
                 {
@@ -63,14 +62,19 @@ namespace MQTTnet.Extensions.Rpc
             }
         }
 
-        public async Task<byte[]> ExecuteAsync(string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, IDictionary<string, object> parameters = null, CancellationToken cancellationToken = default)
+        public async Task<byte[]> ExecuteAsync(string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, CancellationToken cancellationToken = default)
         {
             if (methodName == null)
             {
                 throw new ArgumentNullException(nameof(methodName));
             }
 
-            var context = new TopicGenerationContext(_mqttClient, _options, methodName, parameters, qualityOfServiceLevel);
+            if (!_mqttClient.IsConnected)
+            {
+                throw new MqttClientDisconnectedException(null);
+            }
+
+            var context = new TopicGenerationContext(_mqttClient, _options, methodName, qualityOfServiceLevel);
             var topicNames = _options.TopicGenerationStrategy.CreateRpcTopics(context);
 
             var requestTopic = topicNames.RequestTopic;

Source/MQTTnet.Extensions.Rpc/MqttRpcClientExtensions.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Collections.Generic;
 using System.Text;
 using System.Threading.Tasks;
 using MQTTnet.Protocol;
@@ -12,13 +11,13 @@ namespace MQTTnet.Extensions.Rpc
 {
     public static class MqttRpcClientExtensions
     {
-        public static Task<byte[]> ExecuteAsync(this IMqttRpcClient client, TimeSpan timeout, string methodName, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel, IDictionary<string,object> parameters = null)
+        public static Task<byte[]> ExecuteAsync(this IMqttRpcClient client, TimeSpan timeout, string methodName, string payload, MqttQualityOfServiceLevel qualityOfServiceLevel)
         {
             if (client == null) throw new ArgumentNullException(nameof(client));
 
             var buffer = Encoding.UTF8.GetBytes(payload ?? string.Empty);
 
-            return client.ExecuteAsync(timeout, methodName, buffer, qualityOfServiceLevel, parameters);
+            return client.ExecuteAsync(timeout, methodName, buffer, qualityOfServiceLevel);
         }
     }
 }

Source/MQTTnet.Extensions.Rpc/Options/TopicGeneration/TopicGenerationContext.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Collections.Generic;
 using MQTTnet.Client;
 using MQTTnet.Protocol;
 
@@ -11,11 +10,9 @@ namespace MQTTnet.Extensions.Rpc
 {
     public sealed class TopicGenerationContext
     {
-        public TopicGenerationContext(IMqttClient mqttClient, MqttRpcClientOptions options, string methodName,
-            IDictionary<string, object> parameters, MqttQualityOfServiceLevel qualityOfServiceLevel)
+        public TopicGenerationContext(IMqttClient mqttClient, MqttRpcClientOptions options, string methodName, MqttQualityOfServiceLevel qualityOfServiceLevel)
         {
             MethodName = methodName ?? throw new ArgumentNullException(nameof(methodName));
-            Parameters = parameters;
             QualityOfServiceLevel = qualityOfServiceLevel;
             MqttClient = mqttClient ?? throw new ArgumentNullException(nameof(mqttClient));
             Options = options ?? throw new ArgumentNullException(nameof(options));
@@ -23,8 +20,6 @@ namespace MQTTnet.Extensions.Rpc
 
         public string MethodName { get; }
 
-        public IDictionary<string, object> Parameters { get; }
-
         public IMqttClient MqttClient { get; }
 
         public MqttRpcClientOptions Options { get; }

Source/MQTTnet.Extensions.TopicTemplate/MQTTnet.Extensions.TopicTemplate.csproj

@@ -1,73 +0,0 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
-    <PropertyGroup>
-        <TargetFrameworks>netstandard1.3;netstandard2.0;netstandard2.1;netcoreapp3.1;net5.0;net6.0;net7.0</TargetFrameworks>
-        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net461;net48</TargetFrameworks>
-        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' AND '$(MSBuildRuntimeType)' != 'Core' ">$(TargetFrameworks);uap10.0</TargetFrameworks>
-        
-        <AssemblyName>MQTTnet.Extensions.TopicTemplate</AssemblyName>
-        <RootNamespace>MQTTnet.Extensions.TopicTemplate</RootNamespace>
-        <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
-        <Company>The contributors of MQTTnet</Company>
-        <Product>MQTTnet</Product>
-        <Description>
-           Provides mqtt topic templating logic to support dispatch,
-           routing and similar functionality based on the well known moustache syntax (AsyncAPI compatible).
-        </Description>
-		<PackageReadmeFile>README.md</PackageReadmeFile>
-        <Authors>The contributors of MQTTnet</Authors>
-        <PackageId>MQTTnet.Extensions.TopicTemplate</PackageId>
-        <SignAssembly>false</SignAssembly>
-        <DelaySign>false</DelaySign>
-        <PublishRepositoryUrl>true</PublishRepositoryUrl>
-        <IncludeSymbols>true</IncludeSymbols>
-        <SymbolPackageFormat>snupkg</SymbolPackageFormat>
-        <Copyright>Copyright (c) .NET Foundation and Contributors</Copyright>
-        <PackageProjectUrl>https://github.com/dotnet/MQTTnet</PackageProjectUrl>
-        <RepositoryUrl>https://github.com/dotnet/MQTTnet.git</RepositoryUrl>
-        <RepositoryType>git</RepositoryType>
-        <PackageTags>MQTT Message Queue Telemetry MQTTClient Messaging Routing AsyncAPI Template</PackageTags>
-        <NeutralLanguage>en-US</NeutralLanguage>
-        <PackageIcon>nuget.png</PackageIcon>
-        <EmbedUntrackedSources>true</EmbedUntrackedSources>
-        <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
-        <PackageLicenseExpression>MIT</PackageLicenseExpression>
-        <PackageReleaseNotes>For release notes please go to MQTTnet release notes (https://www.nuget.org/packages/MQTTnet/).</PackageReleaseNotes>
-        <GenerateDocumentationFile>true</GenerateDocumentationFile>
-        <NoWarn>1591;NETSDK1138</NoWarn>
-    </PropertyGroup>
-
-    <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0'">
-        <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>
-        <NugetTargetMoniker>UAP,Version=v10.0</NugetTargetMoniker>
-        <TargetPlatformIdentifier>UAP</TargetPlatformIdentifier>
-        <TargetPlatformVersion>10.0.18362.0</TargetPlatformVersion>
-        <TargetPlatformMinVersion>10.0.10240.0</TargetPlatformMinVersion>
-        <TargetFrameworkIdentifier>.NETCore</TargetFrameworkIdentifier>
-        <TargetFrameworkVersion>v5.0</TargetFrameworkVersion>
-        <DefineConstants>$(DefineConstants);WINDOWS_UWP</DefineConstants>
-        <DefaultLanguage>en</DefaultLanguage>
-        <LanguageTargets>$(MSBuildExtensionsPath)\Microsoft\WindowsXaml\v$(VisualStudioVersion)\Microsoft.Windows.UI.Xaml.CSharp.targets</LanguageTargets>
-    </PropertyGroup>
-
-    <ItemGroup>
-        <None Include="README.md">
-            <Pack>True</Pack>
-            <PackagePath>\</PackagePath>
-        </None>
-        <None Include="..\..\Images\nuget.png">
-            <Pack>True</Pack>
-            <PackagePath>\</PackagePath>
-        </None>
-    </ItemGroup>
-    
-    <ItemGroup>
-        <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
-        <PackageReference Include="System.ValueTuple" Version="4.5.0" />
-    </ItemGroup>
-
-    <ItemGroup>
-        <ProjectReference Include="..\MQTTnet\MQTTnet.csproj" />
-    </ItemGroup>
-
-</Project>

Source/MQTTnet.Extensions.TopicTemplate/MqttTopicTemplate.cs

@@ -1,357 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text.RegularExpressions;
-using System.Threading;
-using MQTTnet.Protocol;
-
-namespace MQTTnet.Extensions.TopicTemplate
-{
-    /// <summary>
-    ///     A topic template is an MQTT topic filter string that may contain
-    ///     segments in curly braces called parameters. This well-known
-    ///     'moustache' syntax also matches AsyncAPI Channel Address Expressions.
-    ///     The topic template is designed to support dynamic subscription/publication,
-    ///     message-topic matching and routing. It is intended to be more safe and
-    ///     convenient than String.Format() for aforementioned purposes.
-    /// </summary>
-    /// <example>
-    ///     topic/subtopic/{parameter}/{otherParameter}
-    /// </example>
-    public sealed class MqttTopicTemplate : IEquatable<MqttTopicTemplate>
-    {
-        static readonly Regex MoustacheRegex = new Regex("{([^/]+?)}", RegexOptions.Compiled);
-        
-        readonly string[] _parameterSegments;
-        
-        string _topicFilter;
-        
-        /// <summary>
-        ///     Create a topic template from an mqtt topic filter with moustache placeholders.
-        /// </summary>
-        /// <param
-        ///     name="topicTemplate">
-        /// </param>
-        /// <exception
-        ///     cref="ArgumentNullException">
-        /// </exception>
-        public MqttTopicTemplate(string topicTemplate)
-        {
-            if (topicTemplate == null)
-            {
-                throw new ArgumentNullException(nameof(topicTemplate));
-            }
-            
-            MqttTopicValidator.ThrowIfInvalidSubscribe(topicTemplate);
-            
-            Template = topicTemplate;
-            _parameterSegments = topicTemplate.Split(MqttTopicFilterComparer.LevelSeparator)
-                .Select(segment => MoustacheRegex.Match(segment).Groups[1].Value)
-                .Select(s => s.Length > 0 ? s : null)
-                .ToArray();
-        }
-        
-        /// <summary>
-        ///     Yield the template parameter names.
-        /// </summary>
-        public IEnumerable<string> Parameters => _parameterSegments.Where(s => s != null);
-        
-        /// <summary>
-        ///     The topic template string representation, e.g. A/B/{foo}/D.
-        /// </summary>
-        public string Template { get; }
-        
-        /// <summary>
-        ///     The topic template as an MQTT topic filter (+ substituted for all parameters). If the template
-        ///     ends with a multi-level wildcard (hash), this will be reflected here.
-        /// </summary>
-        public string TopicFilter
-        {
-            get
-            {
-                LazyInitializer.EnsureInitialized(ref _topicFilter, () => MoustacheRegex.Replace(Template, MqttTopicFilterComparer.SingleLevelWildcard.ToString()));
-                return _topicFilter;
-            }
-        }
-        
-        /// <summary>
-        ///     Return the topic filter of this template, ending with a multi-level wildcard (hash).
-        /// </summary>
-        public string TopicTreeRootFilter
-        {
-            get
-            {
-                var filter = TopicFilter;
-                // append slash if neccessary
-                if (filter.Length > 0 && !filter.EndsWith(MqttTopicFilterComparer.LevelSeparator.ToString()) &&
-                    !filter.EndsWith(MqttTopicFilterComparer.MultiLevelWildcard.ToString()))
-                {
-                    filter += MqttTopicFilterComparer.LevelSeparator;
-                }
-                
-                // append hash if neccessary
-                if (!filter.EndsWith(MqttTopicFilterComparer.MultiLevelWildcard.ToString()))
-                {
-                    filter += MqttTopicFilterComparer.MultiLevelWildcard;
-                }
-                
-                return filter;
-            }
-        }
-        
-        public bool Equals(MqttTopicTemplate other)
-        {
-            return other != null && Template == other.Template;
-        }
-        
-        public override bool Equals(object obj)
-        {
-            if (ReferenceEquals(null, obj))
-            {
-                return false;
-            }
-            
-            if (ReferenceEquals(this, obj))
-            {
-                return true;
-            }
-            
-            if (obj.GetType() != GetType())
-            {
-                return false;
-            }
-            
-            return Equals((MqttTopicTemplate)obj);
-        }
-        
-        /// <summary>
-        ///     Determine the shortest common prefix of the given templates. Partial segments
-        ///     are not returned.
-        /// </summary>
-        /// <param
-        ///     name="templates">
-        ///     topic templates
-        /// </param>
-        /// <returns></returns>
-        public static MqttTopicTemplate FindCanonicalPrefix(IEnumerable<MqttTopicTemplate> templates)
-        {
-            string root = null;
-            
-            string CommonPrefix(string a, string b)
-            {
-                var maxIndex = Math.Min(a.Length, b.Length) - 1;
-                for (var i = 0; i <= maxIndex; i++)
-                {
-                    if (a[i] != b[i])
-                    {
-                        return a.Substring(0, i);
-                    }
-                }
-                
-                return a.Substring(0, maxIndex+1);
-            }
-            
-            foreach (string topic in from template in templates select template.Template)
-            {
-                root = root == null ? topic : CommonPrefix(root, topic);
-            }
-            
-            if (string.IsNullOrEmpty(root))
-                return new MqttTopicTemplate(MqttTopicFilterComparer.MultiLevelWildcard.ToString());
-            
-            if (root.Contains(MqttTopicFilterComparer.LevelSeparator) &&
-                !root.EndsWith(MqttTopicFilterComparer.LevelSeparator.ToString()) &&
-                !root.EndsWith("}"))
-            {
-                root = root.Substring(0, root.LastIndexOf(MqttTopicFilterComparer.LevelSeparator)+1);
-            }
-            
-            if (root.EndsWith(MqttTopicFilterComparer.LevelSeparator.ToString()))
-                root += MqttTopicFilterComparer.SingleLevelWildcard;
-
-            return new MqttTopicTemplate(root);
-        }
-        
-        public override int GetHashCode()
-        {
-            return Template.GetHashCode();
-        }
-        
-        /// <summary>
-        ///     Test if this topic template matches a given topic.
-        /// </summary>
-        /// <param
-        ///     name="topic">
-        ///     a fully specified topic
-        /// </param>
-        /// <param
-        ///     name="subtree">
-        ///     true to match including the subtree (multi-level wildcard)
-        /// </param>
-        /// <returns>true iff the topic matches the template's filter</returns>
-        /// <exception
-        ///     cref="InvalidOperationException">
-        /// </exception>
-        /// <exception
-        ///     cref="ArgumentException">
-        ///     if the topic is invalid
-        /// </exception>
-        public bool MatchesTopic(string topic, bool subtree = false)
-        {
-            var comparison = MqttTopicFilterComparer.Compare(topic, subtree ? TopicTreeRootFilter : TopicFilter);
-            if (comparison == MqttTopicFilterCompareResult.FilterInvalid)
-            {
-                throw new InvalidOperationException("Invalid filter");
-            }
-            
-            if (comparison == MqttTopicFilterCompareResult.TopicInvalid)
-            {
-                throw new ArgumentException("Invalid topic", nameof(topic));
-            }
-            
-            return comparison == MqttTopicFilterCompareResult.IsMatch;
-        }
-        
-        /// <summary>
-        ///     Extract the parameter values from a topic corresponding to the template
-        ///     parameters. The topic has to match this template.
-        /// </summary>
-        /// <param
-        ///     name="topic">
-        ///     the topic
-        /// </param>
-        /// <returns>an enumeration of (parameter, index, value)</returns>
-        public IEnumerable<(string parameter, int index, string value)> ParseParameterValues(string topic)
-        {
-            if (!MatchesTopic(topic))
-            {
-                throw new ArgumentException("the topic has to match this template", nameof(topic));
-            }
-            
-            return parseParameterValuesInternal(topic);
-        }
-        
-        /// <summary>
-        ///     Extract the parameter values from the message topic corresponding to the template
-        ///     parameters. The message topic has to match this topic template.
-        /// </summary>
-        /// <param
-        ///     name="message">
-        ///     the message
-        /// </param>
-        /// <returns>an enumeration of (parameter, index, value)</returns>
-        public IEnumerable<(string parameter, int index, string value)> ParseParameterValues(MqttApplicationMessage message)
-        {
-            return ParseParameterValues(message.Topic);
-        }
-        
-        /// <summary>
-        ///     Try to set a parameter to a given value. If the parameter is not present,
-        ///     this is returned. The value must not contain slashes.
-        /// </summary>
-        /// <param
-        ///     name="parameter">
-        ///     a template parameter
-        /// </param>
-        /// <param
-        ///     name="value">
-        ///     a string
-        /// </param>
-        /// <returns></returns>
-        public MqttTopicTemplate TrySetParameter(string parameter, string value)
-        {
-            if (parameter != null && _parameterSegments.Contains(parameter))
-            {
-                return WithParameter(parameter, value);
-            }
-            
-            return this;
-        }
-        
-        /// <summary>
-        ///     Replace the given parameter with a single-level wildcard (plus sign).
-        /// </summary>
-        /// <param
-        ///     name="parameter">
-        ///     parameter name
-        /// </param>
-        /// <returns>the topic template (without the parameter)</returns>
-        public MqttTopicTemplate WithoutParameter(string parameter)
-        {
-            if (string.IsNullOrEmpty(parameter) || !_parameterSegments.Contains(parameter))
-            {
-                throw new ArgumentException("topic template parameter must exist.");
-            }
-            
-            return ReplaceInternal(parameter, MqttTopicFilterComparer.SingleLevelWildcard.ToString());
-        }
-        
-        /// <summary>
-        ///     Substitute a parameter with a given value, thus removing the parameter. If the parameter is not present,
-        ///     the method trows. The value must not contain slashes or wildcards.
-        /// </summary>
-        /// <param
-        ///     name="parameter">
-        ///     a template parameter
-        /// </param>
-        /// <param
-        ///     name="value">
-        ///     a string
-        /// </param>
-        /// <exception
-        ///     cref="ArgumentException">
-        ///     when the parameter is not present
-        /// </exception>
-        /// <returns>the topic template (without the parameter)</returns>
-        public MqttTopicTemplate WithParameter(string parameter, string value)
-        {
-            if (value == null || string.IsNullOrEmpty(parameter) || !_parameterSegments.Contains(parameter) ||
-                value.Contains(MqttTopicFilterComparer.LevelSeparator) ||
-                value.Contains(MqttTopicFilterComparer.SingleLevelWildcard) ||
-                value.Contains(MqttTopicFilterComparer.MultiLevelWildcard))
-            {
-                throw new ArgumentException("parameter must exist and value must not contain slashes or wildcard.");
-            }
-            
-            return ReplaceInternal(parameter, value);
-        }
-        
-        private MqttTopicTemplate ReplaceInternal(string parameter, string value)
-        {
-            var moustache = "{" + parameter + "}";
-            return new MqttTopicTemplate(Template.Replace(moustache, value));
-        }
-        
-        /// <summary>
-        ///     Reuse parameters as they are extracted using another topic template on this template
-        ///     when the parameter name matches. Useful
-        ///     for compatibility routing.
-        /// </summary>
-        /// <param
-        ///     name="parameters">
-        /// </param>
-        /// <returns></returns>
-        public MqttTopicTemplate WithParameterValuesFrom(IEnumerable<(string parameter, int index, string value)> parameters)
-        {
-            return parameters.Aggregate(this, (t, p) => t.TrySetParameter(p.parameter, p.value));
-        }
-        
-        IEnumerable<(string parameter, int index, string value)> parseParameterValuesInternal(string topic)
-        {
-            // because we have a match, we know the segment array is at least the template's length
-            var segments = topic.Split(MqttTopicFilterComparer.LevelSeparator);
-            for (var i = 0; i < _parameterSegments.Length; i++)
-            {
-                var name = _parameterSegments[i];
-                if (name != null)
-                {
-                    yield return (name, i, segments[i]);
-                }
-            }
-        }
-    }
-}

Source/MQTTnet.Extensions.TopicTemplate/README.md

@@ -1,79 +0,0 @@
-# MQTTNet.Extensions.TopicTemplate
-
-Provides mqtt topic templating logic to support dispatch, routing and
-similar functionality based on the well known moustache syntax, aka
-AsyncAPI dynamic channel address.
-
-Generating and parsing MQTT topics and topic filters is often done in
-an ad-hoc fashion, leading to error-prone code and subtly introduced
-showstoppers like forgetting to strip a slash from a parameter.  To
-remedy, this extension aids you write safe, maintainable logic
-for topic generation, routing and dispatch.
-
-
-## How it works
-
-The package lets you write MQTTNet code like:
-```csharp
-var template = new MqttTopicTemplate("App/v1/{sender}/message");
-
-var filter = new MqttTopicFilterBuilder()
-    .WithTopicTemplate(template) // (1)
-    .WithAtLeastOnceQoS()
-    .WithNoLocal()
-    .Build();
-
-// filter.Topic == "App/v1/+/message"
-
-var myTopic = template
-    .WithParameter("sender", "me, myself & i"); // (2)
-
-var message = new MqttApplicationMessageBuilder()
-    .WithTopicTemplate(  // (3)
-        myTopic)
-    .WithPayload("Hello!")
-    .Build();
-
-// message.Topic == "App/v1/me, myself & i/message"
-
-Assert.IsTrue(message.MatchesTopicTemplate(template)); // (4)
-```
-
-At (1), the parameter "sender" was automatically replaced by a plus sign
-(single level wildcard) because the caller is creating a topic filter.
-
-Using the same template (they are immutable), you can send
-a message. At (2), we replace the parameter with a known value.
-If that value contained a level separator or topic filter only
-characters, we'd get an ArgumentException. If we forgot to replace
-the parameter "sender" (e.g. when placing template not myTopic),
-we would be prevented from sending at (3).
-
-On the receiving side, a message can be matched to a template
-using code like at (4).
-
-These daily tasks become much safer and easier to code than 
-string.Format() and Split() allow for. More elaborate computation is supported
-too. You could extract the sender using the template or route
-messages based on topic content.
-
-## Features
-
-- Safe handling of topic parameters in moustache syntax
-- Simplifies topic generation and parsing logic
-- Match topics and extract the values of their parameters
-- Translate between topic templates to ease dynamic routing
-- Derive a canonical topic filter from a bunch of templates
-- Integrates with MQTTNet message, subscription and filter builders
-- Extension method friendly (sealed class with one public ctor)
-
-## Additional documentation
-
-- Some of the [unit tests](https://github.com/dotnet/MQTTnet/blob/master/Source/MQTTnet.Tests/Extensions/MqttTopicTemplate_Tests.cs) are instructive
-- Some examples feature the extension, e.g. TopicGenerator, Client_Subscribe_Samples
-
-## Feedback
-
-Report any issues with the main project on https://github.com/dotnet/MQTTnet/issues
-
-

Source/MQTTnet.Extensions.TopicTemplate/TopicTemplateExtensions.cs

@@ -1,190 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-using System.Linq;
-using MQTTnet.Client;
-using MQTTnet.Packets;
-using MQTTnet.Protocol;
-
-namespace MQTTnet.Extensions.TopicTemplate
-{
-    public static class TopicTemplateExtensions
-    {
-        /// <summary>
-        ///     Modify this message builder to respond to a given message. The
-        ///     message's response topic and correlation data are included
-        ///     in the message builder.
-        /// </summary>
-        /// <param
-        ///     name="builder">
-        ///     a message builder
-        /// </param>
-        /// <param
-        ///     name="message">
-        ///     a message with a response topic
-        /// </param>
-        /// <returns>a message builder</returns>
-        /// <see
-        ///     cref="BuildResponse" />
-        public static MqttApplicationMessageBuilder AsResponseTo(this MqttApplicationMessageBuilder builder, MqttApplicationMessage message)
-        {
-            if (!string.IsNullOrEmpty(message.ResponseTopic))
-            {
-                throw new ArgumentException("message does not have a response topic");
-            }
-
-            return builder.WithTopic(message.ResponseTopic).WithCorrelationData(message.CorrelationData);
-        }
-
-        /// <summary>
-        ///     Set the filter topic according to the template, with
-        ///     remaining template parameters substituted by single-level
-        ///     wildcard.
-        /// </summary>
-        /// <param
-        ///     name="topicTemplate">
-        ///     a topic template
-        /// </param>
-        /// <param
-        ///     name="subscribeTreeRoot">
-        ///     whether to subscribe to the whole topic tree
-        /// </param>
-        /// <returns>the modified topic filter</returns>
-        public static MqttTopicFilterBuilder BuildFilter(this MqttTopicTemplate topicTemplate, bool subscribeTreeRoot = false)
-        {
-            return new MqttTopicFilterBuilder().WithTopicTemplate(topicTemplate, subscribeTreeRoot);
-        }
-
-        /// <summary>
-        ///     Create a message builder from this template. The template must not have
-        ///     remaining parameters. 
-        /// </summary>
-        /// <param
-        ///     name="topicTemplate">
-        ///     a parameterless topic template
-        /// </param>
-        /// <returns>a new message builder</returns>
-        /// <exception
-        ///     cref="ArgumentException">
-        ///     if the topic template has parameters
-        /// </exception>
-        public static MqttApplicationMessageBuilder BuildMessage(this MqttTopicTemplate topicTemplate)
-        {
-            return new MqttApplicationMessageBuilder().WithTopicTemplate(topicTemplate);
-        }
-        
-        /// <summary>
-        ///     Return a message builder to respond to this message. The
-        ///     message's response topic and correlation data are included
-        ///     in the response message builder.
-        /// </summary>
-        /// <param
-        ///     name="message">
-        ///     a message with a response topic
-        /// </param>
-        /// <returns>a message builder</returns>
-        /// <see
-        ///     cref="AsResponseTo" />
-        public static MqttApplicationMessageBuilder BuildResponse(this MqttApplicationMessage message)
-        {
-            return new MqttApplicationMessageBuilder().AsResponseTo(message);
-        }
-
-        /// <summary>
-        ///     Return whether the message matches the given topic template.
-        /// </summary>
-        /// <param
-        ///     name="message">
-        ///     a message
-        /// </param>
-        /// <param
-        ///     name="topicTemplate">
-        ///     a topic template
-        /// </param>
-        /// <param
-        ///     name="subtree">
-        ///     whether to include the topic subtree
-        /// </param>
-        /// <returns></returns>
-        public static bool MatchesTopicTemplate(this MqttApplicationMessage message, MqttTopicTemplate topicTemplate, bool subtree = false)
-        {
-            return topicTemplate.MatchesTopic(message.Topic, subtree);
-        }
-
-        /// <summary>
-        ///     Set the filter topic according to the template, with
-        ///     template parameters substituted by a single-level
-        ///     wildcard.
-        /// </summary>
-        /// <param
-        ///     name="builder">
-        ///     a filter builder
-        /// </param>
-        /// <param
-        ///     name="topicTemplate">
-        ///     a topic template
-        /// </param>
-        /// <param
-        ///     name="subscribeTreeRoot">
-        ///     whether to subscribe to the whole topic tree
-        /// </param>
-        /// <returns>the modified topic filter</returns>
-        public static MqttTopicFilterBuilder WithTopicTemplate(this MqttTopicFilterBuilder builder, MqttTopicTemplate topicTemplate, bool subscribeTreeRoot = false)
-        {
-            return builder.WithTopic(subscribeTreeRoot ? topicTemplate.TopicTreeRootFilter : topicTemplate.TopicFilter);
-        }
-
-        /// <summary>
-        /// Set the subscription to the template's topic filter.
-        /// </summary>
-        /// <returns>the builder</returns>
-        public static MqttClientSubscribeOptionsBuilder WithTopicTemplate(
-            this MqttClientSubscribeOptionsBuilder builder,
-            MqttTopicTemplate topicTemplate,
-            MqttQualityOfServiceLevel qualityOfServiceLevel = MqttQualityOfServiceLevel.AtMostOnce,
-            bool noLocal = false,
-            bool retainAsPublished = false,
-            MqttRetainHandling retainHandling = MqttRetainHandling.SendAtSubscribe)
-        {
-            return builder.WithTopicFilter(
-                new MqttTopicFilter
-                {
-                    Topic = topicTemplate.TopicFilter,
-                    QualityOfServiceLevel = qualityOfServiceLevel,
-                    NoLocal = noLocal,
-                    RetainAsPublished = retainAsPublished,
-                    RetainHandling = retainHandling
-                });
-        }
-        
-        /// <summary>
-        ///     Set the publication topic according to the topic template. The template
-        ///     must not have remaining (unset) parameters or contain wildcards.
-        /// </summary>
-        /// <param
-        ///     name="builder">
-        ///     a message builder
-        /// </param>
-        /// <param
-        ///     name="topicTemplate">
-        ///     a parameterless topic template
-        /// </param>
-        /// <returns>the modified message builder</returns>
-        /// <exception
-        ///     cref="ArgumentException">
-        ///     if the topic template has parameters
-        /// </exception>
-        public static MqttApplicationMessageBuilder WithTopicTemplate(this MqttApplicationMessageBuilder builder, MqttTopicTemplate topicTemplate)
-        {
-            if (topicTemplate.Parameters.Any())
-            {
-                throw new ArgumentException("topic templates must be parameter-less when sending " + topicTemplate.Template);
-            }
-
-            MqttTopicValidator.ThrowIfInvalid(topicTemplate.Template);
-            return builder.WithTopic(topicTemplate.Template);
-        }
-    }
-}

Source/MQTTnet.Extensions.WebSocket4Net/WebSocket4NetMqttChannel.cs

@@ -47,13 +47,13 @@ namespace MQTTnet.Extensions.WebSocket4Net
             var uri = _webSocketOptions.Uri;
             if (!uri.StartsWith("ws://", StringComparison.OrdinalIgnoreCase) && !uri.StartsWith("wss://", StringComparison.OrdinalIgnoreCase))
             {
-                if (_webSocketOptions.TlsOptions?.UseTls == true)
+                if (_webSocketOptions.TlsOptions?.UseTls == false)
                 {
-                    uri = "wss://" + uri;
+                    uri = "ws://" + uri;
                 }
                 else
                 {
-                    uri = "ws://" + uri;
+                    uri = "wss://" + uri;
                 }
             }
             
@@ -76,7 +76,7 @@ namespace MQTTnet.Extensions.WebSocket4Net
             List<KeyValuePair<string, string>> customHeaders = null;
             if (_webSocketOptions.RequestHeaders != null)
             {
-                customHeaders = _webSocketOptions.RequestHeaders.ToList();
+                customHeaders = _webSocketOptions.RequestHeaders.Select(i => new KeyValuePair<string, string>(i.Key, i.Value)).ToList();
             }
 
             EndPoint proxy = null;
@@ -92,7 +92,18 @@ namespace MQTTnet.Extensions.WebSocket4Net
             var webSocketVersion = WebSocketVersion.None;
             var receiveBufferSize = 0;
 
-            var certificates = _webSocketOptions.TlsOptions?.ClientCertificatesProvider?.GetCertificates();
+            var certificates = new X509CertificateCollection();
+            if (_webSocketOptions.TlsOptions?.Certificates != null)
+            {
+                foreach (var certificate in _webSocketOptions.TlsOptions.Certificates)
+                {
+#if WINDOWS_UWP
+                    certificates.Add(new X509Certificate(certificate));
+#else
+                    certificates.Add(certificate);
+#endif
+                }
+            }
 
             _webSocket = new WebSocket(uri, subProtocol, cookies, customHeaders, userAgent, origin, webSocketVersion, proxy, sslProtocols, receiveBufferSize)
             {

Source/MQTTnet.TestApp/ClientTest.cs

@@ -4,7 +4,6 @@
 
 using MQTTnet.Client;
 using System;
-using System.Net;
 using System.Text;
 using System.Threading.Tasks;
 using MQTTnet.Diagnostics;
@@ -28,7 +27,7 @@ namespace MQTTnet.TestApp
                 {
                     ChannelOptions = new MqttClientTcpOptions
                     {
-                        RemoteEndpoint = new DnsEndPoint("127.0.0.1", 0)
+                        Server = "127.0.0.1"
                     }
                 };
 

Source/MQTTnet.TestApp/MQTTnet.TestApp.csproj

@@ -10,7 +10,6 @@
         <EnforceCodeStyleInBuild>false</EnforceCodeStyleInBuild>
         <DisableImplicitAspNetCoreAnalyzers>true</DisableImplicitAspNetCoreAnalyzers>
         <NoWarn>1591;NETSDK1138</NoWarn>
-        <LangVersion>7.3</LangVersion>
     </PropertyGroup>
 
     <ItemGroup>
@@ -21,7 +20,6 @@
         <ProjectReference Include="..\..\Source\MQTTnet.Extensions.ManagedClient\MQTTnet.Extensions.ManagedClient.csproj" />
         <ProjectReference Include="..\..\Source\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj" />
         <ProjectReference Include="..\..\Source\MQTTnet\MQTTnet.csproj" />
-        <ProjectReference Include="..\MQTTnet.Extensions.TopicTemplate\MQTTnet.Extensions.TopicTemplate.csproj" />
     </ItemGroup>
 
 </Project>

Source/MQTTnet.TestApp/ManagedClientTest.cs

@@ -7,7 +7,6 @@ using System.Threading.Tasks;
 using System.IO;
 using Newtonsoft.Json;
 using System.Collections.Generic;
-using System.Net;
 using MQTTnet.Client;
 using MQTTnet.Extensions.ManagedClient;
 using MQTTnet.Internal;
@@ -29,7 +28,7 @@ namespace MQTTnet.TestApp
                     Credentials = new RandomPassword(),
                     ChannelOptions = new MqttClientTcpOptions
                     {
-                        RemoteEndpoint = new DnsEndPoint("broker.hivemq.com", 0)
+                        Server = "broker.hivemq.com"
                     }
                 },
 

Source/MQTTnet.TestApp/PerformanceTest.cs

@@ -5,13 +5,13 @@
 using System;
 using System.Diagnostics;
 using System.Linq;
-using System.Net;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using MQTTnet.Client;
 using MQTTnet.Protocol;
 using MQTTnet.Server;
+using MqttClient = MQTTnet.Client.MqttClient;
 
 namespace MQTTnet.TestApp
 {
@@ -25,7 +25,7 @@ namespace MQTTnet.TestApp
                 {
                     ChannelOptions = new MqttClientTcpOptions
                     {
-                        RemoteEndpoint = new DnsEndPoint("127.0.0.1", 0)
+                        Server = "127.0.0.1"
                     },
                     CleanSession = true
                 };
@@ -71,7 +71,7 @@ namespace MQTTnet.TestApp
                 {
                     ChannelOptions = new MqttClientTcpOptions
                     {
-                        RemoteEndpoint = new DnsEndPoint("127.0.0.1", 0)
+                        Server = "127.0.0.1"
                     }
                 };
 
@@ -114,10 +114,7 @@ namespace MQTTnet.TestApp
             {
                 var options = new MqttClientOptions
                 {
-                    ChannelOptions = new MqttClientTcpOptions
-                    {
-                        RemoteEndpoint = new DnsEndPoint("localhost", 0)
-                    },
+                    ChannelOptions = new MqttClientTcpOptions { Server = "localhost" },
                     ClientId = "Client1",
                     CleanSession = true
                 };
@@ -221,7 +218,7 @@ namespace MQTTnet.TestApp
                 {
                     ChannelOptions = new MqttClientTcpOptions
                     {
-                        RemoteEndpoint = new DnsEndPoint("127.0.0.1", 0)
+                        Server = "127.0.0.1"
                     },
                     CleanSession = true
                 };
@@ -272,7 +269,7 @@ namespace MQTTnet.TestApp
                 {
                     ChannelOptions = new MqttClientTcpOptions
                     {
-                        RemoteEndpoint = new DnsEndPoint("127.0.0.1", 0)
+                        Server = "127.0.0.1"
                     },
                     CleanSession = true
                 };
@@ -323,7 +320,7 @@ namespace MQTTnet.TestApp
                 {
                     ChannelOptions = new MqttClientTcpOptions
                     {
-                        RemoteEndpoint = new DnsEndPoint("127.0.0.1", 0)
+                        Server = "127.0.0.1"
                     },
                     CleanSession = true
                 };

Source/MQTTnet.TestApp/PublicBrokerTest.cs

@@ -20,155 +20,143 @@ namespace MQTTnet.TestApp
         {
 #if NET5_0_OR_GREATER
             // TLS13 is only available in Net5.0
-            var unsafeTls13 = new MqttClientTlsOptions
+            var unsafeTls13 = new MqttClientOptionsBuilderTlsParameters
             {
                 UseTls = true,
                 SslProtocol = SslProtocols.Tls13,
                 // Don't use this in production code. This handler simply allows any invalid certificate to work.
-                AllowUntrustedCertificates = true,
-                IgnoreCertificateChainErrors = true,
-                CertificateValidationHandler = _ => true
+                CertificateValidationHandler = w => true
             };
 #endif
             // Also defining TLS12 for servers that don't seem no to support TLS13.
-            var unsafeTls12 = new MqttClientTlsOptions
+            var unsafeTls12 = new MqttClientOptionsBuilderTlsParameters
             {
                 UseTls = true,
                 SslProtocol = SslProtocols.Tls12,
                 // Don't use this in production code. This handler simply allows any invalid certificate to work.
-                AllowUntrustedCertificates = true,
-                IgnoreCertificateChainErrors = true,
-                CertificateValidationHandler = _ => true
+                CertificateValidationHandler = w => true
             };
 
             // mqtt.eclipseprojects.io
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "mqtt.eclipseprojects.io TCP",
                 new MqttClientOptionsBuilder().WithTcpServer("mqtt.eclipseprojects.io", 1883).WithProtocolVersion(MqttProtocolVersion.V311).Build());
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "mqtt.eclipseprojects.io WS",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("mqtt.eclipseprojects.io:80/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build());
+                new MqttClientOptionsBuilder().WithWebSocketServer("mqtt.eclipseprojects.io:80/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build());
 
 #if NET5_0_OR_GREATER
-            await ExecuteTestsAsync("mqtt.eclipseprojects.io WS TLS13",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("mqtt.eclipseprojects.io:443/mqtt"))
-                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls13).Build());
+            await ExecuteTestAsync("mqtt.eclipseprojects.io WS TLS13",
+                new MqttClientOptionsBuilder().WithWebSocketServer("mqtt.eclipseprojects.io:443/mqtt")
+                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls13).Build());
             
-            await ExecuteTestsAsync("mqtt.eclipseprojects.io WS TLS13 (WebSocket4Net)",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("mqtt.eclipseprojects.io:443/mqtt"))
-                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls13).Build(),
+            await ExecuteTestAsync("mqtt.eclipseprojects.io WS TLS13 (WebSocket4Net)",
+                new MqttClientOptionsBuilder().WithWebSocketServer("mqtt.eclipseprojects.io:443/mqtt")
+                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls13).Build(),
                     true);
 #endif
 
             // test.mosquitto.org
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "test.mosquitto.org TCP",
                 new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 1883).WithProtocolVersion(MqttProtocolVersion.V311).Build());
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "test.mosquitto.org TCP - Authenticated",
                 new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 1884).WithCredentials("rw", "readwrite").WithProtocolVersion(MqttProtocolVersion.V311).Build());
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "test.mosquitto.org TCP TLS12",
-                new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8883).WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls12).Build());
+                new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8883).WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls12).Build());
 
 #if NET5_0_OR_GREATER
-            await ExecuteTestsAsync("test.mosquitto.org TCP TLS13",
+            await ExecuteTestAsync("test.mosquitto.org TCP TLS13",
                 new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8883)
-                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls13).Build());
+                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls13).Build());
 #endif
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "test.mosquitto.org TCP TLS12 - Authenticated",
                 new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8885)
                     .WithCredentials("rw", "readwrite")
                     .WithProtocolVersion(MqttProtocolVersion.V311)
-                    .WithTlsOptions(unsafeTls12)
+                    .WithTls(unsafeTls12)
                     .Build());
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "test.mosquitto.org WS",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("test.mosquitto.org:8080/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build());
+                new MqttClientOptionsBuilder().WithWebSocketServer("test.mosquitto.org:8080/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build());
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "test.mosquitto.org WS (WebSocket4Net)",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("test.mosquitto.org:8080/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build(),
+                new MqttClientOptionsBuilder().WithWebSocketServer("test.mosquitto.org:8080/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build(),
                 true);
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "test.mosquitto.org WS TLS12",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("test.mosquitto.org:8081/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls12).Build());
+                new MqttClientOptionsBuilder().WithWebSocketServer("test.mosquitto.org:8081/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls12).Build());
 
-            await ExecuteTestsAsync(
-                "test.mosquitto.org WS TLS12 (WebSocket4Net)",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("test.mosquitto.org:8081/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls12).Build(),
-                true);
+            // await ExecuteTestAsync(
+            //     "test.mosquitto.org WS TLS12 (WebSocket4Net)",
+            //     new MqttClientOptionsBuilder().WithWebSocketServer("test.mosquitto.org:8081/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls12).Build(),
+            //     true);
 
             // broker.emqx.io
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "broker.emqx.io TCP",
                 new MqttClientOptionsBuilder().WithTcpServer("broker.emqx.io", 1883).WithProtocolVersion(MqttProtocolVersion.V311).Build());
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "broker.emqx.io TCP TLS12",
-                new MqttClientOptionsBuilder().WithTcpServer("broker.emqx.io", 8883).WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls12).Build());
+                new MqttClientOptionsBuilder().WithTcpServer("broker.emqx.io", 8883).WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls12).Build());
 
 #if NET5_0_OR_GREATER
-            await ExecuteTestsAsync("broker.emqx.io TCP TLS13",
+            await ExecuteTestAsync("broker.emqx.io TCP TLS13",
                 new MqttClientOptionsBuilder().WithTcpServer("broker.emqx.io", 8883)
-                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls13).Build());
+                    .WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls13).Build());
 #endif
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "broker.emqx.io WS",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.emqx.io:8083/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build());
+                new MqttClientOptionsBuilder().WithWebSocketServer("broker.emqx.io:8083/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build());
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "broker.emqx.io WS (WebSocket4Net)",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.emqx.io:8084/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build(),
+                new MqttClientOptionsBuilder().WithWebSocketServer("broker.emqx.io:8084/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build(),
                 true);
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "broker.emqx.io WS TLS12",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.emqx.io:8084/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls12).Build());
+                new MqttClientOptionsBuilder().WithWebSocketServer("broker.emqx.io:8084/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls12).Build());
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "broker.emqx.io WS TLS12 (WebSocket4Net)",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.emqx.io:8084/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).WithTlsOptions(unsafeTls12).Build(),
+                new MqttClientOptionsBuilder().WithWebSocketServer("broker.emqx.io:8084/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).WithTls(unsafeTls12).Build(),
                 true);
 
             // broker.hivemq.com
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "broker.hivemq.com TCP",
                 new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com", 1883).WithProtocolVersion(MqttProtocolVersion.V311).Build());
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "broker.hivemq.com WS",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.hivemq.com:8000/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build());
+                new MqttClientOptionsBuilder().WithWebSocketServer("broker.hivemq.com:8000/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build());
 
-            await ExecuteTestsAsync(
+            await ExecuteTestAsync(
                 "broker.hivemq.com WS (WebSocket4Net)",
-                new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.hivemq.com:8000/mqtt")).WithProtocolVersion(MqttProtocolVersion.V311).Build(),
+                new MqttClientOptionsBuilder().WithWebSocketServer("broker.hivemq.com:8000/mqtt").WithProtocolVersion(MqttProtocolVersion.V311).Build(),
                 true);
 
             // mqtt.swifitch.cz: Does not seem to operate any more
+
             // cloudmqtt.com: Cannot test because it does not offer a free plan any more.
 
             Write("Finished.", ConsoleColor.White);
             Console.ReadLine();
         }
 
-        static async Task ExecuteTestsAsync(string name, MqttClientOptions options, bool useWebSocket4Net = false)
-        {
-            options.ProtocolVersion = MqttProtocolVersion.V311;
-            await ExecuteTestAsync(name + " V3.1.1", options, useWebSocket4Net);
-
-            options.ProtocolVersion = MqttProtocolVersion.V500;
-            await ExecuteTestAsync(name + " V5.0.0", options, useWebSocket4Net);
-        }
-        
         static async Task ExecuteTestAsync(string name, MqttClientOptions options, bool useWebSocket4Net = false)
         {
             try
@@ -209,10 +197,9 @@ namespace MQTTnet.TestApp
 
                 Write("[OK]\n", ConsoleColor.Green);
             }
-            catch (Exception exception)
+            catch (Exception e)
             {
-                Write("[FAILED]" + Environment.NewLine, ConsoleColor.Red);
-                Write(exception + Environment.NewLine, ConsoleColor.Red);
+                Write("[FAILED] " + e.Message + "\n", ConsoleColor.Red);
             }
         }
 

Source/MQTTnet.TestApp/TopicGenerator.cs

@@ -1,6 +1,6 @@
 using System;
 using System.Collections.Generic;
-using MQTTnet.Extensions.TopicTemplate;
+using System.Text;
 
 namespace MQTTnet.TestApp
 {
@@ -17,8 +17,6 @@ namespace MQTTnet.TestApp
             singleWildcardTopicsByPublisher = new Dictionary<string, List<string>>();
             multiWildcardTopicsByPublisher = new Dictionary<string, List<string>>();
 
-            MqttTopicTemplate baseTemplate = new MqttTopicTemplate("{publisher}/{building}/{level}/{sensor}");
-
             // Find some reasonable distribution across three topic levels
             var topicsPerLevel = (int)Math.Pow(numTopicsPerPublisher, (1.0 / 3.0));
 
@@ -42,37 +40,25 @@ namespace MQTTnet.TestApp
                 int publisherTopicCount = 0;
 
                 var publisherName = "pub" + p;
-                var publisherTemplate = baseTemplate
-                    .WithParameter("publisher", publisherName);
                 for (var l1 = 0; l1 < numLevel1Topics; ++l1)
                 {
-                    var l1Template = publisherTemplate
-                        .WithParameter("building", "building" + (l1 + 1));
                     for (var l2 = 0; l2 < numLevel2Topics; ++l2)
                     {
-                        var l2Template = l1Template
-                            .WithParameter("level", "level" + (l2 + 1));
                         for (var l3 = 0; l3 < maxNumLevel3Topics; ++l3)
                         {
                             if (publisherTopicCount >= numTopicsPerPublisher)
                                 break;
 
-                            var topic = l2Template
-                                .WithParameter("sensor", "sensor" + (l3 + 1))
-                                .TopicFilter;
+                            var topic = string.Format("{0}/building{1}/level{2}/sensor{3}", publisherName, l1 + 1, l2 + 1, l3 + 1);
                             AddPublisherTopic(publisherName, topic, topicsByPublisher);
 
                             if (l2 == 0)
                             {
-                                var singleWildcardTopic = l1Template
-                                        .WithParameter("sensor", "sensor" + (l3 + 1))
-                                        .TopicFilter;
+                                var singleWildcardTopic = string.Format("{0}/building{1}/+/sensor{2}", publisherName, l1 + 1, l3 + 1);
                                 AddPublisherTopic(publisherName, singleWildcardTopic, singleWildcardTopicsByPublisher);
                                 if (l1 == 0)
                                 {
-                                    var multiWildcardTopic = publisherTemplate
-                                        .WithParameter("sensor", "sensor" + (l3 + 1))
-                                        .TopicFilter;
+                                    var multiWildcardTopic = string.Format("{0}/+/level{1}/+", publisherName, l3 + 1);
                                     AddPublisherTopic(publisherName, multiWildcardTopic, multiWildcardTopicsByPublisher);
                                 }
                             }

Source/MQTTnet.Tests/Clients/LowLevelMqttClient/LowLevelMqttClient_Tests.cs

@@ -13,7 +13,6 @@ using MQTTnet.Exceptions;
 using MQTTnet.LowLevelClient;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
-using MQTTnet.Server;
 
 namespace MQTTnet.Tests.Clients.LowLevelMqttClient
 {

Source/MQTTnet.Tests/Clients/ManagedMqttClient/ManagedMqttClient_Tests.cs

@@ -13,7 +13,6 @@ using MQTTnet.Diagnostics;
 using MQTTnet.Extensions.ManagedClient;
 using MQTTnet.Formatter;
 using MQTTnet.Internal;
-using MQTTnet.Packets;
 using MQTTnet.Protocol;
 using MQTTnet.Server;
 using MQTTnet.Tests.Mockups;
@@ -23,6 +22,99 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
     [TestClass]
     public sealed class ManagedMqttClient_Tests : BaseTestClass
     {
+        [TestMethod]
+        public async Task Expose_Custom_Connection_Error()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                var server = await testEnvironment.StartServer();
+                
+                server.ValidatingConnectionAsync += args =>
+                {
+                    args.ReasonCode = MqttConnectReasonCode.BadUserNameOrPassword;
+                    return CompletedTask.Instance;
+                };
+
+                var managedClient = testEnvironment.Factory.CreateManagedMqttClient();
+
+                MqttClientDisconnectedEventArgs disconnectedArgs = null;
+                managedClient.DisconnectedAsync += args =>
+                {
+                    disconnectedArgs = args;
+                    return CompletedTask.Instance;
+                };
+                
+                var clientOptions = testEnvironment.Factory.CreateManagedMqttClientOptionsBuilder().WithClientOptions(testEnvironment.CreateDefaultClientOptions()).Build();
+                await managedClient.StartAsync(clientOptions);
+
+                await LongTestDelay();
+
+                Assert.IsNotNull(disconnectedArgs);
+                Assert.AreEqual(MqttClientConnectResultCode.BadUserNameOrPassword, disconnectedArgs.ConnectResult.ResultCode);
+            }
+        }
+        
+        [TestMethod]
+        public async Task Receive_While_Not_Cleanly_Disconnected()
+        {
+            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
+            {
+                await testEnvironment.StartServer(o => o.WithPersistentSessions());
+
+                var senderClient = await testEnvironment.ConnectClient();
+
+                // Prepare managed client.
+                var managedClient = testEnvironment.Factory.CreateManagedMqttClient();
+                await managedClient.SubscribeAsync("#");
+                var receivedMessages = testEnvironment.CreateApplicationMessageHandler(managedClient);
+                
+                var managedClientOptions = new ManagedMqttClientOptions
+                {
+                    ClientOptions = testEnvironment.Factory.CreateClientOptionsBuilder()
+                        .WithTcpServer("127.0.0.1", testEnvironment.ServerPort)
+                        .WithClientId(nameof(Receive_While_Not_Cleanly_Disconnected) + "_managed")
+                        .WithCleanSession(false)
+                        .Build()
+                };
+
+                await managedClient.StartAsync(managedClientOptions);
+                await LongTestDelay();
+                await LongTestDelay();
+                
+                // Send test data.
+                await senderClient.PublishStringAsync("topic1");
+                await LongTestDelay();
+                await LongTestDelay();
+                
+                receivedMessages.AssertReceivedCountEquals(1);
+
+                // Stop the managed client but keep session at server (not clean disconnect required).
+                await managedClient.StopAsync(false);
+                await LongTestDelay();
+                
+                // Send new messages in the meantime.
+                await senderClient.PublishStringAsync("topic2", qualityOfServiceLevel: MqttQualityOfServiceLevel.ExactlyOnce);
+                await LongTestDelay();
+                
+                // Start the managed client, it should receive the new message.
+                await managedClient.StartAsync(managedClientOptions);
+                await LongTestDelay();
+                
+                receivedMessages.AssertReceivedCountEquals(2);
+                
+                // Stop and start again, no new message should be received.
+                for (var i = 0; i < 3; i++)
+                {
+                    await managedClient.StopAsync(false);
+                    await LongTestDelay();
+                    await managedClient.StartAsync(managedClientOptions);
+                    await LongTestDelay();
+                }
+
+                receivedMessages.AssertReceivedCountEquals(2);
+            }
+        }
+
         [TestMethod]
         public async Task Connect_To_Invalid_Server()
         {
@@ -89,38 +181,6 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
             }
         }
 
-        [TestMethod]
-        public async Task Expose_Custom_Connection_Error()
-        {
-            using (var testEnvironment = CreateTestEnvironment())
-            {
-                var server = await testEnvironment.StartServer();
-
-                server.ValidatingConnectionAsync += args =>
-                {
-                    args.ReasonCode = MqttConnectReasonCode.BadUserNameOrPassword;
-                    return CompletedTask.Instance;
-                };
-
-                var managedClient = testEnvironment.Factory.CreateManagedMqttClient();
-
-                MqttClientDisconnectedEventArgs disconnectedArgs = null;
-                managedClient.DisconnectedAsync += args =>
-                {
-                    disconnectedArgs = args;
-                    return CompletedTask.Instance;
-                };
-
-                var clientOptions = testEnvironment.Factory.CreateManagedMqttClientOptionsBuilder().WithClientOptions(testEnvironment.CreateDefaultClientOptions()).Build();
-                await managedClient.StartAsync(clientOptions);
-
-                await LongTestDelay();
-
-                Assert.IsNotNull(disconnectedArgs);
-                Assert.AreEqual(MqttClientConnectResultCode.BadUserNameOrPassword, disconnectedArgs.ConnectResult.ResultCode);
-            }
-        }
-
         [TestMethod]
         public async Task ManagedClients_Will_Message_Send()
         {
@@ -164,67 +224,6 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
             }
         }
 
-        [TestMethod]
-        public async Task Receive_While_Not_Cleanly_Disconnected()
-        {
-            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
-            {
-                await testEnvironment.StartServer(o => o.WithPersistentSessions());
-
-                var senderClient = await testEnvironment.ConnectClient();
-
-                // Prepare managed client.
-                var managedClient = testEnvironment.Factory.CreateManagedMqttClient();
-                await managedClient.SubscribeAsync("#");
-                var receivedMessages = testEnvironment.CreateApplicationMessageHandler(managedClient);
-
-                var managedClientOptions = new ManagedMqttClientOptions
-                {
-                    ClientOptions = testEnvironment.Factory.CreateClientOptionsBuilder()
-                        .WithTcpServer("127.0.0.1", testEnvironment.ServerPort)
-                        .WithClientId(nameof(Receive_While_Not_Cleanly_Disconnected) + "_managed")
-                        .WithCleanSession(false)
-                        .Build()
-                };
-
-                await managedClient.StartAsync(managedClientOptions);
-                await LongTestDelay();
-                await LongTestDelay();
-
-                // Send test data.
-                await senderClient.PublishStringAsync("topic1");
-                await LongTestDelay();
-                await LongTestDelay();
-
-                receivedMessages.AssertReceivedCountEquals(1);
-
-                // Stop the managed client but keep session at server (not clean disconnect required).
-                await managedClient.StopAsync(false);
-                await LongTestDelay();
-
-                // Send new messages in the meantime.
-                await senderClient.PublishStringAsync("topic2", qualityOfServiceLevel: MqttQualityOfServiceLevel.ExactlyOnce);
-                await LongTestDelay();
-
-                // Start the managed client, it should receive the new message.
-                await managedClient.StartAsync(managedClientOptions);
-                await LongTestDelay();
-
-                receivedMessages.AssertReceivedCountEquals(2);
-
-                // Stop and start again, no new message should be received.
-                for (var i = 0; i < 3; i++)
-                {
-                    await managedClient.StopAsync(false);
-                    await LongTestDelay();
-                    await managedClient.StartAsync(managedClientOptions);
-                    await LongTestDelay();
-                }
-
-                receivedMessages.AssertReceivedCountEquals(2);
-            }
-        }
-
         [TestMethod]
         public async Task Start_Stop()
         {
@@ -376,7 +375,7 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
                 var clientOptions = new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1", testEnvironment.ServerPort);
 
                 var receivedManagedMessages = new List<MqttApplicationMessage>();
-
+                
                 var managedClient = testEnvironment.Factory.CreateManagedMqttClient(testEnvironment.CreateClient());
                 managedClient.ApplicationMessageReceivedAsync += e =>
                 {
@@ -404,7 +403,7 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
                 // Make sure that it gets received after subscribing again.
                 await managedClient.SubscribeAsync("topic");
                 await LongTestDelay();
-
+                
                 Assert.AreEqual(2, receivedManagedMessages.Count);
             }
         }
@@ -422,7 +421,7 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
                 var receivingClient = await CreateManagedClientAsync(testEnvironment, null, connectionCheckInterval);
                 var sendingClient = await testEnvironment.ConnectClient();
 
-                await sendingClient.PublishAsync(new MqttApplicationMessage { Topic = "topic", PayloadSegment = new ArraySegment<byte>(new byte[] { 1 }), Retain = true });
+                await sendingClient.PublishAsync(new MqttApplicationMessage { Topic = "topic", Payload = new byte[] { 1 }, Retain = true });
 
                 var subscribeTime = DateTime.UtcNow;
 
@@ -438,109 +437,6 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
             }
         }
 
-
-        [TestMethod]
-        public async Task ManagedClients_CanInterceptPublishedMessage_PreventingPublish()
-        {
-            using (var testEnvironment = CreateTestEnvironment())
-            {
-                await testEnvironment.StartServer();
-
-                var receivedMessagesCount = 0;
-                var interceptedMessagesCount = 0;
-
-                var clientOptions = new MqttClientOptionsBuilder()
-                    .WithTcpServer("127.0.0.1", testEnvironment.ServerPort)
-                    .Build();
-
-                var sendingClient = testEnvironment.CreateClient();
-                var sendingManagedClient = new MQTTnet.Extensions.ManagedClient.ManagedMqttClient(sendingClient, testEnvironment.ClientLogger);
-
-                await sendingManagedClient.StartAsync(new ManagedMqttClientOptionsBuilder().WithClientOptions(clientOptions).Build());
-
-                // Wait until the managed client is fully set up and running.
-                await Task.Delay(1000);
-
-                var receivingClient = await testEnvironment.ConnectClient();
-
-                receivingClient.ApplicationMessageReceivedAsync += e =>
-                {
-                    Interlocked.Increment(ref receivedMessagesCount);
-                    return CompletedTask.Instance;
-                };
-                sendingManagedClient.InterceptPublishMessageAsync += e =>
-                {
-                    Interlocked.Increment(ref interceptedMessagesCount);
-                    e.AcceptPublish = false;
-                    return CompletedTask.Instance;
-                };
-
-                await receivingClient.SubscribeAsync("My/last/will");
-
-                // Wait for arrival of the will message at the receiver.
-                await Task.Delay(5000);
-
-                await sendingManagedClient.EnqueueAsync("My/last/will", "hello world");
-
-                // Wait for arrival of the will message at the receiver.
-                await Task.Delay(5000);
-
-                Assert.AreEqual(0, receivedMessagesCount);
-                Assert.AreEqual(1, interceptedMessagesCount);
-            }
-        }
-
-        [TestMethod]
-        public async Task ManagedClients_CanInterceptPublishedMessage_AllowingPublish()
-        {
-            using (var testEnvironment = CreateTestEnvironment())
-            {
-                await testEnvironment.StartServer();
-
-                var receivedMessagesCount = 0;
-                var interceptedMessagesCount = 0;
-
-                var clientOptions = new MqttClientOptionsBuilder()
-                    .WithTcpServer("127.0.0.1", testEnvironment.ServerPort)
-                    .Build();
-
-                var sendingClient = testEnvironment.CreateClient();
-                var sendingManagedClient = new MQTTnet.Extensions.ManagedClient.ManagedMqttClient(sendingClient, testEnvironment.ClientLogger);
-
-                await sendingManagedClient.StartAsync(new ManagedMqttClientOptionsBuilder().WithClientOptions(clientOptions).Build());
-
-                // Wait until the managed client is fully set up and running.
-                await Task.Delay(1000);
-
-                var receivingClient = await testEnvironment.ConnectClient();
-
-                receivingClient.ApplicationMessageReceivedAsync += e =>
-                {
-                    Interlocked.Increment(ref receivedMessagesCount);
-                    return CompletedTask.Instance;
-                };
-                sendingManagedClient.InterceptPublishMessageAsync += e =>
-                {
-                    Interlocked.Increment(ref interceptedMessagesCount);
-                    e.AcceptPublish = true;
-                    return CompletedTask.Instance;
-                };
-
-                await receivingClient.SubscribeAsync("My/last/will");
-
-                // Wait for arrival of the will message at the receiver.
-                await Task.Delay(5000);
-
-                await sendingManagedClient.EnqueueAsync("My/last/will", "hello world");
-
-                // Wait for arrival of the will message at the receiver.
-                await Task.Delay(5000);
-
-                Assert.AreEqual(1, receivedMessagesCount);
-                Assert.AreEqual(1, interceptedMessagesCount);
-            }
-        }
-
         // This case also serves as a regression test for the previous behavior which re-published
         // each and every existing subscriptions with every new subscription that was made
         // (causing performance problems and having the visible symptom of retained messages being received again)
@@ -558,7 +454,7 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
                 //wait a bit for the subscription to become established
                 await Task.Delay(500);
 
-                await sendingClient.PublishAsync(new MqttApplicationMessage { Topic = "topic", PayloadSegment = new ArraySegment<byte>(new byte[] { 1 }), Retain = true });
+                await sendingClient.PublishAsync(new MqttApplicationMessage { Topic = "topic", Payload = new byte[] { 1 }, Retain = true });
 
                 var messages = await SetupReceivingOfMessages(managedClient, 1);
 
@@ -575,154 +471,16 @@ namespace MQTTnet.Tests.Clients.ManagedMqttClient
             }
         }
 
-        [TestMethod]
-        public async Task Subscribe_Does_Not_Hang_On_Server_Stop()
-        {
-            var timeout = TimeSpan.FromSeconds(2);
-            var testTimeout = TimeSpan.FromSeconds(timeout.TotalSeconds * 2);
-            const string topic = "test_topic_2";
-            using (var testEnvironment = CreateTestEnvironment())
-            using (var managedClient = await CreateManagedClientAsync(testEnvironment, timeout: timeout))
-            {
-                testEnvironment.IgnoreClientLogErrors = true;
-                bool reject = true;
-                var receivedOnServer = new SemaphoreSlim(0, 1);
-                var failedOnClient = new SemaphoreSlim(0, 1);
-                testEnvironment.Server.InterceptingInboundPacketAsync += e =>
-                {
-                    if (e.Packet is MqttSubscribePacket)
-                    {
-                        if (reject)
-                        {
-                            e.ProcessPacket = false;
-                        }
-                        receivedOnServer.Release();
-                    }
-
-                    return CompletedTask.Instance;
-                };
-                managedClient.SynchronizingSubscriptionsFailedAsync += e =>
-                {
-                    failedOnClient.Release();
-                    return CompletedTask.Instance;
-                };
-
-                await managedClient.SubscribeAsync(topic);
-                Assert.IsTrue(await receivedOnServer.WaitAsync(testTimeout));
-                Assert.IsTrue(await failedOnClient.WaitAsync(testTimeout));
-
-                reject = false;
-                await managedClient.SubscribeAsync(topic);
-                Assert.IsTrue(await receivedOnServer.WaitAsync(testTimeout));
-            }
-        }
-
-        [TestMethod]
-        public async Task Unsubscribe_Does_Not_Hang_On_Server_Stop()
-        {
-            var timeout = TimeSpan.FromSeconds(2);
-            var testTimeout = TimeSpan.FromSeconds(timeout.TotalSeconds * 2);
-            const string topic = "test_topic_2";
-            using (var testEnvironment = CreateTestEnvironment())
-            using (var managedClient = await CreateManagedClientAsync(testEnvironment, timeout: timeout))
-            {
-                testEnvironment.IgnoreClientLogErrors = true;
-                bool reject = true;
-                var receivedOnServer = new SemaphoreSlim(0, 1);
-                var failedOnClient = new SemaphoreSlim(0, 1);
-                testEnvironment.Server.InterceptingInboundPacketAsync += e =>
-                {
-                    if (e.Packet is MqttUnsubscribePacket)
-                    {
-                        if (reject)
-                        {
-                            e.ProcessPacket = false;
-                        }
-                        receivedOnServer.Release();
-                    }
-                    else if (e.Packet is MqttSubscribePacket)
-                    {
-                        receivedOnServer.Release();
-                    }
-
-                    return CompletedTask.Instance;
-                };
-                managedClient.SynchronizingSubscriptionsFailedAsync += e =>
-                {
-                    failedOnClient.Release();
-                    return CompletedTask.Instance;
-                };
-
-                await managedClient.SubscribeAsync(topic);
-                Assert.IsTrue(await receivedOnServer.WaitAsync(testTimeout));
-
-                await managedClient.UnsubscribeAsync(topic);
-                Assert.IsTrue(await receivedOnServer.WaitAsync(testTimeout));
-                Assert.IsTrue(await failedOnClient.WaitAsync(testTimeout));
-
-                reject = false;
-                await managedClient.UnsubscribeAsync(topic);
-                Assert.IsTrue(await receivedOnServer.WaitAsync(testTimeout));
-            }
-        }
-
-        [TestMethod]
-        public async Task Publish_Does_Not_Hang_On_Server_Error()
-        {
-            var timeout = TimeSpan.FromSeconds(2);
-            var testTimeout = TimeSpan.FromSeconds(timeout.TotalSeconds * 2);
-
-            const string topic = "test_topic_42";
-
-            using (var testEnvironment = CreateTestEnvironment())
-            using (var managedClient = await CreateManagedClientAsync(testEnvironment, timeout: timeout))
-            {
-                testEnvironment.IgnoreClientLogErrors = true;
-                bool reject = true;
-                var receivedOnServer = new TaskCompletionSource<object>();
-                managedClient.ApplicationMessageProcessedAsync += e => Task.FromResult(reject &= e.Exception is null);
-                testEnvironment.Server.InterceptingInboundPacketAsync += e =>
-                {
-                    if (e.Packet is MqttPublishPacket)
-                    {
-                        if (reject)
-                        {
-                            e.ProcessPacket = false;
-                        }
-                        else
-                        {
-                            receivedOnServer.TrySetResult(null);
-                        }
-                    }
-
-                    return CompletedTask.Instance;
-                };
-
-                await managedClient.EnqueueAsync(new MqttApplicationMessage { Topic = topic, PayloadSegment = new ArraySegment<byte>(new byte[] { 1 }), Retain = true, QualityOfServiceLevel = MqttQualityOfServiceLevel.AtLeastOnce });
-
-                var timeoutTask = Task.Delay(testTimeout);
-
-                var firstDone = await Task.WhenAny(receivedOnServer.Task, timeoutTask);
-                Assert.AreEqual(receivedOnServer.Task, firstDone, "Client is hung on publish!");
-            }
-        }
-
         async Task<MQTTnet.Extensions.ManagedClient.ManagedMqttClient> CreateManagedClientAsync(
             TestEnvironment testEnvironment,
             IMqttClient underlyingClient = null,
             TimeSpan? connectionCheckInterval = null,
-            string host = "localhost",
-            TimeSpan? timeout = null)
+            string host = "localhost")
         {
             await testEnvironment.StartServer();
 
             var clientOptions = new MqttClientOptionsBuilder().WithTcpServer(host, testEnvironment.ServerPort);
 
-            if (timeout != null)
-            {
-                clientOptions.WithTimeout(timeout.Value);
-            }
-
             var managedOptions = new ManagedMqttClientOptionsBuilder().WithClientOptions(clientOptions).Build();
 
             // Use a short connection check interval so that subscription operations are performed quickly

Source/MQTTnet.Tests/Clients/MqttClient/MqttClient_Connection_Tests.cs

@@ -4,12 +4,12 @@
 
 using System;
 using System.Collections.Generic;
-using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Client;
 using MQTTnet.Exceptions;
+using MQTTnet.Extensions.Rpc;
 using MQTTnet.Formatter;
 using MQTTnet.Internal;
 using MQTTnet.Packets;
@@ -21,6 +21,38 @@ namespace MQTTnet.Tests.Clients.MqttClient
     [TestClass]
     public sealed class MqttClient_Connection_Tests : BaseTestClass
     {
+        [TestMethod]
+        public async Task Connect_Disconnect_Connect()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                await testEnvironment.StartServer();
+
+                var clientOptions = testEnvironment.CreateDefaultClientOptions();
+                var client = testEnvironment.CreateClient();
+
+                await client.ConnectAsync(clientOptions);
+                await client.DisconnectAsync();
+                await client.ConnectAsync(clientOptions);
+            }
+        }
+
+        [TestMethod]
+        [ExpectedException(typeof(InvalidOperationException))]
+        public async Task Connect_Multiple_Times_Should_Fail()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                await testEnvironment.StartServer();
+
+                var clientOptions = testEnvironment.CreateDefaultClientOptions();
+                var client = testEnvironment.CreateClient();
+
+                await client.ConnectAsync(clientOptions);
+                await client.ConnectAsync(clientOptions);
+            }
+        }
+
         [TestMethod]
         [ExpectedException(typeof(MqttCommunicationException))]
         public async Task Connect_To_Invalid_Server_Port_Not_Opened()
@@ -66,7 +98,7 @@ namespace MQTTnet.Tests.Clients.MqttClient
                         return CompletedTask.Instance;
                     };
 
-                    await client.ConnectAsync(new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1").Build());
+                    await client.ConnectAsync(new MqttClientOptionsBuilder().WithTcpServer("1.2.3.4").Build());
 
                     Assert.Fail("Must fail!");
                 }
@@ -168,123 +200,6 @@ namespace MQTTnet.Tests.Clients.MqttClient
             }
         }
 
-        class TestClientKerberosAuthenticationHandler : IMqttExtendedAuthenticationExchangeHandler
-        {
-            public static IReadOnlyList<string> ServerTokens { get; } = new List<string>()
-            {
-                string.Empty,
-                "reply context token"
-            };
-
-            public static IReadOnlyList<string> ClientTokens { get; } = new List<string>()
-            {
-                string.Empty,
-                "initial context token",
-                string.Empty
-            };
-
-            int tokenCursor;
-
-            public async Task HandleRequestAsync(MqttExtendedAuthenticationExchangeContext context)
-            {
-                if (context.AuthenticationMethod != "GS2-KRB5")
-                {
-                    throw new InvalidOperationException("Wrong authentication method");
-                }
-
-                Assert.IsTrue(tokenCursor < ServerTokens.Count, "No more server tokens were expected.");
-                var expectedToken = ServerTokens[tokenCursor++];
-                Assert.AreEqual(expectedToken, Encoding.UTF8.GetString(context.AuthenticationData));
-
-                var sendOptions = new MqttExtendedAuthenticationExchangeData
-                {
-                    AuthenticationData = Encoding.UTF8.GetBytes(ClientTokens[tokenCursor])
-                };
-
-                await context.Client.SendExtendedAuthenticationExchangeDataAsync(sendOptions, context.CancellationToken);
-            }
-        }
-
-        [TestMethod]
-        public async Task Use_Extended_Authentication()
-        {
-            // Use Kerberos sample from the MQTT RFC.
-            var kerberosAuthenticationHandler = new TestClientKerberosAuthenticationHandler();
-
-            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
-            {
-                var server = await testEnvironment.StartServer();
-
-                server.ValidatingConnectionAsync += async args =>
-                {
-                    if (args.AuthenticationMethod == "GS2-KRB5")
-                    {
-                        var authenticationData = args.AuthenticationData;
-                        string expectedToken;
-                        int tokenCursor;
-                        for (tokenCursor = 0; tokenCursor < TestClientKerberosAuthenticationHandler.ServerTokens.Count; tokenCursor++)
-                        {
-                            expectedToken = TestClientKerberosAuthenticationHandler.ClientTokens[tokenCursor];
-                            Assert.AreEqual(expectedToken, Encoding.UTF8.GetString(authenticationData), "The received client token is not correct.");
-
-                            var serverToken = TestClientKerberosAuthenticationHandler.ServerTokens[tokenCursor];
-                            var authOptions = testEnvironment.Factory.CreateMqttExtendedAuthenticationExchangeOptionsBuilder().WithAuthenticationData(serverToken).Build();
-                            var result = await args.SendExtendedAuthenticationExchangeDataAsync(authOptions);
-
-                            authenticationData = result.AuthenticationData;
-                        }
-
-                        expectedToken = TestClientKerberosAuthenticationHandler.ClientTokens[tokenCursor];
-                        Assert.AreEqual(expectedToken, Encoding.UTF8.GetString(authenticationData), "The received client token is not correct.");
-                        args.ResponseAuthenticationData = Encoding.UTF8.GetBytes("outcome of authentication");
-                        args.ReasonCode = MqttConnectReasonCode.Success;
-                        args.ReasonString = "Authentication successful";
-                    }
-                    else
-                    {
-                        args.ReasonCode = MqttConnectReasonCode.BadAuthenticationMethod;
-                    }
-                };
-
-                var clientOptions = testEnvironment.CreateDefaultClientOptionsBuilder().WithAuthentication("GS2-KRB5", new byte[0]).WithExtendedAuthenticationExchangeHandler(kerberosAuthenticationHandler);
-                var client = await testEnvironment.ConnectClient(clientOptions);
-
-                Assert.IsTrue(client.IsConnected);
-            }
-        }
-
-        [TestMethod]
-        public async Task No_Unobserved_Exception()
-        {
-            using (var testEnvironment = CreateTestEnvironment())
-            {
-                testEnvironment.IgnoreClientLogErrors = true;
-
-                var client = testEnvironment.CreateClient();
-                var options = new MqttClientOptionsBuilder().WithTcpServer("1.2.3.4").WithTimeout(TimeSpan.FromSeconds(2)).Build();
-
-                try
-                {
-                    using (var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(0.5)))
-                    {
-                        await client.ConnectAsync(options, timeout.Token);
-                    }
-                }
-                catch (OperationCanceledException)
-                {
-                }
-
-                client.Dispose();
-
-                // These delays and GC calls are required in order to make calling the finalizer reproducible.
-                GC.Collect();
-                GC.WaitForPendingFinalizers();
-                await LongTestDelay();
-                await LongTestDelay();
-                await LongTestDelay();
-            }
-        }
-
         [TestMethod]
         public async Task Return_Non_Success()
         {
@@ -316,25 +231,15 @@ namespace MQTTnet.Tests.Clients.MqttClient
         }
 
         [TestMethod]
-        public async Task Throw_Proper_Exception_When_Not_Connected()
+        [ExpectedException(typeof(MqttClientDisconnectedException))]
+        public async Task Rpc_Client_Not_Connected()
         {
-            try
+            var factory = new MqttFactory();
+            using (var client = factory.CreateMqttClient())
             {
-                var mqttFactory = new MqttFactory();
-                using (var mqttClient = mqttFactory.CreateMqttClient())
-                {
-                    await mqttClient.SubscribeAsync("test", MqttQualityOfServiceLevel.AtLeastOnce);
-                }
+                var rpcClient = factory.CreateMqttRpcClient(client);
+                await rpcClient.ExecuteAsync("aaa", new byte[] { 1, 2, 3 }, MqttQualityOfServiceLevel.AtLeastOnce);
             }
-            catch (MqttClientNotConnectedException exception)
-            {
-                if (exception.Message == "The MQTT client is not connected.")
-                {
-                    return;
-                }
-            }
-
-            Assert.Fail();
         }
     }
 }

Source/MQTTnet.Tests/Clients/MqttClient/MqttClient_Publish_Tests.cs

@@ -0,0 +1,59 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using MQTTnet.Client;
+using MQTTnet.Protocol;
+using MQTTnet.Server;
+
+namespace MQTTnet.Tests.Clients.MqttClient
+{
+    [TestClass]
+    public sealed class MqttClient_Publish_Tests : BaseTestClass
+    {
+        [TestMethod]
+        public async Task Acknowledge_After_Disconnect_Should_Fail()
+        {
+            using (var testEnvironment = CreateTestEnvironment())
+            {
+                var server = await testEnvironment.StartServer();
+
+                var client = await testEnvironment.ConnectClient();
+                await client.SubscribeAsync("TEST", MqttQualityOfServiceLevel.AtLeastOnce);
+
+                var flag = false;
+                
+                client.ApplicationMessageReceivedAsync += async args =>
+                {
+                    try
+                    {
+                        args.AutoAcknowledge = false;
+                        
+                        await client.DisconnectAsync();
+                        await args.AcknowledgeAsync();
+
+                        flag = true;
+                    }
+                    catch (Exception exception)
+                    {
+                        
+                    }
+                };
+
+                await server.InjectApplicationMessageAsync(
+                    new MqttApplicationMessage
+                    {
+                        Topic = "TEST"
+                    });
+
+                SpinWait.SpinUntil(() => flag, TimeSpan.FromSeconds(10));
+                
+                Assert.IsTrue(flag);
+            }
+        }
+    }
+}

Source/MQTTnet.Tests/Clients/MqttClient/MqttClient_Tests.cs

@@ -6,7 +6,6 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
-using System.Net;
 using System.Net.Sockets;
 using System.Text;
 using System.Threading;
@@ -18,7 +17,6 @@ using MQTTnet.Formatter;
 using MQTTnet.Internal;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
-using MQTTnet.Server;
 using MQTTnet.Tests.Mockups;
 
 // ReSharper disable InconsistentNaming
@@ -71,38 +69,8 @@ namespace MQTTnet.Tests.Clients.MqttClient
                 Assert.IsTrue(success);
             }
         }
+       
 
-        [TestMethod]
-        public async Task Connect_Disconnect_Connect()
-        {
-            using (var testEnvironment = CreateTestEnvironment())
-            {
-                await testEnvironment.StartServer();
-
-                var clientOptions = testEnvironment.CreateDefaultClientOptions();
-                var client = testEnvironment.CreateClient();
-
-                await client.ConnectAsync(clientOptions);
-                await client.DisconnectAsync();
-                await client.ConnectAsync(clientOptions);
-            }
-        }
-
-        [TestMethod]
-        [ExpectedException(typeof(InvalidOperationException))]
-        public async Task Connect_Multiple_Times_Should_Fail()
-        {
-            using (var testEnvironment = CreateTestEnvironment())
-            {
-                await testEnvironment.StartServer();
-
-                var clientOptions = testEnvironment.CreateDefaultClientOptions();
-                var client = testEnvironment.CreateClient();
-
-                await client.ConnectAsync(clientOptions);
-                await client.ConnectAsync(clientOptions);
-            }
-        }
 
         [TestMethod]
         public async Task Disconnect_Event_Contains_Exception()
@@ -298,7 +266,7 @@ namespace MQTTnet.Tests.Clients.MqttClient
 
                 Assert.IsNotNull(receivedMessage);
                 Assert.AreEqual("A", receivedMessage.Topic);
-                Assert.AreEqual(null, receivedMessage.PayloadSegment.Array);
+                Assert.AreEqual(null, receivedMessage.Payload);
             }
         }
 
@@ -509,7 +477,7 @@ namespace MQTTnet.Tests.Clients.MqttClient
 
                 client2.ApplicationMessageReceivedAsync += e =>
                 {
-                    client2TopicResults.Add(Encoding.UTF8.GetString(e.ApplicationMessage.PayloadSegment.ToArray()));
+                    client2TopicResults.Add(Encoding.UTF8.GetString(e.ApplicationMessage.Payload));
                     return CompletedTask.Instance;
                 };
 
@@ -749,8 +717,8 @@ namespace MQTTnet.Tests.Clients.MqttClient
                 {
                     if (e.ApplicationMessage.Topic == "request")
                     {
-                        // Use AtMostOnce here because with QoS 1 or even QoS 2 the process waits for
-                        // the ACK etc. The problem is that the SpinUntil below only waits until the
+                        // Use AtMostOnce here because with QoS 1 or even QoS 2 the process waits for 
+                        // the ACK etc. The problem is that the SpinUntil below only waits until the 
                         // flag is set. It does not wait until the client has sent the ACK
                         await client2.PublishStringAsync("reply");
                     }
@@ -926,54 +894,5 @@ namespace MQTTnet.Tests.Clients.MqttClient
                 Assert.IsFalse(disconnectedFired);
             }
         }
-
-        [TestMethod]
-        public void Backward_compatible_TCP_options()
-        {
-            var options = new MqttClientOptionsBuilder().WithTcpServer("host", 3).Build();
-
-            Assert.AreEqual("host", ((MqttClientTcpOptions)options.ChannelOptions).Server);
-            Assert.AreEqual(3, ((MqttClientTcpOptions)options.ChannelOptions).Port);
-
-            options = new MqttClientOptions
-            {
-                ChannelOptions = new MqttClientTcpOptions
-                {
-                    Server = "host",
-                    Port = 3
-                }
-            };
-
-            Assert.AreEqual("host:3", options.ChannelOptions.ToString());
-            Assert.AreEqual("host", ((MqttClientTcpOptions)options.ChannelOptions).Server);
-            Assert.AreEqual(3, ((MqttClientTcpOptions)options.ChannelOptions).Port);
-
-            options = new MqttClientOptionsBuilder().WithEndPoint(new DnsEndPoint("host", 3)).Build();
-            Assert.AreEqual("Unspecified/host:3", options.ChannelOptions.ToString());
-            Assert.AreEqual("host", ((MqttClientTcpOptions)options.ChannelOptions).Server);
-            Assert.AreEqual(3, ((MqttClientTcpOptions)options.ChannelOptions).Port);
-
-            options = new MqttClientOptionsBuilder().WithTcpServer("host").Build();
-
-            Assert.AreEqual("host", ((MqttClientTcpOptions)options.ChannelOptions).Server);
-            Assert.AreEqual(1883, ((MqttClientTcpOptions)options.ChannelOptions).Port);
-            Assert.AreEqual("Unspecified/host:1883", options.ChannelOptions.ToString());
-
-            options = new MqttClientOptionsBuilder().WithTlsOptions(o => o.UseTls()).WithTcpServer("host").Build();
-
-            Assert.AreEqual("host", ((MqttClientTcpOptions)options.ChannelOptions).Server);
-            Assert.AreEqual(8883, ((MqttClientTcpOptions)options.ChannelOptions).Port);
-
-            options = new MqttClientOptions
-            {
-                ChannelOptions = new MqttClientTcpOptions
-                {
-                    Server = "host"
-                }
-            };
-
-            Assert.AreEqual("host", ((MqttClientTcpOptions)options.ChannelOptions).Server);
-            Assert.AreEqual(null, ((MqttClientTcpOptions)options.ChannelOptions).Port);
-        }
     }
 }

Source/MQTTnet.Tests/Clients/MqttClientOptionsBuilder_Tests.cs

@@ -10,7 +10,7 @@ using MQTTnet.Client;
 namespace MQTTnet.Tests.Clients
 {
     [TestClass]
-    public class MqttClientOptionsBuilder_Tests
+    public sealed class MqttClientOptionsBuilder_Tests
     {
         [TestMethod]
         public void WithConnectionUri_Credential_Test()

Source/MQTTnet.Tests/Extensions/MqttTopicTemplate_Tests.cs

@@ -1,273 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-using System.Linq;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-using MQTTnet.Exceptions;
-using MQTTnet.Extensions.TopicTemplate;
-
-namespace MQTTnet.Tests.Extensions
-{
-    [TestClass]
-    public sealed class MqttTopicTemplate_Tests
-    {
-        [TestMethod]
-        public void BasicOps()
-        {
-            var template = new MqttTopicTemplate("A/B/{param}/D");
-            Assert.AreEqual("A/B/C/D", template.WithParameter("param", "C").Template);
-            Assert.AreEqual("A/B/+/D", template.WithoutParameter("param").Template);
-            Assert.AreEqual("A/B/+/D", template.TopicFilter);
-            Assert.AreEqual("A/B/+/D/#", template.TopicTreeRootFilter);
-
-            // corner cases
-            Assert.AreEqual("#", new MqttTopicTemplate("#").TopicFilter);
-            Assert.AreEqual("+", new MqttTopicTemplate("+").TopicFilter);
-            Assert.AreEqual("/", new MqttTopicTemplate("/").TopicFilter);
-        }
-
-        [TestMethod]
-        public void BasicOpsWithHash()
-        {
-            var template = new MqttTopicTemplate("A/B/{param}/D/#");
-            Assert.AreEqual("A/B/C/D/#", template.WithParameter("param", "C").Template);
-            Assert.AreEqual("A/B/+/D/#", template.WithoutParameter("param").Template);
-            Assert.AreEqual("A/B/+/D/#", template.TopicFilter);
-            Assert.AreEqual("A/B/+/D/#", template.TopicTreeRootFilter);
-        }
-
-        [TestMethod]
-        [ExpectedException(typeof(ArgumentException))]
-        public void RejectsReservedChars1()
-        {
-            var template = new MqttTopicTemplate("A/B/{foo}/D");
-            template.WithParameter("foo", "a#");
-        }
-
-        [TestMethod]
-        [ExpectedException(typeof(ArgumentException))]
-        public void RejectsReservedChars2()
-        {
-            var template = new MqttTopicTemplate("A/B/{foo}/D");
-            template.WithParameter("foo", "a+b");
-        }
-
-        [TestMethod]
-        [ExpectedException(typeof(ArgumentException))]
-        public void RejectsReservedChars3()
-        {
-            var template = new MqttTopicTemplate("A/B/{foo}/D");
-            template.WithParameter("foo", "a/b");
-        }
-        
-        [TestMethod]
-        public void AcceptsEmptyValue()
-        {
-            var template = new MqttTopicTemplate("A/B/{foo}/D");
-            template.WithParameter("foo", "");
-        }
-        
-        [TestMethod]
-        [ExpectedException(typeof(MqttProtocolViolationException))]
-        public void RejectsEmptyTemplate()
-        {
-            var _ = new MqttTopicTemplate("");
-        }
-        
-        [TestMethod]
-        [ExpectedException(typeof(ArgumentNullException))]
-        public void RejectsNullTemplate()
-        {
-            var _ = new MqttTopicTemplate(null);
-        }
-
-        
-        [TestMethod]
-        public void IgnoresEmptyParameters()
-        {
-            var template = new MqttTopicTemplate("A/B/{}/D");
-            Assert.IsFalse(template.Parameters.Any());
-        }
-        
-        [TestMethod]
-        public void AcceptsValidTopics()
-        {
-            _ = new MqttTopicTemplate("A");
-            _ = new MqttTopicTemplate("/");
-            _ = new MqttTopicTemplate("/A");
-            _ = new MqttTopicTemplate("A/#");
-            _ = new MqttTopicTemplate("$SYS/#");
-            _ = new MqttTopicTemplate("////");
-            _ = new MqttTopicTemplate("A/B/{foo}/D/");
-        }
-
-        [TestMethod]
-        public void DynamicRoutingSupport()
-        {
-            var v1template = new MqttTopicTemplate("A/v1/{id}/F");
-            var v2template = new MqttTopicTemplate("A/v2/foo/{id}/{bar}");
-            var incoming_v1_topic = "A/v1/32/F";
-
-            var compat_v2_topic = v2template
-                .WithParameterValuesFrom(
-                    v1template.ParseParameterValues(incoming_v1_topic))
-                .WithParameter("bar", "unknown");
-
-            // id: 32 was relocated and bar: unknown added
-            Assert.AreEqual("A/v2/foo/32/unknown", compat_v2_topic.Template);
-        }
-
-        [TestMethod]
-        public void SubscriptionSupport()
-        {
-            var template = new MqttTopicTemplate("A/v1/{param}/F");
-            var filter = template.BuildFilter()
-                .WithAtLeastOnceQoS()
-                .WithNoLocal()
-                .Build();
-            Assert.AreEqual("A/v1/+/F", filter.Topic);
-        }
-
-        [TestMethod]
-        public void SubscriptionSupport2()
-        {
-            var template = new MqttTopicTemplate("A/v1/{param}/F");
-            
-            var subscribeOptions = new MqttFactory().CreateSubscribeOptionsBuilder()
-                .WithTopicTemplate(template)
-                .WithSubscriptionIdentifier(5)
-                .Build();
-            Assert.AreEqual("A/v1/+/F", subscribeOptions.TopicFilters[0].Topic);
-        }
-
-        [TestMethod]
-        public void SendAndSubscribeSupport()
-        {
-            var template = new MqttTopicTemplate("App/v1/{sender}/message");
-
-            var filter = new MqttTopicFilterBuilder()
-                .WithTopicTemplate(template)
-                .WithAtLeastOnceQoS()
-                .WithNoLocal()
-                .Build();
-
-            Assert.AreEqual("App/v1/+/message", filter.Topic);
-
-            var myTopic = template.WithParameter("sender", "me, myself & i");
-
-            var message = new MqttApplicationMessageBuilder()
-                .WithTopicTemplate(
-                    myTopic)
-                .WithPayload("Hello!")
-                .Build();
-
-            Assert.IsTrue(message.MatchesTopicTemplate(template));
-        }
-
-        [TestMethod]
-        public void SendAndSubscribeSupport2()
-        {
-            var template = new MqttTopicTemplate("App/v1/{sender}/message");
-            Assert.ThrowsException<ArgumentException>(() => 
-                template.BuildMessage());
-        }
-
-        [TestMethod]
-        public void CanonicalPrefixFilter()
-        {
-            var template1 = new MqttTopicTemplate("A/v1/{param}/F");
-            var template2 = new MqttTopicTemplate("A/v1/E/F");
-            var template3 = new MqttTopicTemplate("A/v1/E/F/G/H");
-            var canonicalFilter = MqttTopicTemplate.FindCanonicalPrefix(new[] { template1, template2, template3 });
-            // possible improvement: Assert.AreEqual("A/v1/+/F", canonicalFilter.TopicFilter);
-            Assert.AreEqual("A/v1/+", canonicalFilter.TopicFilter);
-            Assert.AreEqual("A/v1/+/#", canonicalFilter.TopicTreeRootFilter);
-            
-            var template2b = new MqttTopicTemplate("A/v1/E/X");
-            canonicalFilter = MqttTopicTemplate.FindCanonicalPrefix(new[] { template1, template2, template3, template2b });
-            Assert.AreEqual("A/v1/+", canonicalFilter.Template);
-            Assert.AreEqual("A/v1/+", canonicalFilter.TopicFilter);
-            Assert.AreEqual("A/v1/+/#", canonicalFilter.TopicTreeRootFilter);
-
-
-            var template4 = new MqttTopicTemplate("A/v2/{prefix}");
-            var canonicalFilter2 = MqttTopicTemplate.FindCanonicalPrefix(new[] { template1, template2, template3, template4 });
-            Assert.AreEqual("A/+", canonicalFilter2.TopicFilter);
-            Assert.AreEqual("A/+/#", canonicalFilter2.TopicTreeRootFilter);
-        }
-        
-        [TestMethod]
-        public void CanonicalPrefixFilterSimple1()
-        {
-            var template = MqttTopicTemplate.FindCanonicalPrefix(new[]
-            {
-                new MqttTopicTemplate("A"),
-                new MqttTopicTemplate("B")
-            });
-            Assert.AreEqual("#", template.TopicFilter);
-            Assert.AreEqual("#", template.Template);
-        }
-        
-        [TestMethod]
-        public void CanonicalPrefixFilterSimple2()
-        {
-            var template = MqttTopicTemplate.FindCanonicalPrefix(new[]
-            {
-                new MqttTopicTemplate("A/v1/{param}/F/"),
-                new MqttTopicTemplate("A/v1/E/X")
-            });
-            Assert.AreEqual("A/v1/+", template.TopicFilter);
-        }
-        
-        [TestMethod]
-        public void CanonicalPrefixFilterSimple3()
-        {
-            var template = MqttTopicTemplate.FindCanonicalPrefix(new[]
-            {
-                new MqttTopicTemplate("A/v1/{param}/F"),
-                new MqttTopicTemplate("A/v1/{param}/F/X")
-            });
-            Assert.AreEqual("A/v1/+/+", template.TopicFilter);
-            Assert.AreEqual("A/v1/{param}/+", template.Template);
-        }
-        
-        [TestMethod]
-        public void CanonicalPrefixFilterSimple4()
-        {
-            var template = MqttTopicTemplate.FindCanonicalPrefix(new[]
-            {
-                new MqttTopicTemplate("A/v1/{param}/FFA"),
-                new MqttTopicTemplate("A/v1/{param}/FX")
-            });
-            Assert.AreEqual("A/v1/+/+", template.TopicFilter);
-            Assert.AreEqual("A/v1/{param}/+", template.Template);
-        }
-        
-        
-        [TestMethod]
-        public void CanonicalPrefixFilterSimple5()
-        {
-            var template = MqttTopicTemplate.FindCanonicalPrefix(new[]
-            {
-                new MqttTopicTemplate("A/v1/E/F/G/H"),
-                new MqttTopicTemplate("A/v2/{param}")
-            });
-            Assert.AreEqual("A/+", template.TopicFilter);
-            Assert.AreEqual("A/+/#", template.TopicTreeRootFilter);
-        }
-        
-        [TestMethod]
-        public void CanonicalPrefixFilterSimple6()
-        {
-            var template = MqttTopicTemplate.FindCanonicalPrefix(new[]
-            {
-                new MqttTopicTemplate("A/{version}/E/F/G/H"),
-                new MqttTopicTemplate("A/{version}/{param}")
-            });
-            Assert.AreEqual("A/+/+", template.TopicFilter);
-            Assert.AreEqual("A/+/+/#", template.TopicTreeRootFilter);
-        }
-    }
-}

Source/MQTTnet.Tests/Extensions/Rpc_Tests.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Collections.Generic;
 using System.Text;
 using System.Threading.Tasks;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
@@ -46,34 +45,6 @@ namespace MQTTnet.Tests.Extensions
             }
         }
 
-        [TestMethod]
-        public async Task Execute_Success_Parameters_Propagated_Correctly()
-        {
-            var paramValue = "123";
-            var parameters = new Dictionary<string, object>
-            {
-                { TestParametersTopicGenerationStrategy.ExpectedParamName, "123" }
-            };
-
-            using (var testEnvironment = CreateTestEnvironment())
-            {
-                await testEnvironment.StartServer();
-
-                var responseSender = await testEnvironment.ConnectClient(new MqttClientOptionsBuilder());
-                await responseSender.SubscribeAsync($"MQTTnet.RPC/+/ping/{paramValue}");
-
-                responseSender.ApplicationMessageReceivedAsync += e => responseSender.PublishStringAsync(e.ApplicationMessage.Topic + "/response", "pong");
-
-                using (var rpcClient = await testEnvironment.ConnectRpcClient(new MqttRpcClientOptionsBuilder()
-                           .WithTopicGenerationStrategy(new TestParametersTopicGenerationStrategy()).Build()))
-                {
-                    var response = await rpcClient.ExecuteAsync(TimeSpan.FromSeconds(5), "ping", "", MqttQualityOfServiceLevel.AtMostOnce, parameters);
-
-                    Assert.AreEqual("pong", Encoding.UTF8.GetString(response));
-                }
-            }
-        }
-
         [TestMethod]
         public Task Execute_Success_With_QoS_0()
         {
@@ -164,7 +135,7 @@ namespace MQTTnet.Tests.Extensions
 
                 using (var rpcClient = new MqttRpcClient(requestSender, new MqttRpcClientOptionsBuilder().Build()))
                 {
-                    await rpcClient.ExecuteAsync(TimeSpan.FromSeconds(2), "ping", "", MqttQualityOfServiceLevel.AtMostOnce);
+                    var response = await rpcClient.ExecuteAsync(TimeSpan.FromSeconds(2), "ping", "", MqttQualityOfServiceLevel.AtMostOnce);
                 }
             }
         }
@@ -251,32 +222,5 @@ namespace MQTTnet.Tests.Extensions
                 };
             }
         }
-
-        class TestParametersTopicGenerationStrategy : IMqttRpcClientTopicGenerationStrategy
-        {
-            internal const string ExpectedParamName = "test_param_name";
-
-            public MqttRpcTopicPair CreateRpcTopics(TopicGenerationContext context)
-            {
-                if (context.Parameters == null)
-                {
-                    throw new InvalidOperationException("Parameters dictionary expected to be not null");
-                }
-
-                if (!context.Parameters.TryGetValue(ExpectedParamName, out var paramValue))
-                {
-                    throw new InvalidOperationException($"Parameter with name {ExpectedParamName} not present");
-                }
-
-                var requestTopic = $"MQTTnet.RPC/{Guid.NewGuid():N}/{context.MethodName}/{paramValue}";
-                var responseTopic = requestTopic + "/response";
-
-                return new MqttRpcTopicPair
-                {
-                    RequestTopic = requestTopic,
-                    ResponseTopic = responseTopic
-                };
-            }
-        }
     }
 }

Source/MQTTnet.Tests/Extensions/WebSocket4Net_Tests.cs

@@ -23,7 +23,7 @@ namespace MQTTnet.Tests.Extensions
 
             using (var client = factory.CreateMqttClient())
             {
-                var options = new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("ws://a.b/mqtt")).WithTimeout(TimeSpan.FromSeconds(2)).Build();
+                var options = new MqttClientOptionsBuilder().WithWebSocketServer("ws://a.b/mqtt").WithTimeout(TimeSpan.FromSeconds(2)).Build();
                 await client.ConnectAsync(options).ConfigureAwait(false);
             }
         }

Source/MQTTnet.Tests/Internal/CrossPlatformSocket_Tests.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Net.Sockets;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
@@ -18,7 +17,7 @@ namespace MQTTnet.Tests.Internal
         [TestMethod]
         public async Task Connect_Send_Receive()
         {
-            var crossPlatformSocket = new CrossPlatformSocket(ProtocolType.Tcp);
+            var crossPlatformSocket = new CrossPlatformSocket();
             await crossPlatformSocket.ConnectAsync("www.google.de", 80, CancellationToken.None);
 
             var requestBuffer = Encoding.UTF8.GetBytes("GET / HTTP/1.1\r\nHost: www.google.de\r\n\r\n");
@@ -37,7 +36,7 @@ namespace MQTTnet.Tests.Internal
         [ExpectedException(typeof(OperationCanceledException))]
         public async Task Try_Connect_Invalid_Host()
         {
-            var crossPlatformSocket = new CrossPlatformSocket(ProtocolType.Tcp);
+            var crossPlatformSocket = new CrossPlatformSocket();
 
             var cancellationToken = new CancellationTokenSource(TimeSpan.FromSeconds(5));
             cancellationToken.Token.Register(() => crossPlatformSocket.Dispose());
@@ -66,7 +65,7 @@ namespace MQTTnet.Tests.Internal
         [TestMethod]
         public void Set_Options()
         {
-            var crossPlatformSocket = new CrossPlatformSocket(ProtocolType.Tcp);
+            var crossPlatformSocket = new CrossPlatformSocket();
 
             Assert.IsFalse(crossPlatformSocket.ReuseAddress);
             crossPlatformSocket.ReuseAddress = true;

Source/MQTTnet.Tests/MQTTnet.Tests.csproj

@@ -1,8 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFrameworks>netcoreapp3.1;net7.0</TargetFrameworks>
-        <TargetFrameworks Condition=" '$(OS)' == 'Windows_NT' ">$(TargetFrameworks);net452;net48</TargetFrameworks>
+        <TargetFrameworks>net452;net461;net48;netcoreapp3.1;net6.0;net7.0</TargetFrameworks>
         <IsPackable>false</IsPackable>
         <LangVersion>7.3</LangVersion>
         <EnableNETAnalyzers>false</EnableNETAnalyzers>
@@ -21,7 +20,6 @@
         <ProjectReference Include="..\..\Source\MQTTnet.Extensions.ManagedClient\MQTTnet.Extensions.ManagedClient.csproj" />
         <ProjectReference Include="..\..\Source\MQTTnet.Extensions.Rpc\MQTTnet.Extensions.Rpc.csproj" />
         <ProjectReference Include="..\..\Source\MQTTnet\MQTTnet.csproj" />
-        <ProjectReference Include="..\MQTTnet.Extensions.TopicTemplate\MQTTnet.Extensions.TopicTemplate.csproj" />
         <ProjectReference Include="..\MQTTnet.Extensions.WebSocket4Net\MQTTnet.Extensions.WebSocket4Net.csproj" />
     </ItemGroup>
 

Source/MQTTnet.Tests/MQTTv5/Client_Tests.cs

@@ -273,7 +273,7 @@ namespace MQTTnet.Tests.MQTTv5
                 Assert.AreEqual(applicationMessage.ResponseTopic, receivedMessage.ResponseTopic);
                 Assert.AreEqual(applicationMessage.MessageExpiryInterval, receivedMessage.MessageExpiryInterval);
                 CollectionAssert.AreEqual(applicationMessage.CorrelationData, receivedMessage.CorrelationData);
-                CollectionAssert.AreEqual(applicationMessage.PayloadSegment.ToArray(), receivedMessage.PayloadSegment.ToArray());
+                CollectionAssert.AreEqual(applicationMessage.Payload, receivedMessage.Payload);
                 CollectionAssert.AreEqual(applicationMessage.UserProperties, receivedMessage.UserProperties);
             }
         }

Source/MQTTnet.Tests/MQTTv5/Server_Tests.cs

@@ -10,7 +10,6 @@ using System.Threading;
 using System.Threading.Tasks;
 using MQTTnet.Internal;
 using MQTTnet.Protocol;
-using MQTTnet.Server;
 
 namespace MQTTnet.Tests.MQTTv5
 {

Source/MQTTnet.Tests/Mockups/TestEnvironment.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
@@ -24,9 +25,9 @@ namespace MQTTnet.Tests.Mockups
     public sealed class TestEnvironment : IDisposable
     {
         readonly List<string> _clientErrors = new List<string>();
-        readonly List<IMqttClient> _clients = new List<IMqttClient>();
+        readonly ConcurrentBag<IMqttClient> _clients = new ConcurrentBag<IMqttClient>();
         readonly List<Exception> _exceptions = new List<Exception>();
-        readonly List<ILowLevelMqttClient> _lowLevelClients = new List<ILowLevelMqttClient>();
+        readonly ConcurrentBag<ILowLevelMqttClient> _lowLevelClients = new ConcurrentBag<ILowLevelMqttClient>();
         readonly MqttProtocolVersion _protocolVersion;
         readonly List<string> _serverErrors = new List<string>();
 
@@ -39,8 +40,6 @@ namespace MQTTnet.Tests.Mockups
             _protocolVersion = protocolVersion;
             TestContext = testContext;
 
-            TaskScheduler.UnobservedTaskException += TrackUnobservedTaskException;
-
             ServerLogger.LogMessagePublished += (s, e) =>
             {
                 if (Debugger.IsAttached)
@@ -217,9 +216,8 @@ namespace MQTTnet.Tests.Mockups
         public IMqttClient CreateClient()
         {
             var logger = EnableLogger ? (IMqttNetLogger)ClientLogger : MqttNetNullLogger.Instance;
-
+            
             var client = Factory.CreateMqttClient(logger);
-
             client.ConnectingAsync += e =>
             {
                 if (TestContext != null)
@@ -234,12 +232,9 @@ namespace MQTTnet.Tests.Mockups
 
                 return CompletedTask.Instance;
             };
-
-            lock (_clients)
-            {
-                _clients.Add(client);
-            }
-
+            
+            _clients.Add(client);
+            
             return client;
         }
 
@@ -250,20 +245,13 @@ namespace MQTTnet.Tests.Mockups
 
         public MqttClientOptionsBuilder CreateDefaultClientOptionsBuilder()
         {
-            return Factory.CreateClientOptionsBuilder()
-                .WithProtocolVersion(_protocolVersion)
-                .WithTcpServer("127.0.0.1", ServerPort)
-                .WithClientId(TestContext.TestName + "_" + Guid.NewGuid());
+            return Factory.CreateClientOptionsBuilder().WithProtocolVersion(_protocolVersion).WithTcpServer("127.0.0.1", ServerPort).WithClientId(TestContext.TestName + "_" + Guid.NewGuid());
         }
 
         public ILowLevelMqttClient CreateLowLevelClient()
         {
             var client = Factory.CreateLowLevelMqttClient(ClientLogger);
-
-            lock (_lowLevelClients)
-            {
-                _lowLevelClients.Add(client);
-            }
+            _lowLevelClients.Add(client);
 
             return client;
         }
@@ -299,68 +287,45 @@ namespace MQTTnet.Tests.Mockups
 
         public void Dispose()
         {
-            try
+            foreach (var mqttClient in _clients)
             {
-                lock (_clients)
-                {
-                    foreach (var mqttClient in _clients)
-                    {
-                        try
-                        {
-                            //mqttClient.DisconnectAsync().GetAwaiter().GetResult();
-                        }
-                        catch
-                        {
-                            // This can happen when the test already disconnected the client.
-                        }
-                        finally
-                        {
-                            mqttClient?.Dispose();
-                        }
-                    }
-
-                    _clients.Clear();
-                }
-
-                lock (_lowLevelClients)
-                {
-                    foreach (var lowLevelMqttClient in _lowLevelClients)
-                    {
-                        lowLevelMqttClient.Dispose();
-                    }
-
-                    _lowLevelClients.Clear();
-                }
-
                 try
                 {
-                    Server?.StopAsync().GetAwaiter().GetResult();
+                    //mqttClient.DisconnectAsync().GetAwaiter().GetResult();
                 }
                 catch
                 {
-                    // This can happen when the test already stopped the server.
+                    // This can happen when the test already disconnected the client.
                 }
                 finally
                 {
-                    Server?.Dispose();
+                    mqttClient?.Dispose();
                 }
+            }
 
-                Server = null;
+            foreach (var lowLevelMqttClient in _lowLevelClients)
+            {
+                lowLevelMqttClient.Dispose();
+            }
 
-                ThrowIfLogErrors();
-
-                GC.Collect();
-                GC.WaitForFullGCComplete();
-                GC.WaitForPendingFinalizers();
-                
-                if (_exceptions.Any())
-                {
-                    throw new Exception($"{_exceptions.Count} exceptions tracked.\r\n" + string.Join(Environment.NewLine, _exceptions));
-                }
+            try
+            {
+                Server?.StopAsync().GetAwaiter().GetResult();
+            }
+            catch
+            {
+                // This can happen when the test already stopped the server.
             }
             finally
             {
-                TaskScheduler.UnobservedTaskException -= TrackUnobservedTaskException;
+                Server?.Dispose();
+            }
+
+            ThrowIfLogErrors();
+
+            if (_exceptions.Any())
+            {
+                throw new Exception($"{_exceptions.Count} exceptions tracked.\r\n" + string.Join(Environment.NewLine, _exceptions));
             }
         }
 
@@ -377,7 +342,7 @@ namespace MQTTnet.Tests.Mockups
 
             var options = optionsBuilder.Build();
             var server = CreateServer(options);
-            await server.StartAsync().ConfigureAwait(false);
+            await server.StartAsync();
 
             // The OS has chosen the port to we have to properly expose it to the tests.
             ServerPort = options.DefaultEndpointOptions.Port;
@@ -405,16 +370,13 @@ namespace MQTTnet.Tests.Mockups
 
         public void ThrowIfLogErrors()
         {
-            if (!IgnoreServerLogErrors)
+            lock (_serverErrors)
             {
-                lock (_serverErrors)
+                if (!IgnoreServerLogErrors && _serverErrors.Count > 0)
                 {
-                    if (_serverErrors.Count > 0)
-                    {
-                        var message = $"Server had {_serverErrors.Count} errors (${string.Join(Environment.NewLine, _serverErrors)}).";
-                        Console.WriteLine(message);
-                        throw new Exception(message);
-                    }
+                    var message = $"Server had {_serverErrors.Count} errors (${string.Join(Environment.NewLine, _serverErrors)}).";
+                    Console.WriteLine(message);
+                    throw new Exception(message);
                 }
             }
 
@@ -434,20 +396,10 @@ namespace MQTTnet.Tests.Mockups
 
         public void TrackException(Exception exception)
         {
-            if (exception == null)
-            {
-                return;
-            }
-
             lock (_exceptions)
             {
                 _exceptions.Add(exception);
             }
         }
-
-        void TrackUnobservedTaskException(object sender, UnobservedTaskExceptionEventArgs e)
-        {
-            TrackException(e.Exception);
-        }
     }
 }

Source/MQTTnet.Tests/MqttApplicationMessageBuilder_Tests.cs

@@ -4,7 +4,6 @@
 
 using System;
 using System.IO;
-using System.Linq;
 using System.Text;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Protocol;
@@ -12,7 +11,7 @@ using MQTTnet.Protocol;
 namespace MQTTnet.Tests
 {
     [TestClass]
-    public sealed class MqttApplicationMessageBuilder_Tests
+    public class MqttApplicationMessageBuilder_Tests
     {
         [TestMethod]
         public void CreateApplicationMessage_TopicOnly()
@@ -30,7 +29,7 @@ namespace MQTTnet.Tests
             Assert.AreEqual("xyz", message.Topic);
             Assert.IsFalse(message.Retain);
             Assert.AreEqual(MqttQualityOfServiceLevel.AtMostOnce, message.QualityOfServiceLevel);
-            Assert.AreEqual(Encoding.UTF8.GetString(message.PayloadSegment.ToArray()), "00:06:00");
+            Assert.AreEqual(Encoding.UTF8.GetString(message.Payload), "00:06:00");
         }
 
         [TestMethod]
@@ -42,7 +41,7 @@ namespace MQTTnet.Tests
             Assert.AreEqual("123", message.Topic);
             Assert.IsFalse(message.Retain);
             Assert.AreEqual(MqttQualityOfServiceLevel.AtMostOnce, message.QualityOfServiceLevel);
-            Assert.AreEqual(Encoding.UTF8.GetString(message.PayloadSegment.ToArray()), "Hello");
+            Assert.AreEqual(Encoding.UTF8.GetString(message.Payload), "Hello");
         }
 
         [TestMethod]

Source/MQTTnet.Tests/MqttApplicationMessageTest.cs

@@ -1,5 +1,3 @@
-#pragma warning disable CS0618 // Type or member is obsolete
-
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using System;
 using System.Collections.Generic;
@@ -10,7 +8,7 @@ using System.Threading.Tasks;
 namespace MQTTnet.Tests
 {
     [TestClass]
-    public sealed class MqttApplicationMessageTest
+    public class MqttApplicationMessageTest
     {
         [TestMethod]
         public void PayloadSegment()
@@ -19,27 +17,32 @@ namespace MQTTnet.Tests
             Assert.AreEqual(0, message.Payload.Length);
             Assert.AreEqual(0, message.PayloadSegment.Count);
 
-            Assert.IsTrue(ReferenceEquals(message.Payload, message.PayloadSegment.Array));
+            Assert.IsTrue(object.ReferenceEquals(message.Payload, message.Payload));
+            Assert.IsTrue(object.ReferenceEquals(message.Payload, message.PayloadSegment.Array));
 
             message.Payload = new byte[] { 1, 2 };
             Assert.AreEqual(2, message.Payload.Length);
             Assert.AreEqual(2, message.PayloadSegment.Count);
-            Assert.IsTrue(ReferenceEquals(message.Payload, message.PayloadSegment.Array));
+            Assert.IsTrue(object.ReferenceEquals(message.Payload, message.Payload));
+            Assert.IsTrue(object.ReferenceEquals(message.Payload, message.PayloadSegment.Array));
 
             message.Payload = new byte[] { 1, 2, 3 };
             Assert.AreEqual(3, message.Payload.Length);
             Assert.AreEqual(3, message.PayloadSegment.Count);
-            Assert.IsTrue(ReferenceEquals(message.Payload, message.PayloadSegment.Array));
+            Assert.IsTrue(object.ReferenceEquals(message.Payload, message.Payload));
+            Assert.IsTrue(object.ReferenceEquals(message.Payload, message.PayloadSegment.Array));
 
             message.PayloadSegment = new ArraySegment<byte>(new byte[] { 1, 2, 3 });
             Assert.AreEqual(3, message.Payload.Length);
             Assert.AreEqual(3, message.PayloadSegment.Count);
-            Assert.IsTrue(ReferenceEquals(message.Payload, message.PayloadSegment.Array));
+            Assert.IsTrue(object.ReferenceEquals(message.Payload, message.Payload));
+            Assert.IsTrue(object.ReferenceEquals(message.Payload, message.PayloadSegment.Array));
 
             message.PayloadSegment = new ArraySegment<byte>(new byte[] { 1, 2, 3 }, 1, 1);
             Assert.AreEqual(1, message.Payload.Length);
             Assert.AreEqual(1, message.PayloadSegment.Count);
-            Assert.IsFalse(ReferenceEquals(message.Payload, message.PayloadSegment.Array));
+            Assert.IsTrue(object.ReferenceEquals(message.Payload, message.Payload));
+            Assert.IsFalse(object.ReferenceEquals(message.Payload, message.PayloadSegment.Array));
         }
     }
 }

Source/MQTTnet.Tests/MqttTcpChannel_Tests.cs

@@ -2,13 +2,13 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using MQTTnet.Implementations;
 using System;
 using System.Net;
 using System.Net.Sockets;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-using MQTTnet.Implementations;
 
 namespace MQTTnet.Tests
 {
@@ -18,68 +18,62 @@ namespace MQTTnet.Tests
         [TestMethod]
         public async Task Dispose_Channel_While_Used()
         {
-            using (var ct = new CancellationTokenSource())
+            var ct = new CancellationTokenSource();
+            var serverSocket = new CrossPlatformSocket(AddressFamily.InterNetwork);
+
+            try
             {
-                using (var serverSocket = new CrossPlatformSocket(AddressFamily.InterNetwork, ProtocolType.Tcp))
+                serverSocket.Bind(new IPEndPoint(IPAddress.Any, 50001));
+                serverSocket.Listen(0);
+
+#pragma warning disable 4014
+                Task.Run(async () =>
+#pragma warning restore 4014
                 {
-                    try
+                    while (!ct.IsCancellationRequested)
                     {
-                        serverSocket.Bind(new IPEndPoint(IPAddress.Any, 50001));
-                        serverSocket.Listen(0);
-
-#pragma warning disable 4014
-                        Task.Run(
-                            async () =>
-#pragma warning restore 4014
-                            {
-                                while (!ct.IsCancellationRequested)
-                                {
-                                    var client = await serverSocket.AcceptAsync(ct.Token);
-                                    var data = new byte[] { 128 };
-                                    await client.SendAsync(new ArraySegment<byte>(data), SocketFlags.None);
-                                }
-                            },
-                            ct.Token);
-
-                        var clientSocket = new CrossPlatformSocket(AddressFamily.InterNetwork, ProtocolType.Tcp);
-                        await clientSocket.ConnectAsync("localhost", 50001, CancellationToken.None);
-
-                        var tcpChannel = new MqttTcpChannel(clientSocket.GetStream(), "test", null);
-
-                        await Task.Delay(100, ct.Token);
-
-                        var buffer = new byte[1];
-                        await tcpChannel.ReadAsync(buffer, 0, 1, ct.Token);
-
-                        Assert.AreEqual(128, buffer[0]);
-
-                        // This block should fail after dispose.
-#pragma warning disable 4014
-                        Task.Run(
-                            () =>
-#pragma warning restore 4014
-                            {
-                                Task.Delay(200, ct.Token);
-                                tcpChannel.Dispose();
-                            },
-                            ct.Token);
-
-                        try
-                        {
-                            await tcpChannel.ReadAsync(buffer, 0, 1, CancellationToken.None);
-                        }
-                        catch (Exception exception)
-                        {
-                            Assert.IsInstanceOfType(exception, typeof(SocketException));
-                            Assert.AreEqual(SocketError.OperationAborted, ((SocketException)exception).SocketErrorCode);
-                        }
-                    }
-                    finally
-                    {
-                        ct.Cancel(false);
+                        var client = await serverSocket.AcceptAsync();
+                        var data = new byte[] { 128 };
+                        await client.SendAsync(new ArraySegment<byte>(data), SocketFlags.None);
                     }
+                }, ct.Token);
+
+                var clientSocket = new CrossPlatformSocket(AddressFamily.InterNetwork);
+                await clientSocket.ConnectAsync("localhost", 50001, CancellationToken.None);
+
+                var tcpChannel = new MqttTcpChannel(clientSocket.GetStream(), "test", null);
+
+                await Task.Delay(100, ct.Token);
+
+                var buffer = new byte[1];
+                await tcpChannel.ReadAsync(buffer, 0, 1, ct.Token);
+
+                Assert.AreEqual(128, buffer[0]);
+
+                // This block should fail after dispose.
+#pragma warning disable 4014
+                Task.Run(() =>
+#pragma warning restore 4014
+                {
+                    Task.Delay(200, ct.Token);
+                    tcpChannel.Dispose();
+                }, ct.Token);
+
+                try
+                {
+                    await tcpChannel.ReadAsync(buffer, 0, 1, CancellationToken.None);
                 }
+                catch (Exception exception)
+                {
+                    Assert.IsInstanceOfType(exception, typeof(SocketException));
+                    Assert.AreEqual(SocketError.OperationAborted, ((SocketException)exception).SocketErrorCode);
+                }
+            }
+            finally
+            {
+                ct.Cancel(false);
+                serverSocket.Dispose();
             }
         }
     }
-}
+}

Source/MQTTnet.Tests/Server/Connection_Tests.cs

@@ -23,7 +23,7 @@ namespace MQTTnet.Tests.Server
             {
                 await testEnvironment.StartServer(new MqttServerOptionsBuilder().WithDefaultCommunicationTimeout(TimeSpan.FromSeconds(1)));
 
-                var client = new CrossPlatformSocket(AddressFamily.InterNetwork, ProtocolType.Tcp);
+                var client = new CrossPlatformSocket(AddressFamily.InterNetwork);
                 await client.ConnectAsync("localhost", testEnvironment.ServerPort, CancellationToken.None);
 
                 // Don't send anything. The server should close the connection.
@@ -54,7 +54,7 @@ namespace MQTTnet.Tests.Server
 
                 // Send an invalid packet and ensure that the server will close the connection and stay in a waiting state
                 // forever. This is security related.
-                var client = new CrossPlatformSocket(AddressFamily.InterNetwork, ProtocolType.Tcp);
+                var client = new CrossPlatformSocket(AddressFamily.InterNetwork);
                 await client.ConnectAsync("localhost", testEnvironment.ServerPort, CancellationToken.None);
 
                 var buffer = Encoding.UTF8.GetBytes("Garbage");

Source/MQTTnet.Tests/Server/General.cs

@@ -303,7 +303,7 @@ namespace MQTTnet.Tests.Server
                 var server = await testEnvironment.StartServer();
                 server.InterceptingPublishAsync += e =>
                 {
-                    e.ApplicationMessage.PayloadSegment = new ArraySegment<byte>(Encoding.ASCII.GetBytes("extended"));
+                    e.ApplicationMessage.Payload = Encoding.ASCII.GetBytes("extended");
                     return CompletedTask.Instance;
                 };
 
@@ -314,7 +314,7 @@ namespace MQTTnet.Tests.Server
                 var isIntercepted = false;
                 c2.ApplicationMessageReceivedAsync += e =>
                 {
-                    isIntercepted = string.Compare("extended", Encoding.UTF8.GetString(e.ApplicationMessage.PayloadSegment.ToArray()), StringComparison.Ordinal) == 0;
+                    isIntercepted = string.Compare("extended", Encoding.UTF8.GetString(e.ApplicationMessage.Payload), StringComparison.Ordinal) == 0;
                     return CompletedTask.Instance;
                 };
 
@@ -425,7 +425,7 @@ namespace MQTTnet.Tests.Server
                             new MqttApplicationMessage
                             {
                                 Topic = "/test/1",
-                                PayloadSegment = new ArraySegment<byte>(Encoding.UTF8.GetBytes("true")),
+                                Payload = Encoding.UTF8.GetBytes("true"),
                                 QualityOfServiceLevel = MqttQualityOfServiceLevel.ExactlyOnce
                             })
                         {
@@ -780,7 +780,7 @@ namespace MQTTnet.Tests.Server
                 var client1 = await testEnvironment.ConnectClient();
                 client1.ApplicationMessageReceivedAsync += e =>
                 {
-                    receivedBody = e.ApplicationMessage.PayloadSegment.ToArray();
+                    receivedBody = e.ApplicationMessage.Payload;
                     return CompletedTask.Instance;
                 };
 

Source/MQTTnet.Tests/Server/HotSwapCerts_Tests.cs

@@ -1,426 +0,0 @@
-#if !(NET452 || NET461 || NET48)
-using System;
-using System.Collections.Concurrent;
-using System.Diagnostics;
-using System.Linq;
-using System.Net;
-using System.Net.Security;
-using System.Security.Authentication;
-using System.Security.Cryptography;
-using System.Security.Cryptography.X509Certificates;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-using MQTTnet.Certificates;
-using MQTTnet.Client;
-using MQTTnet.Formatter;
-using MQTTnet.Protocol;
-using MQTTnet.Server;
-
-namespace MQTTnet.Tests.Server
-{
-    // missing certificate builder api means tests won't work for older frameworks
-
-    [TestClass]
-    public sealed class HotSwapCerts_Tests
-    {
-        static readonly TimeSpan DefaultTimeout = TimeSpan.FromSeconds(10);
-
-        [TestMethod]
-        public async Task ClientCertChangeWithoutServerUpdateFailsReconnect()
-        {
-            using (var server = new ServerTestHarness())
-            using (var client01 = new ClientTestHarness())
-            {
-                server.InstallNewClientCert(client01.GetCurrentClientCert());
-                client01.InstallNewServerCert(server.GetCurrentServerCert());
-
-                await server.StartServer();
-
-                await client01.Connect();
-
-                client01.WaitForConnectOrFail(DefaultTimeout);
-
-                client01.HotSwapClientCert();
-                server.ForceDisconnectAsync(client01).Wait(DefaultTimeout);
-                client01.WaitForDisconnectOrFail(DefaultTimeout);
-
-                client01.WaitForConnectToFail(DefaultTimeout);
-            }
-        }
-
-        [TestMethod]
-        public async Task ClientCertChangeWithServerUpdateAcceptsReconnect()
-        {
-            using (var server = new ServerTestHarness())
-            using (var client01 = new ClientTestHarness())
-            {
-                server.InstallNewClientCert(client01.GetCurrentClientCert());
-                client01.InstallNewServerCert(server.GetCurrentServerCert());
-
-                await server.StartServer();
-
-                await client01.Connect();
-
-                client01.WaitForConnectOrFail(DefaultTimeout);
-
-                client01.HotSwapClientCert();
-                server.ForceDisconnectAsync(client01).Wait(DefaultTimeout);
-                client01.WaitForDisconnectOrFail(DefaultTimeout);
-
-                server.InstallNewClientCert(client01.GetCurrentClientCert());
-
-                client01.WaitForConnectOrFail(DefaultTimeout);
-            }
-        }
-
-        [TestMethod]
-        public async Task ServerCertChangeWithClientCertUpdateAllowsReconnect()
-        {
-            using (var server = new ServerTestHarness())
-            using (var client01 = new ClientTestHarness())
-            {
-                server.InstallNewClientCert(client01.GetCurrentClientCert());
-                client01.InstallNewServerCert(server.GetCurrentServerCert());
-
-                await server.StartServer();
-                await client01.Connect();
-
-                client01.WaitForConnectOrFail(DefaultTimeout);
-                server.HotSwapServerCert();
-
-                server.ForceDisconnectAsync(client01).Wait(DefaultTimeout);
-                client01.WaitForDisconnectOrFail(DefaultTimeout);
-                client01.InstallNewServerCert(server.GetCurrentServerCert());
-
-                client01.WaitForConnectOrFail(DefaultTimeout);
-            }
-        }
-
-        [TestMethod]
-        public async Task ServerCertChangeWithoutClientCertUpdateFailsReconnect()
-        {
-            using (var server = new ServerTestHarness())
-            using (var client01 = new ClientTestHarness())
-            {
-                server.InstallNewClientCert(client01.GetCurrentClientCert());
-                client01.InstallNewServerCert(server.GetCurrentServerCert());
-
-                await server.StartServer();
-                await client01.Connect();
-
-                client01.WaitForConnectOrFail(DefaultTimeout);
-                server.HotSwapServerCert();
-
-                server.ForceDisconnectAsync(client01).Wait(DefaultTimeout);
-                client01.WaitForDisconnectOrFail(DefaultTimeout);
-
-                client01.WaitForConnectToFail(DefaultTimeout);
-            }
-        }
-
-        static X509Certificate2 CreateSelfSignedCertificate(string oid)
-        {
-            var sanBuilder = new SubjectAlternativeNameBuilder();
-            sanBuilder.AddIpAddress(IPAddress.Loopback);
-            sanBuilder.AddIpAddress(IPAddress.IPv6Loopback);
-            sanBuilder.AddDnsName("localhost");
-
-            using (var rsa = RSA.Create())
-            {
-                var certRequest = new CertificateRequest("CN=localhost", rsa, HashAlgorithmName.SHA512, RSASignaturePadding.Pkcs1);
-
-                certRequest.CertificateExtensions.Add(
-                    new X509KeyUsageExtension(X509KeyUsageFlags.DataEncipherment | X509KeyUsageFlags.KeyEncipherment | X509KeyUsageFlags.DigitalSignature, false));
-
-                certRequest.CertificateExtensions.Add(new X509EnhancedKeyUsageExtension(new OidCollection { new Oid(oid) }, false));
-
-                certRequest.CertificateExtensions.Add(sanBuilder.Build());
-
-                using (var certificate = certRequest.CreateSelfSigned(DateTimeOffset.Now.AddMinutes(-10), DateTimeOffset.Now.AddMinutes(10)))
-                {
-                    var pfxCertificate = new X509Certificate2(
-                        certificate.Export(X509ContentType.Pfx),
-                        (string)null,
-                        X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.Exportable);
-
-                    return pfxCertificate;
-                }
-            }
-        }
-
-        sealed class ClientTestHarness : IDisposable
-        {
-            readonly HotSwappableClientCertProvider _hotSwapClient = new HotSwappableClientCertProvider();
-
-            IMqttClient _client;
-
-            public string ClientId => _client.Options.ClientId;
-
-            public Task Connect()
-            {
-                return Run_Client_Connection();
-            }
-
-            public void Dispose()
-            {
-                _client.Dispose();
-                _hotSwapClient.Dispose();
-            }
-
-            public X509Certificate2 GetCurrentClientCert()
-            {
-                var result = _hotSwapClient.GetCertificates()[0];
-                return new X509Certificate2(result);
-            }
-
-            public void HotSwapClientCert()
-            {
-                _hotSwapClient.HotSwapCert();
-            }
-
-            public void InstallNewServerCert(X509Certificate2 serverCert)
-            {
-                _hotSwapClient.InstallNewServerCert(serverCert);
-            }
-
-            public void WaitForConnectOrFail(TimeSpan timeout)
-            {
-                Thread.Sleep(100);
-
-                if (!_client.IsConnected)
-                {
-                    _client.ReconnectAsync().Wait(timeout);
-                }
-
-                WaitForConnect(timeout);
-
-                Assert.IsNotNull(_client, "Client was never initialized");
-                Assert.IsTrue(_client.IsConnected, $"Client connection failed after {timeout}");
-            }
-
-            public void WaitForConnectToFail(TimeSpan timeout)
-            {
-                Assert.IsFalse(_client.IsConnected, "Client should be disconnected before waiting for connect.");
-
-                WaitForConnect(timeout);
-
-                Assert.IsNotNull(_client, "Client was never initialized");
-                Assert.IsFalse(_client.IsConnected, "Client connection success but test wanted fail");
-            }
-
-            void WaitForDisconnect(TimeSpan timeout)
-            {
-                var timer = Stopwatch.StartNew();
-                while ((_client == null || _client.IsConnected) && timer.Elapsed < timeout)
-                {
-                    Thread.Sleep(100);
-                }
-            }
-
-            public void WaitForDisconnectOrFail(TimeSpan timeout)
-            {
-                WaitForDisconnect(timeout);
-
-                Assert.IsNotNull(_client, "Client was never initialized");
-                Assert.IsFalse(_client.IsConnected, $"Client connection should have disconnected after {timeout}");
-            }
-
-            async Task Run_Client_Connection()
-            {
-                var optionsBuilder = new MqttClientOptionsBuilder()
-                    .WithTlsOptions(
-                        o => o.WithClientCertificatesProvider(_hotSwapClient)
-                            .WithCertificateValidationHandler(_hotSwapClient.OnCertificateValidation)
-                            .WithSslProtocols(SslProtocols.Tls12))
-                    .WithTcpServer("localhost")
-                    .WithCleanSession()
-                    .WithProtocolVersion(MqttProtocolVersion.V500);
-
-                var mqttClientOptions = optionsBuilder.Build();
-
-                var factory = new MqttFactory();
-                var mqttClient = factory.CreateMqttClient();
-                _client = mqttClient;
-
-                await mqttClient.ConnectAsync(mqttClientOptions);
-            }
-
-            void WaitForConnect(TimeSpan timeout)
-            {
-                var timer = Stopwatch.StartNew();
-                while ((_client == null || !_client.IsConnected) && timer.Elapsed < timeout)
-                {
-                    Thread.Sleep(100);
-                }
-            }
-        }
-
-        sealed class ServerTestHarness : IDisposable
-        {
-            readonly HotSwappableServerCertProvider _hotSwapServer = new HotSwappableServerCertProvider();
-
-            MqttServer _server;
-
-            public void Dispose()
-            {
-                if (_server != null)
-                {
-                    _server.StopAsync().Wait();
-                    _server.Dispose();
-                }
-
-                _hotSwapServer?.Dispose();
-            }
-
-            public Task ForceDisconnectAsync(ClientTestHarness client)
-            {
-                return _server.DisconnectClientAsync(client.ClientId, MqttDisconnectReasonCode.UnspecifiedError);
-            }
-
-            public X509Certificate2 GetCurrentServerCert()
-            {
-                return _hotSwapServer.GetCertificate();
-            }
-
-            public void HotSwapServerCert()
-            {
-                _hotSwapServer.HotSwapCert();
-            }
-
-            public void InstallNewClientCert(X509Certificate2 serverCert)
-            {
-                _hotSwapServer.InstallNewClientCert(serverCert);
-            }
-
-            public Task StartServer()
-            {
-                var mqttFactory = new MqttFactory();
-
-                var mqttServerOptions = new MqttServerOptionsBuilder().WithEncryptionCertificate(_hotSwapServer)
-                    .WithRemoteCertificateValidationCallback(_hotSwapServer.RemoteCertificateValidationCallback)
-                    .WithEncryptedEndpoint()
-                    .Build();
-
-                mqttServerOptions.TlsEndpointOptions.ClientCertificateRequired = true;
-
-                _server = mqttFactory.CreateMqttServer(mqttServerOptions);
-                return _server.StartAsync();
-            }
-        }
-
-        class HotSwappableClientCertProvider : IMqttClientCertificatesProvider, IDisposable
-        {
-            X509Certificate2Collection _certificates;
-            ConcurrentBag<X509Certificate2> _serverCerts = new ConcurrentBag<X509Certificate2>();
-
-            public HotSwappableClientCertProvider()
-            {
-                _certificates = new X509Certificate2Collection(CreateSelfSignedCertificate("1.3.6.1.5.5.7.3.2"));
-            }
-            
-            public void Dispose()
-            {
-                if (_certificates != null)
-                {
-                    foreach (var certs in _certificates)
-                    {
-#if !NET452
-                        certs.Dispose();
-#endif
-                    }
-                }
-            }
-
-            public X509CertificateCollection GetCertificates()
-            {
-                return new X509Certificate2Collection(_certificates);
-            }
-
-            public void HotSwapCert()
-            {
-                _certificates = new X509Certificate2Collection(CreateSelfSignedCertificate("1.3.6.1.5.5.7.3.2"));
-            }
-
-            public void InstallNewServerCert(X509Certificate2 serverCert)
-            {
-                _serverCerts.Add(serverCert);
-            }
-
-            public bool OnCertificateValidation(MqttClientCertificateValidationEventArgs certContext)
-            {
-                var serverCerts = _serverCerts.ToArray();
-
-                var providedCert = certContext.Certificate.GetRawCertData();
-                for (int i = 0, n = serverCerts.Length; i < n; i++)
-                {
-                    var currentcert = serverCerts[i];
-
-                    if (currentcert.RawData.SequenceEqual(providedCert))
-                    {
-                        return true;
-                    }
-                }
-
-                return false;
-            }
-        }
-
-        sealed class HotSwappableServerCertProvider : ICertificateProvider, IDisposable
-        {
-            readonly ConcurrentBag<X509Certificate2> _clientCerts = new ConcurrentBag<X509Certificate2>();
-            X509Certificate2 _certificate;
-
-            public HotSwappableServerCertProvider()
-            {
-                _certificate = CreateSelfSignedCertificate("1.3.6.1.5.5.7.3.1");
-            }
-
-            public void Dispose()
-            {
-#if !NET452
-                _certificate.Dispose();
-#endif
-            }
-
-            public X509Certificate2 GetCertificate()
-            {
-                return _certificate;
-            }
-
-            public void HotSwapCert()
-            {
-                var newCert = CreateSelfSignedCertificate("1.3.6.1.5.5.7.3.1");
-                var oldCert = Interlocked.Exchange(ref _certificate, newCert);
-#if !NET452
-                oldCert.Dispose();
-#endif
-            }
-
-            public void InstallNewClientCert(X509Certificate2 certificate)
-            {
-                _clientCerts.Add(certificate);
-            }
-
-            public bool RemoteCertificateValidationCallback(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
-            {
-                var serverCerts = _clientCerts.ToArray();
-
-                var providedCert = certificate.GetRawCertData();
-                for (int i = 0, n = serverCerts.Length; i < n; i++)
-                {
-                    var currentCert = serverCerts[i];
-
-                    if (currentCert.RawData.SequenceEqual(providedCert))
-                    {
-                        return true;
-                    }
-                }
-
-                return false;
-            }
-        }
-    }
-}
-
-#endif

Source/MQTTnet.Tests/Server/Publishing_Tests.cs

@@ -8,7 +8,6 @@ using MQTTnet.Client;
 using MQTTnet.Formatter;
 using MQTTnet.Internal;
 using MQTTnet.Protocol;
-using MQTTnet.Server;
 
 namespace MQTTnet.Tests.Server
 {

Source/MQTTnet.Tests/Server/Session_Tests.cs

@@ -283,7 +283,7 @@ namespace MQTTnet.Tests.Server
 
                 server.InterceptingPublishAsync += e =>
                 {
-                    e.ApplicationMessage.PayloadSegment = new ArraySegment<byte>(Encoding.UTF8.GetBytes(e.SessionItems["default_payload"] as string ?? string.Empty));
+                    e.ApplicationMessage.Payload = Encoding.UTF8.GetBytes(e.SessionItems["default_payload"] as string ?? string.Empty);
                     return CompletedTask.Instance;
                 };
 

Source/MQTTnet.Tests/Server/Tls_Tests.cs

@@ -101,7 +101,7 @@ namespace MQTTnet.Tests.Server
                 new MqttApplicationMessage
                 {
                     Topic = "TestTopic1",
-                    PayloadSegment = new ArraySegment<byte>(new byte[] { 1, 2, 3, 4 })
+                    Payload = new byte[] { 1, 2, 3, 4 }
                 });
 
             await testEnvironment.Server.InjectApplicationMessage(
@@ -109,7 +109,7 @@ namespace MQTTnet.Tests.Server
                     new MqttApplicationMessage
                     {
                         Topic = "TestTopic1",
-                        PayloadSegment = new ArraySegment<byte>(new byte[] { 1, 2, 3, 4 })
+                        Payload = new byte[] { 1, 2, 3, 4 }
                     }));
 
             certificateProvider.CurrentCertificate = CreateCertificate(secondOid);
@@ -137,7 +137,7 @@ namespace MQTTnet.Tests.Server
                 new MqttApplicationMessage
                 {
                     Topic = "TestTopic2",
-                    PayloadSegment = new ArraySegment<byte>(new byte[] { 1, 2, 3, 4 })
+                    Payload = new byte[] { 1, 2, 3, 4 }
                 });
 
             await testEnvironment.Server.InjectApplicationMessage(
@@ -145,7 +145,7 @@ namespace MQTTnet.Tests.Server
                     new MqttApplicationMessage
                     {
                         Topic = "TestTopic2",
-                        PayloadSegment = new ArraySegment<byte>(new byte[] { 1, 2, 3, 4 })
+                        Payload = new byte[] { 1, 2, 3, 4 }
                     }));
 
             // Ensure first client still works
@@ -153,7 +153,7 @@ namespace MQTTnet.Tests.Server
                 new MqttApplicationMessage
                 {
                     Topic = "TestTopic1",
-                    PayloadSegment = new ArraySegment<byte>(new byte[] { 1, 2, 3, 4 })
+                    Payload = new byte[] { 1, 2, 3, 4 }
                 });
 
             await testEnvironment.Server.InjectApplicationMessage(
@@ -161,7 +161,7 @@ namespace MQTTnet.Tests.Server
                     new MqttApplicationMessage
                     {
                         Topic = "TestTopic1",
-                        PayloadSegment = new ArraySegment<byte>(new byte[] { 1, 2, 3, 4 })
+                        Payload = new byte[] { 1, 2, 3, 4 }
                     }));
 
             await Task.Delay(1000);
@@ -178,10 +178,12 @@ namespace MQTTnet.Tests.Server
             var clientOptionsBuilder = testEnvironment.Factory.CreateClientOptionsBuilder();
             clientOptionsBuilder.WithClientId(Guid.NewGuid().ToString())
                 .WithTcpServer("localhost", 8883)
-                .WithTlsOptions(
-                    o =>
+                .WithTls(
+                    tls =>
                     {
-                        o.WithSslProtocols(SslProtocols.Tls12).WithCertificateValidationHandler(certValidator);
+                        tls.UseTls = true;
+                        tls.SslProtocol = SslProtocols.Tls12;
+                        tls.CertificateValidationHandler = certValidator;
                     });
 
             var clientOptions = clientOptionsBuilder.Build();

Source/MQTTnet.Tests/TopicGenerator.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using MQTTnet.Extensions.TopicTemplate;
 
 namespace MQTTnet.Tests
 {
@@ -32,43 +31,31 @@ namespace MQTTnet.Tests
             {
                 maxNumLevel3Topics = 1;
             }
-            
-            MqttTopicTemplate baseTemplate = new MqttTopicTemplate("{publisher}/{building}/{level}/{sensor}");
 
             for (var p = 0; p < numPublishers; ++p)
             {
                 int publisherTopicCount = 0;
                 var publisherName = "pub" + p;
-                var publisherTemplate = baseTemplate
-                    .WithParameter("publisher", publisherName);
-                
                 for (var l1 = 0; l1 < numLevel1Topics; ++l1)
                 {
-                    var l1Template = publisherTemplate.WithParameter("building", "building" + (l1 + 1));
                     for (var l2 = 0; l2 < numLevel2Topics; ++l2)
                     {
-                        var l2Template = l1Template.WithParameter("level", "level" + (l2 + 1));
                         for (var l3 = 0; l3 < maxNumLevel3Topics; ++l3)
                         {
                             if (publisherTopicCount >= numTopicsPerPublisher)
                                 break;
 
-                            var l3Template = l2Template
-                                .WithParameter("sensor", "sensor" + (l3 + 1));
-                            AddPublisherTopic(publisherName, l3Template.TopicFilter, topicsByPublisher);
+                            var topic = string.Format("{0}/building{1}/level{2}/sensor{3}", publisherName, l1 + 1, l2 + 1, l3 + 1);
+                            AddPublisherTopic(publisherName, topic, topicsByPublisher);
 
                             if (l2 == 0)
                             {
-                                var singleWildcardTopic = l1Template
-                                    .WithParameter("sensor", "sensor" + (l3 + 1))
-                                    .TopicFilter;
+                                var singleWildcardTopic = string.Format("{0}/building{1}/+/sensor{2}", publisherName, l1 + 1, l3 + 1);
                                 AddPublisherTopic(publisherName, singleWildcardTopic, singleWildcardTopicsByPublisher);
                             }
                             if ((l1 == 0) && (l3 == 0))
                             {
-                                var multiWildcardTopic = publisherTemplate
-                                    .WithParameter("level", "level" + (l2 + 1))
-                                    .TopicFilter;
+                                var multiWildcardTopic = string.Format("{0}/+/level{1}/+", publisherName, l2 + 1);
                                 AddPublisherTopic(publisherName, multiWildcardTopic, multiWildcardTopicsByPublisher);
                             }
 

Source/MQTTnet/Adapter/IMqttChannelAdapter.cs

@@ -25,6 +25,8 @@ namespace MQTTnet.Adapter
 
         long BytesReceived { get; }
 
+        bool IsReadingPacket { get; }
+
         Task ConnectAsync(CancellationToken cancellationToken);
 
         Task DisconnectAsync(CancellationToken cancellationToken);

Source/MQTTnet/Adapter/IMqttServerAdapter.cs

@@ -14,7 +14,6 @@ namespace MQTTnet.Adapter
         Func<IMqttChannelAdapter, Task> ClientHandler { get; set; }
 
         Task StartAsync(MqttServerOptions options, IMqttNetLogger logger);
-
         Task StopAsync();
     }
 }

Source/MQTTnet/Adapter/MqttChannelAdapter.cs

@@ -26,7 +26,9 @@ namespace MQTTnet.Adapter
         readonly IMqttChannel _channel;
         readonly byte[] _fixedHeaderBuffer = new byte[2];
         readonly MqttNetSourceLogger _logger;
+
         readonly byte[] _singleByteBuffer = new byte[1];
+
         readonly AsyncLock _syncRoot = new AsyncLock();
 
         Statistics _statistics; // mutable struct, don't make readonly!
@@ -45,8 +47,6 @@ namespace MQTTnet.Adapter
             _logger = logger.WithSource(nameof(MqttChannelAdapter));
         }
 
-        public bool AllowPacketFragmentation { get; set; } = true;
-
         public long BytesReceived => Volatile.Read(ref _statistics._bytesReceived);
 
         public long BytesSent => Volatile.Read(ref _statistics._bytesSent);
@@ -55,12 +55,16 @@ namespace MQTTnet.Adapter
 
         public string Endpoint => _channel.Endpoint;
 
+        public bool IsReadingPacket { get; private set; }
+
         public bool IsSecureConnection => _channel.IsSecureConnection;
 
         public MqttPacketFormatterAdapter PacketFormatterAdapter { get; }
 
         public MqttPacketInspector PacketInspector { get; set; }
 
+        public bool AllowPacketFragmentation { get; set; } = true;
+
         public async Task ConnectAsync(CancellationToken cancellationToken)
         {
             cancellationToken.ThrowIfCancellationRequested();
@@ -74,30 +78,12 @@ namespace MQTTnet.Adapter
                  * block forever. Even a cancellation token is not supported properly.
                  */
 
+                var connectTask = _channel.ConnectAsync(cancellationToken);
+
                 var timeout = new TaskCompletionSource<object>();
                 using (cancellationToken.Register(() => timeout.TrySetResult(null)))
                 {
-                    var connectTask = Task.Run(
-                        async () =>
-                        {
-                            try
-                            {
-                                await _channel.ConnectAsync(cancellationToken).ConfigureAwait(false);
-                            }
-                            catch
-                            {
-                                // If the timeout is already reached the exception is no longer of interest and
-                                // must be catched. Otherwise it will arrive at the TaskScheduler.UnobservedTaskException.
-                                if (!timeout.Task.IsCompleted)
-                                {
-                                    throw;
-                                }
-                            }
-                        },
-                        CancellationToken.None);
-
                     await Task.WhenAny(connectTask, timeout.Task).ConfigureAwait(false);
-
                     if (timeout.Task.IsCompleted && !connectTask.IsCompleted)
                     {
                         throw new OperationCanceledException("MQTT connect canceled.", cancellationToken);
@@ -141,8 +127,7 @@ namespace MQTTnet.Adapter
 
             try
             {
-                var localPacketInspector = PacketInspector;
-                localPacketInspector?.BeginReceivePacket();
+                PacketInspector?.BeginReceivePacket();
 
                 ReceivedMqttPacket receivedPacket;
                 var receivedPacketTask = ReceiveAsync(cancellationToken);
@@ -160,10 +145,7 @@ namespace MQTTnet.Adapter
                     return null;
                 }
 
-                if (localPacketInspector != null)
-                {
-                    await localPacketInspector.EndReceivePacket().ConfigureAwait(false);
-                }
+                PacketInspector?.EndReceivePacket();
 
                 Interlocked.Add(ref _statistics._bytesSent, receivedPacket.TotalLength);
 
@@ -219,15 +201,10 @@ namespace MQTTnet.Adapter
                 try
                 {
                     var packetBuffer = PacketFormatterAdapter.Encode(packet);
+                    PacketInspector?.BeginSendPacket(packetBuffer);
 
-                    var localPacketInspector = PacketInspector;
-                    if (localPacketInspector != null)
-                    {
-                        await localPacketInspector.BeginSendPacket(packetBuffer).ConfigureAwait(false);    
-                    }
-                    
                     _logger.Verbose("TX ({0} bytes) >>> {1}", packetBuffer.Length, packet);
-
+                    
                     if (packetBuffer.Payload.Count == 0 || !AllowPacketFragmentation)
                     {
                         await _channel.WriteAsync(packetBuffer.Join(), true, cancellationToken).ConfigureAwait(false);
@@ -396,45 +373,53 @@ namespace MQTTnet.Adapter
                 return ReceivedMqttPacket.Empty;
             }
 
-            var fixedHeader = readFixedHeaderResult.FixedHeader;
-            if (fixedHeader.RemainingLength == 0)
+            IsReadingPacket = true;
+            try
             {
-                return new ReceivedMqttPacket(fixedHeader.Flags, EmptyBuffer.ArraySegment, 2);
+                var fixedHeader = readFixedHeaderResult.FixedHeader;
+                if (fixedHeader.RemainingLength == 0)
+                {
+                    return new ReceivedMqttPacket(fixedHeader.Flags, EmptyBuffer.ArraySegment, 2);
+                }
+
+                var bodyLength = fixedHeader.RemainingLength;
+                var body = new byte[bodyLength];
+
+                var bodyOffset = 0;
+                var chunkSize = Math.Min(ReadBufferSize, bodyLength);
+
+                do
+                {
+                    var bytesLeft = body.Length - bodyOffset;
+                    if (chunkSize > bytesLeft)
+                    {
+                        chunkSize = bytesLeft;
+                    }
+
+                    var readBytes = await _channel.ReadAsync(body, bodyOffset, chunkSize, cancellationToken).ConfigureAwait(false);
+
+                    if (cancellationToken.IsCancellationRequested)
+                    {
+                        return ReceivedMqttPacket.Empty;
+                    }
+
+                    if (readBytes == 0)
+                    {
+                        return ReceivedMqttPacket.Empty;
+                    }
+
+                    bodyOffset += readBytes;
+                } while (bodyOffset < bodyLength);
+
+                PacketInspector?.FillReceiveBuffer(body);
+
+                var bodySegment = new ArraySegment<byte>(body, 0, bodyLength);
+                return new ReceivedMqttPacket(fixedHeader.Flags, bodySegment, fixedHeader.TotalLength);
             }
-
-            var bodyLength = fixedHeader.RemainingLength;
-            var body = new byte[bodyLength];
-
-            var bodyOffset = 0;
-            var chunkSize = Math.Min(ReadBufferSize, bodyLength);
-
-            do
+            finally
             {
-                var bytesLeft = body.Length - bodyOffset;
-                if (chunkSize > bytesLeft)
-                {
-                    chunkSize = bytesLeft;
-                }
-
-                var readBytes = await _channel.ReadAsync(body, bodyOffset, chunkSize, cancellationToken).ConfigureAwait(false);
-
-                if (cancellationToken.IsCancellationRequested)
-                {
-                    return ReceivedMqttPacket.Empty;
-                }
-
-                if (readBytes == 0)
-                {
-                    return ReceivedMqttPacket.Empty;
-                }
-
-                bodyOffset += readBytes;
-            } while (bodyOffset < bodyLength);
-
-            PacketInspector?.FillReceiveBuffer(body);
-
-            var bodySegment = new ArraySegment<byte>(body, 0, bodyLength);
-            return new ReceivedMqttPacket(fixedHeader.Flags, bodySegment, fixedHeader.TotalLength);
+                IsReadingPacket = false;
+            }
         }
 
         static bool WrapAndThrowException(Exception exception)

Source/MQTTnet/Adapter/MqttPacketInspector.cs

@@ -4,7 +4,6 @@
 
 using System;
 using System.IO;
-using System.Threading.Tasks;
 using MQTTnet.Diagnostics;
 using MQTTnet.Formatter;
 using MQTTnet.Internal;
@@ -13,20 +12,16 @@ namespace MQTTnet.Adapter
 {
     public sealed class MqttPacketInspector
     {
-        readonly AsyncEvent<InspectMqttPacketEventArgs> _asyncEvent;
         readonly MqttNetSourceLogger _logger;
-
+        readonly AsyncEvent<InspectMqttPacketEventArgs> _asyncEvent;
+        
         MemoryStream _receivedPacketBuffer;
-
+        
         public MqttPacketInspector(AsyncEvent<InspectMqttPacketEventArgs> asyncEvent, IMqttNetLogger logger)
         {
             _asyncEvent = asyncEvent ?? throw new ArgumentNullException(nameof(asyncEvent));
-
-            if (logger == null)
-            {
-                throw new ArgumentNullException(nameof(logger));
-            }
-
+            
+            if (logger == null) throw new ArgumentNullException(nameof(logger));
             _logger = logger.WithSource(nameof(MqttPacketInspector));
         }
 
@@ -41,15 +36,28 @@ namespace MQTTnet.Adapter
             {
                 _receivedPacketBuffer = new MemoryStream();
             }
-
+            
             _receivedPacketBuffer?.SetLength(0);
         }
 
-        public Task BeginSendPacket(MqttPacketBuffer buffer)
+        public void EndReceivePacket()
         {
             if (!_asyncEvent.HasHandlers)
             {
-                return CompletedTask.Instance;
+                return;
+            }
+
+            var buffer = _receivedPacketBuffer.ToArray();
+            _receivedPacketBuffer.SetLength(0);
+
+            InspectPacket(buffer, MqttPacketFlowDirection.Inbound);
+        }
+
+        public void BeginSendPacket(MqttPacketBuffer buffer)
+        {
+            if (!_asyncEvent.HasHandlers)
+            {
+                return;
             }
 
             // Create a copy of the actual packet so that the inspector gets no access
@@ -57,20 +65,7 @@ namespace MQTTnet.Adapter
             // intended for debugging etc. so that this is OK.
             var bufferCopy = buffer.ToArray();
 
-            return InspectPacket(bufferCopy, MqttPacketFlowDirection.Outbound);
-        }
-
-        public Task EndReceivePacket()
-        {
-            if (!_asyncEvent.HasHandlers)
-            {
-                return CompletedTask.Instance;
-            }
-
-            var buffer = _receivedPacketBuffer.ToArray();
-            _receivedPacketBuffer.SetLength(0);
-
-            return InspectPacket(buffer, MqttPacketFlowDirection.Inbound);
+            InspectPacket(bufferCopy, MqttPacketFlowDirection.Outbound);
         }
 
         public void FillReceiveBuffer(byte[] buffer)
@@ -79,16 +74,16 @@ namespace MQTTnet.Adapter
             {
                 return;
             }
-
+            
             _receivedPacketBuffer?.Write(buffer, 0, buffer.Length);
         }
 
-        async Task InspectPacket(byte[] buffer, MqttPacketFlowDirection direction)
+        void InspectPacket(byte[] buffer, MqttPacketFlowDirection direction)
         {
             try
             {
                 var eventArgs = new InspectMqttPacketEventArgs(direction, buffer);
-                await _asyncEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
+                _asyncEvent.InvokeAsync(eventArgs).GetAwaiter().GetResult();
             }
             catch (Exception exception)
             {

Source/MQTTnet/Client/Exceptions/MqttClientUnexpectedDisconnectReceivedException.cs

@@ -2,7 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using System.Collections.Generic;
 using MQTTnet.Exceptions;
 using MQTTnet.Packets;
@@ -12,9 +11,8 @@ namespace MQTTnet.Client
 {
     public sealed class MqttClientUnexpectedDisconnectReceivedException : MqttCommunicationException
     {
-        public MqttClientUnexpectedDisconnectReceivedException(MqttDisconnectPacket disconnectPacket, Exception innerExcpetion = null) : base(
-            $"Unexpected DISCONNECT (Reason code={disconnectPacket.ReasonCode}) received.",
-            innerExcpetion)
+        public MqttClientUnexpectedDisconnectReceivedException(MqttDisconnectPacket disconnectPacket) 
+            : base($"Unexpected DISCONNECT (Reason code={disconnectPacket.ReasonCode}) received.")
         {
             ReasonCode = disconnectPacket.ReasonCode;
             SessionExpiryInterval = disconnectPacket.SessionExpiryInterval;
@@ -25,12 +23,12 @@ namespace MQTTnet.Client
 
         public MqttDisconnectReasonCode? ReasonCode { get; }
 
-        public string ReasonString { get; }
-
-        public string ServerReference { get; }
-
         public uint? SessionExpiryInterval { get; }
 
+        public string ReasonString { get; }
+
         public List<MqttUserProperty> UserProperties { get; }
+
+        public string ServerReference { get; }
     }
-}
+}

Source/MQTTnet/Client/ExtendedAuthenticationExchange/MqttExtendedAuthenticationExchangeContext.cs

@@ -4,7 +4,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Threading;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
 
@@ -12,7 +11,7 @@ namespace MQTTnet.Client
 {
     public class MqttExtendedAuthenticationExchangeContext
     {
-        public MqttExtendedAuthenticationExchangeContext(MqttAuthPacket authPacket, MqttClient client, CancellationToken cancellationToken)
+        public MqttExtendedAuthenticationExchangeContext(MqttAuthPacket authPacket, MqttClient client)
         {
             if (authPacket == null) throw new ArgumentNullException(nameof(authPacket));
 
@@ -23,7 +22,6 @@ namespace MQTTnet.Client
             UserProperties = authPacket.UserProperties;
 
             Client = client ?? throw new ArgumentNullException(nameof(client));
-            CancellationToken = cancellationToken;
         }
 
         /// <summary>
@@ -60,10 +58,5 @@ namespace MQTTnet.Client
         public List<MqttUserProperty> UserProperties { get; }
 
         public MqttClient Client { get; }
-
-        /// <summary>
-        /// The cancellation token passed to the operation being authenticated (e.g. ConnectAsync).
-        /// </summary>
-        public CancellationToken CancellationToken { get; }
     }
 }

Source/MQTTnet/Client/MqttClient.cs

@@ -48,7 +48,6 @@ namespace MQTTnet.Client
         Task _packetReceiverTask;
         AsyncQueue<MqttPublishPacket> _publishPacketReceiverQueue;
         Task _publishPacketReceiverTask;
-        MqttDisconnectPacket _unexpectedDisconnectPacket;
 
         public MqttClient(IMqttClientAdapterFactory channelFactory, IMqttNetLogger logger)
         {
@@ -89,8 +88,6 @@ namespace MQTTnet.Client
 
         public bool IsConnected => (MqttClientConnectionStatus)_connectionStatus == MqttClientConnectionStatus.Connected;
 
-        bool IsConnecting => (MqttClientConnectionStatus)_connectionStatus == MqttClientConnectionStatus.Connecting;
-
         public MqttClientOptions Options { get; private set; }
 
         public async Task<MqttClientConnectResult> ConnectAsync(MqttClientOptions options, CancellationToken cancellationToken = default)
@@ -126,8 +123,6 @@ namespace MQTTnet.Client
                 var adapter = _adapterFactory.CreateClientAdapter(options, new MqttPacketInspector(_events.InspectPacketEvent, _rootLogger), _rootLogger);
                 _adapter = adapter ?? throw new InvalidOperationException("The adapter factory did not provide an adapter.");
 
-                _unexpectedDisconnectPacket = null;
-
                 if (cancellationToken.CanBeCanceled)
                 {
                     connectResult = await ConnectInternal(adapter, cancellationToken).ConfigureAwait(false);
@@ -145,7 +140,6 @@ namespace MQTTnet.Client
                 if (connectResult.ResultCode != MqttClientConnectResultCode.Success)
                 {
                     _logger.Warning("Connecting failed: {0}", connectResult.ResultCode);
-                    await DisconnectInternal(null, null, connectResult).ConfigureAwait(false);
                     return connectResult;
                 }
 
@@ -220,7 +214,7 @@ namespace MQTTnet.Client
                 }
 
                 // Sending the DISCONNECT may fail due to connection issues. The resulting exception
-                // must be thrown to let the caller know that the disconnect was not clean.
+                // must be throw to let the caller know that the disconnect is not a clean one.
                 var disconnectPacket = MqttPacketFactories.Disconnect.Create(options);
 
                 if (cancellationToken.CanBeCanceled)
@@ -243,11 +237,6 @@ namespace MQTTnet.Client
 
         public async Task PingAsync(CancellationToken cancellationToken = default)
         {
-            cancellationToken.ThrowIfCancellationRequested();
-
-            ThrowIfDisposed();
-            ThrowIfNotConnected();
-
             if (cancellationToken.CanBeCanceled)
             {
                 await Request<MqttPingRespPacket>(MqttPingReqPacket.Instance, cancellationToken).ConfigureAwait(false);
@@ -306,7 +295,7 @@ namespace MQTTnet.Client
             }
 
             ThrowIfDisposed();
-            ThrowIfNotConnectedOrConnecting();
+            ThrowIfNotConnected();
 
             var authPacket = new MqttAuthPacket
             {
@@ -314,7 +303,6 @@ namespace MQTTnet.Client
                 AuthenticationMethod = Options.AuthenticationMethod,
                 AuthenticationData = data.AuthenticationData,
                 ReasonString = data.ReasonString,
-                ReasonCode = data.ReasonCode,
                 UserProperties = data.UserProperties
             };
 
@@ -333,14 +321,14 @@ namespace MQTTnet.Client
                 MqttTopicValidator.ThrowIfInvalidSubscribe(topicFilter.Topic);
             }
 
-            ThrowIfDisposed();
-            ThrowIfNotConnected();
-
             if (Options.ValidateFeatures)
             {
                 MqttClientSubscribeOptionsValidator.ThrowIfNotSupported(options, _adapter.PacketFormatterAdapter.ProtocolVersion);
             }
 
+            ThrowIfDisposed();
+            ThrowIfNotConnected();
+
             var subscribePacket = MqttPacketFactories.Subscribe.Create(options);
             subscribePacket.PacketIdentifier = _packetIdentifierProvider.GetNextPacketIdentifier();
 
@@ -411,38 +399,30 @@ namespace MQTTnet.Client
 
         Task AcknowledgeReceivedPublishPacket(MqttApplicationMessageReceivedEventArgs eventArgs, CancellationToken cancellationToken)
         {
-            switch (eventArgs.PublishPacket.QualityOfServiceLevel)
+            if (eventArgs.PublishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtMostOnce)
             {
-                case MqttQualityOfServiceLevel.AtMostOnce:
+                // no response required
+            }
+            else if (eventArgs.PublishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtLeastOnce)
+            {
+                if (!eventArgs.ProcessingFailed)
                 {
-                    // no response required
-                    break;
+                    var pubAckPacket = MqttPacketFactories.PubAck.Create(eventArgs);
+                    return Send(pubAckPacket, cancellationToken);
                 }
-                case MqttQualityOfServiceLevel.AtLeastOnce:
+            }
+            else if (eventArgs.PublishPacket.QualityOfServiceLevel == MqttQualityOfServiceLevel.ExactlyOnce)
+            {
+                if (!eventArgs.ProcessingFailed)
                 {
-                    if (!eventArgs.ProcessingFailed)
-                    {
-                        var pubAckPacket = MqttPacketFactories.PubAck.Create(eventArgs);
-                        return Send(pubAckPacket, cancellationToken);
-                    }
-
-                    break;
-                }
-                case MqttQualityOfServiceLevel.ExactlyOnce:
-                {
-                    if (!eventArgs.ProcessingFailed)
-                    {
-                        var pubRecPacket = MqttPacketFactories.PubRec.Create(eventArgs);
-                        return Send(pubRecPacket, cancellationToken);
-                    }
-
-                    break;
-                }
-                default:
-                {
-                    throw new MqttProtocolViolationException("Received a not supported QoS level.");
+                    var pubRecPacket = MqttPacketFactories.PubRec.Create(eventArgs);
+                    return Send(pubRecPacket, cancellationToken);
                 }
             }
+            else
+            {
+                throw new MqttProtocolViolationException("Received a not supported QoS level.");
+            }
 
             return CompletedTask.Instance;
         }
@@ -456,31 +436,24 @@ namespace MQTTnet.Client
                 var connectPacket = MqttPacketFactories.Connect.Create(options);
                 await Send(connectPacket, cancellationToken).ConfigureAwait(false);
 
-                for (; ; )
+                var receivedPacket = await Receive(cancellationToken).ConfigureAwait(false);
+
+                if (receivedPacket is MqttConnAckPacket connAckPacket)
+                {
+                    result = MqttClientResultFactory.ConnectResult.Create(connAckPacket, _adapter.PacketFormatterAdapter.ProtocolVersion);
+                }
+                else if (receivedPacket is MqttAuthPacket)
+                {
+                    throw new NotSupportedException("Extended authentication handler is not yet supported");
+                }
+                else if (receivedPacket == null)
                 {
-                    cancellationToken.ThrowIfCancellationRequested();
-
-                    var receivedPacket = await Receive(cancellationToken).ConfigureAwait(false);
-
-                    if (receivedPacket is MqttAuthPacket authPacket)
-                    {
-                        await ProcessReceivedAuthPacket(authPacket, cancellationToken).ConfigureAwait(false);
-                        continue;
-                    }
-
-                    if (receivedPacket is MqttConnAckPacket connAckPacket)
-                    {
-                        result = MqttClientResultFactory.ConnectResult.Create(connAckPacket, channelAdapter.PacketFormatterAdapter.ProtocolVersion);
-                        break;
-                    }
-
-                    if (receivedPacket != null)
-                    {
-                        throw new MqttProtocolViolationException($"Received other packet than CONNACK or AUTH while connecting ({receivedPacket}).");
-                    }
-
                     throw new MqttCommunicationException("Connection closed.");
                 }
+                else
+                {
+                    throw new InvalidOperationException($"Received an unexpected MQTT packet ({receivedPacket}).");
+                }
             }
             catch (Exception exception)
             {
@@ -492,10 +465,11 @@ namespace MQTTnet.Client
             // did send a proper ACK packet with a non success response.
             if (options.ThrowOnNonSuccessfulConnectResponse)
             {
+                _logger.Warning(
+                    "Client will now throw an _MqttConnectingFailedException_. This is obsolete and will be removed in the future. Consider setting _ThrowOnNonSuccessfulResponseFromServer=False_ in client options.");
+
                 if (result.ResultCode != MqttClientConnectResultCode.Success)
                 {
-                    _logger.Warning(
-                        "Client will now throw an _MqttConnectingFailedException_. This is obsolete and will be removed in the future. Consider setting _ThrowOnNonSuccessfulResponseFromServer=False_ in client options.");
                     throw new MqttConnectingFailedException($"Connecting with MQTT server failed ({result.ResultCode}).", null, result);
                 }
             }
@@ -539,7 +513,7 @@ namespace MQTTnet.Client
             using (var effectiveCancellationToken = CancellationTokenSource.CreateLinkedTokenSource(backgroundCancellationToken, cancellationToken))
             {
                 _logger.Verbose("Trying to connect with server '{0}'", Options.ChannelOptions);
-                await channelAdapter.ConnectAsync(effectiveCancellationToken.Token).ConfigureAwait(false);
+                await _adapter.ConnectAsync(effectiveCancellationToken.Token).ConfigureAwait(false);
                 _logger.Verbose("Connection with server established");
 
                 _publishPacketReceiverQueue?.Dispose();
@@ -609,8 +583,8 @@ namespace MQTTnet.Client
                     _disconnectUserProperties,
                     exception);
 
-                // This handler must be executed in a new thread to prevent a deadlock
-                // that may occur when attempting to reconnect within that handler, etc.
+                // 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(() => _events.DisconnectedEvent.InvokeAsync(eventArgs)).RunInBackground(_logger);
             }
         }
@@ -619,9 +593,12 @@ namespace MQTTnet.Client
         {
             var clientWasConnected = IsConnected;
 
-            return !DisconnectIsPendingOrFinished() ?
-                DisconnectCore(sender, exception, connectResult, clientWasConnected)
-                : CompletedTask.Instance;
+            if (!DisconnectIsPendingOrFinished())
+            {
+                return DisconnectCore(sender, exception, connectResult, clientWasConnected);
+            }
+
+            return CompletedTask.Instance;
         }
 
         bool DisconnectIsPendingOrFinished()
@@ -674,46 +651,24 @@ namespace MQTTnet.Client
 
         Task OnConnected(MqttClientConnectResult connectResult)
         {
-            if (!_events.ConnectedEvent.HasHandlers)
+            if (_events.ConnectedEvent.HasHandlers)
             {
-                return CompletedTask.Instance;
+                var eventArgs = new MqttClientConnectedEventArgs(connectResult);
+                return _events.ConnectedEvent.InvokeAsync(eventArgs);
             }
 
-            var eventArgs = new MqttClientConnectedEventArgs(connectResult);
-            return _events.ConnectedEvent.InvokeAsync(eventArgs);
+            return CompletedTask.Instance;
         }
 
-        Task ProcessReceivedAuthPacket(MqttAuthPacket authPacket, CancellationToken cancellationToken)
+        Task ProcessReceivedAuthPacket(MqttAuthPacket authPacket)
         {
             var extendedAuthenticationExchangeHandler = Options.ExtendedAuthenticationExchangeHandler;
-            if (extendedAuthenticationExchangeHandler == null)
+            if (extendedAuthenticationExchangeHandler != null)
             {
-                // From RFC:
-                // The Client can close the connection at any point in this process. It MAY send a DISCONNECT packet before doing so.
-                // The Server can reject the authentication at any point in this process. It MAY send a CONNACK with a Reason Code of
-                // 0x80 or above as described in section 4.13, and MUST close the Network Connection [MQTT-4.12.0-4].
-                //
-                // If the re-authentication fails, the Client or Server SHOULD send DISCONNECT with an appropriate Reason Code
-                // as described in section 4.13, and MUST close the Network Connection [MQTT-4.12.1-2].
-                //
-                // Since we have no handler there is no chance to fulfil the initial authentication or re-authentication requests.
-
-                if (IsConnecting)
-                {
-                    throw new MqttCommunicationException("No handler was provided to handle the extended authentication exchange.");
-                }
-
-                _ = DisconnectAsync(new MqttClientDisconnectOptions
-                {
-                    Reason = MqttClientDisconnectOptionsReason.ImplementationSpecificError,
-                    ReasonString = "Unable to handle AUTH packet"
-                },
-                cancellationToken);
-
-                return CompletedTask.Instance;
+                return extendedAuthenticationExchangeHandler.HandleRequestAsync(new MqttExtendedAuthenticationExchangeContext(authPacket, this));
             }
 
-            return extendedAuthenticationExchangeHandler.HandleRequestAsync(new MqttExtendedAuthenticationExchangeContext(authPacket, this, cancellationToken));
+            return CompletedTask.Instance;
         }
 
         Task ProcessReceivedDisconnectPacket(MqttDisconnectPacket disconnectPacket)
@@ -721,10 +676,9 @@ namespace MQTTnet.Client
             _disconnectReason = (int)disconnectPacket.ReasonCode;
             _disconnectReasonString = disconnectPacket.ReasonString;
             _disconnectUserProperties = disconnectPacket.UserProperties;
-            _unexpectedDisconnectPacket = disconnectPacket;
 
             // Also dispatch disconnect to waiting threads to generate a proper exception.
-            _packetDispatcher.Dispose(new MqttClientUnexpectedDisconnectReceivedException(disconnectPacket, null));
+            _packetDispatcher.Dispose(new MqttClientUnexpectedDisconnectReceivedException(disconnectPacket));
 
             return DisconnectInternal(_packetReceiverTask, null, null);
         }
@@ -749,30 +703,27 @@ namespace MQTTnet.Client
                         await eventArgs.AcknowledgeAsync(cancellationToken).ConfigureAwait(false);
                     }
                 }
-                catch (ObjectDisposedException)
-                {
-                }
                 catch (OperationCanceledException)
                 {
                 }
                 catch (Exception exception)
                 {
-                    _logger.Error(exception, "Error while handling application message");
+                    _logger.Error(exception, "Error while handling application message.");
                 }
             }
         }
 
         Task ProcessReceivedPubRecPacket(MqttPubRecPacket pubRecPacket, CancellationToken cancellationToken)
         {
-            if (_packetDispatcher.TryDispatch(pubRecPacket))
+            if (!_packetDispatcher.TryDispatch(pubRecPacket))
             {
-                return CompletedTask.Instance;
+                // The packet is unknown. Probably due to a restart of the client.
+                // So wen send this to the server to trigger a full resend of the message.
+                var pubRelPacket = MqttPacketFactories.PubRel.Create(pubRecPacket, MqttApplicationMessageReceivedReasonCode.PacketIdentifierNotFound);
+                return Send(pubRelPacket, cancellationToken);
             }
 
-            // The packet is unknown, probably due to a restart of the client.
-            // So we send this to the server to trigger a full resend of the message.
-            var pubRelPacket = MqttPacketFactories.PubRel.Create(pubRecPacket, MqttApplicationMessageReceivedReasonCode.PacketIdentifierNotFound);
-            return Send(pubRelPacket, cancellationToken);
+            return CompletedTask.Instance;
         }
 
         Task ProcessReceivedPubRelPacket(MqttPubRelPacket pubRelPacket, CancellationToken cancellationToken)
@@ -791,27 +742,10 @@ namespace MQTTnet.Client
 
         async Task<MqttClientPublishResult> PublishAtMostOnce(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
         {
-            try
-            {
-                // No packet identifier is used for QoS 0 [3.3.2.2 Packet Identifier]
-                await Send(publishPacket, cancellationToken).ConfigureAwait(false);
+            // No packet identifier is used for QoS 0 [3.3.2.2 Packet Identifier]
+            await Send(publishPacket, cancellationToken).ConfigureAwait(false);
 
-                return MqttClientResultFactory.PublishResult.Create(null);
-            }
-            catch (Exception exception)
-            {
-                // We have to check if the server has sent a disconnect packet in response to the published message.
-                // Since we are in QoS 0 we do not get a direct response via an PUBACK packet and thus basically no
-                // feedback at all.
-                var localUnexpectedDisconnectPacket = _unexpectedDisconnectPacket;
-
-                if (localUnexpectedDisconnectPacket != null)
-                {
-                    throw new MqttClientUnexpectedDisconnectReceivedException(localUnexpectedDisconnectPacket, exception);
-                }
-
-                throw;
-            }
+            return MqttClientResultFactory.PublishResult.Create(null);
         }
 
         async Task<MqttClientPublishResult> PublishExactlyOnce(MqttPublishPacket publishPacket, CancellationToken cancellationToken)
@@ -848,7 +782,7 @@ namespace MQTTnet.Client
         {
             try
             {
-                _logger.Verbose("Start receiving packets");
+                _logger.Verbose("Start receiving packets.");
 
                 while (!cancellationToken.IsCancellationRequested)
                 {
@@ -886,21 +820,20 @@ namespace MQTTnet.Client
                 }
                 else if (exception is MqttCommunicationException)
                 {
-                    _logger.Warning(exception, "Communication error while receiving packets");
+                    _logger.Warning(exception, "Communication error while receiving packets.");
                 }
                 else
                 {
-                    _logger.Error(exception, "Error while receiving packets");
+                    _logger.Error(exception, "Error while receiving packets.");
                 }
 
-                // The packet dispatcher is set to null when the client is being disposed so it may already being gone!
-                _packetDispatcher?.FailAll(exception);
+                _packetDispatcher.FailAll(exception);
 
                 await DisconnectInternal(_packetReceiverTask, exception, null).ConfigureAwait(false);
             }
             finally
             {
-                _logger.Verbose("Stopped receiving packets");
+                _logger.Verbose("Stopped receiving packets.");
             }
         }
 
@@ -922,7 +855,7 @@ namespace MQTTnet.Client
                 }
                 catch (Exception exception)
                 {
-                    _logger.Warning(exception, "Error when sending {0} request packet", requestPacket.GetType().Name);
+                    _logger.Warning(exception, "Error when sending request packet ({0}).", requestPacket.GetType().Name);
                     packetAwaitable.Fail(exception);
                 }
 
@@ -934,7 +867,7 @@ namespace MQTTnet.Client
                 {
                     if (exception is MqttCommunicationTimedOutException)
                     {
-                        _logger.Warning("Timeout while waiting for {0} response packet", typeof(TResponsePacket).Name);
+                        _logger.Warning("Timeout while waiting for response packet ({0}).", typeof(TResponsePacket).Name);
                     }
 
                     throw;
@@ -948,6 +881,7 @@ namespace MQTTnet.Client
 
             _lastPacketSentTimestamp = DateTime.UtcNow;
 
+            //ThrowIfNotConnected();
             return _adapter.SendPacketAsync(packet, cancellationToken);
         }
 
@@ -967,14 +901,6 @@ namespace MQTTnet.Client
             }
         }
 
-        void ThrowIfNotConnectedOrConnecting()
-        {
-            if (!(IsConnected || IsConnecting))
-            {
-                ThrowNotConnectedOrConnecting();
-            }
-        }
-
         static void ThrowIfOptionsInvalid(MqttClientOptions options)
         {
             if (options == null)
@@ -995,12 +921,7 @@ namespace MQTTnet.Client
 
         static void ThrowNotConnected()
         {
-            throw new MqttClientNotConnectedException();
-        }
-
-        static void ThrowNotConnectedOrConnecting()
-        {
-            throw new MqttCommunicationException("The MQTT client is not connected or connecting.");
+            throw new MqttCommunicationException("The client is not connected.");
         }
 
         void TryInitiateDisconnect()
@@ -1013,7 +934,7 @@ namespace MQTTnet.Client
                 }
                 catch (Exception exception)
                 {
-                    _logger.Warning(exception, "Error while initiating disconnect");
+                    _logger.Warning(exception, "Error while initiating disconnect.");
                 }
             }
         }
@@ -1022,36 +943,39 @@ namespace MQTTnet.Client
         {
             try
             {
-                switch (packet)
+                if (packet is MqttPublishPacket publishPacket)
                 {
-                    case MqttPublishPacket publishPacket:
-                        EnqueueReceivedPublishPacket(publishPacket);
-                        break;
-                    case MqttPubRecPacket pubRecPacket:
-                        await ProcessReceivedPubRecPacket(pubRecPacket, cancellationToken).ConfigureAwait(false);
-                        break;
-                    case MqttPubRelPacket pubRelPacket:
-                        await ProcessReceivedPubRelPacket(pubRelPacket, cancellationToken).ConfigureAwait(false);
-                        break;
-                    case MqttDisconnectPacket disconnectPacket:
-                        await ProcessReceivedDisconnectPacket(disconnectPacket).ConfigureAwait(false);
-                        break;
-                    case MqttAuthPacket authPacket:
-                        await ProcessReceivedAuthPacket(authPacket, cancellationToken).ConfigureAwait(false);
-                        break;
-                    case MqttPingRespPacket _:
-                        _packetDispatcher.TryDispatch(packet);
-                        break;
-                    case MqttPingReqPacket _:
-                        throw new MqttProtocolViolationException("The PINGREQ Packet is sent from a client to the server only.");
-                    default:
+                    EnqueueReceivedPublishPacket(publishPacket);
+                }
+                else if (packet is MqttPubRecPacket pubRecPacket)
+                {
+                    await ProcessReceivedPubRecPacket(pubRecPacket, cancellationToken).ConfigureAwait(false);
+                }
+                else if (packet is MqttPubRelPacket pubRelPacket)
+                {
+                    await ProcessReceivedPubRelPacket(pubRelPacket, cancellationToken).ConfigureAwait(false);
+                }
+                else if (packet is MqttDisconnectPacket disconnectPacket)
+                {
+                    await ProcessReceivedDisconnectPacket(disconnectPacket).ConfigureAwait(false);
+                }
+                else if (packet is MqttAuthPacket authPacket)
+                {
+                    await ProcessReceivedAuthPacket(authPacket).ConfigureAwait(false);
+                }
+                else if (packet is MqttPingRespPacket)
+                {
+                    _packetDispatcher.TryDispatch(packet);
+                }
+                else if (packet is MqttPingReqPacket)
+                {
+                    throw new MqttProtocolViolationException("The PINGREQ Packet is sent from a Client to the Server only.");
+                }
+                else
+                {
+                    if (!_packetDispatcher.TryDispatch(packet))
                     {
-                        if (!_packetDispatcher.TryDispatch(packet))
-                        {
-                            throw new MqttProtocolViolationException($"Received packet '{packet}' at an unexpected time.");
-                        }
-
-                        break;
+                        throw new MqttProtocolViolationException($"Received packet '{packet}' at an unexpected time.");
                     }
                 }
             }
@@ -1062,20 +986,19 @@ namespace MQTTnet.Client
                     return;
                 }
 
-                switch (exception)
+                if (exception is OperationCanceledException)
                 {
-                    case OperationCanceledException _:
-                        break;
-                    case MqttCommunicationException _:
-                        _logger.Warning(exception, "Communication error while receiving packets");
-                        break;
-                    default:
-                        _logger.Error(exception, "Error while processing received {0} packet", packet.GetType().Name);
-                        break;
+                }
+                else if (exception is MqttCommunicationException)
+                {
+                    _logger.Warning(exception, "Communication error while receiving packets.");
+                }
+                else
+                {
+                    _logger.Error(exception, $"Error while processing received packet ({packet.GetType().Name}).");
                 }
 
-                // The packet dispatcher may already be gone due to disconnect etc.!
-                _packetDispatcher?.FailAll(exception);
+                _packetDispatcher.FailAll(exception);
 
                 await DisconnectInternal(_packetReceiverTask, exception, null).ConfigureAwait(false);
             }
@@ -1085,7 +1008,7 @@ namespace MQTTnet.Client
         {
             try
             {
-                _logger.Verbose("Start sending keep alive packets");
+                _logger.Verbose("Start sending keep alive packets.");
 
                 var keepAlivePeriod = Options.KeepAlivePeriod;
 
@@ -1096,13 +1019,10 @@ namespace MQTTnet.Client
 
                     if (timeWithoutPacketSent > keepAlivePeriod)
                     {
-                        using (var pingTimeout = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken))
+                        using (var timeoutCancellationTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken))
                         {
-                            // We already reached the keep alive timeout. Due to the RFC part [MQTT-3.1.2-24] the server will wait another
-                            // 1/2 of the keep alive time. So we can also use this value as the timeout.
-                            pingTimeout.CancelAfter((int)(keepAlivePeriod.TotalMilliseconds / 2));
-
-                            await PingAsync(pingTimeout.Token).ConfigureAwait(false);
+                            timeoutCancellationTokenSource.CancelAfter(Options.Timeout);
+                            await PingAsync(timeoutCancellationTokenSource.Token).ConfigureAwait(false);
                         }
                     }
 
@@ -1120,23 +1040,24 @@ namespace MQTTnet.Client
                     return;
                 }
 
-                switch (exception)
+                if (exception is OperationCanceledException)
                 {
-                    case OperationCanceledException _:
-                        return;
-                    case MqttCommunicationException _:
-                        _logger.Warning(exception, "Communication error while sending/receiving keep alive packets");
-                        break;
-                    default:
-                        _logger.Error(exception, "Error exception while sending/receiving keep alive packets");
-                        break;
+                    return;
+                }
+                else if (exception is MqttCommunicationException)
+                {
+                    _logger.Warning(exception, "Communication error while sending/receiving keep alive packets.");
+                }
+                else
+                {
+                    _logger.Error(exception, "Error exception while sending/receiving keep alive packets.");
                 }
 
                 await DisconnectInternal(_keepAlivePacketsSenderTask, exception, null).ConfigureAwait(false);
             }
             finally
             {
-                _logger.Verbose("Stopped sending keep alive packets");
+                _logger.Verbose("Stopped sending keep alive packets.");
             }
         }
     }

Source/MQTTnet/Client/Options/DefaultMqttCertificatesProvider.cs

@@ -1,36 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System.Collections.Generic;
-using System.Security.Cryptography.X509Certificates;
-
-namespace MQTTnet.Client
-{
-    public sealed class DefaultMqttCertificatesProvider : IMqttClientCertificatesProvider
-    {
-        readonly X509Certificate2Collection _certificates;
-
-        public DefaultMqttCertificatesProvider(X509Certificate2Collection certificates)
-        {
-            _certificates = certificates;
-        }
-
-        public DefaultMqttCertificatesProvider(IEnumerable<X509Certificate> certificates)
-        {
-            if (certificates != null)
-            {
-                _certificates = new X509Certificate2Collection();
-                foreach (var certificate in certificates)
-                {
-                    _certificates.Add(certificate);
-                }
-            }
-        }
-
-        public X509CertificateCollection GetCertificates()
-        {
-            return _certificates;
-        }
-    }
-}

Source/MQTTnet/Client/Options/IMqttClientCertificatesProvider.cs

@@ -1,11 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-namespace MQTTnet.Client
-{
-    public interface IMqttClientCertificatesProvider
-    {
-        System.Security.Cryptography.X509Certificates.X509CertificateCollection GetCertificates();
-    }
-}

Source/MQTTnet/Client/Options/MqttClientCertificateSelectionEventArgs.cs

@@ -1,36 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-using System.Security.Cryptography.X509Certificates;
-
-namespace MQTTnet.Client
-{
-    public sealed class MqttClientCertificateSelectionEventArgs : EventArgs
-    {
-        public MqttClientCertificateSelectionEventArgs(
-            string targetHost,
-            X509CertificateCollection localCertificates,
-            X509Certificate remoteCertificate,
-            string[] acceptableIssuers,
-            MqttClientTcpOptions tcpOptions)
-        {
-            TargetHost = targetHost;
-            LocalCertificates = localCertificates;
-            RemoveCertificate = remoteCertificate;
-            AcceptableIssuers = acceptableIssuers;
-            TcpOptions = tcpOptions ?? throw new ArgumentNullException(nameof(tcpOptions));
-        }
-
-        public string[] AcceptableIssuers { get; }
-
-        public X509CertificateCollection LocalCertificates { get; }
-
-        public X509Certificate RemoveCertificate { get; }
-
-        public string TargetHost { get; }
-
-        public MqttClientTcpOptions TcpOptions { get; }
-    }
-}

Source/MQTTnet/Client/Options/MqttClientCertificateValidationEventArgs.cs

@@ -10,27 +10,12 @@ namespace MQTTnet.Client
 {
     public sealed class MqttClientCertificateValidationEventArgs : EventArgs
     {
-        public MqttClientCertificateValidationEventArgs(X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors, IMqttClientChannelOptions clientOptions)
-        {
-            Certificate = certificate;
-            Chain = chain;
-            SslPolicyErrors = sslPolicyErrors;
-            ClientOptions = clientOptions ?? throw new ArgumentNullException(nameof(clientOptions));
-        }
+        public X509Certificate Certificate { get; set; }
 
-        public X509Certificate Certificate { get; }
+        public X509Chain Chain { get; set; }
 
-        public X509Chain Chain { get; }
+        public SslPolicyErrors SslPolicyErrors { get; set; }
 
-        public IMqttClientChannelOptions ClientOptions { get; }
-
-#if NET452 || NET461 || NET48
-        /// <summary>
-        ///     Can be a host string name or an object derived from WebRequest.
-        /// </summary>
-        public object Sender { get; set; }
-#endif
-
-        public SslPolicyErrors SslPolicyErrors { get; }
+        public IMqttClientChannelOptions ClientOptions { get; set; }
     }
-}
+}

Source/MQTTnet/Client/Options/MqttClientOptionsBuilder.cs

@@ -2,13 +2,9 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-#pragma warning disable CS0612 // Type or member is obsolete
-
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Net;
-using System.Net.Sockets;
 using System.Text;
 using MQTTnet.Formatter;
 using MQTTnet.Packets;
@@ -19,16 +15,10 @@ namespace MQTTnet.Client
     public sealed class MqttClientOptionsBuilder
     {
         readonly MqttClientOptions _options = new MqttClientOptions();
-        int? _port;
-
-        [Obsolete] MqttClientWebSocketProxyOptions _proxyOptions;
-        EndPoint _remoteEndPoint;
+        MqttClientWebSocketProxyOptions _proxyOptions;
 
         MqttClientTcpOptions _tcpOptions;
-        MqttClientTlsOptions _tlsOptions;
-
-        [Obsolete] MqttClientOptionsBuilderTlsParameters _tlsParameters;
-
+        MqttClientOptionsBuilderTlsParameters _tlsParameters;
         MqttClientWebSocketOptions _webSocketOptions;
 
         public MqttClientOptions Build()
@@ -38,17 +28,11 @@ namespace MQTTnet.Client
                 throw new InvalidOperationException("A channel must be set.");
             }
 
-            // The user can specify the TCP options with already configured TLS options
-            // or start with TLS settings not knowing which transport will be used (depending
-            // on the order of called methods from the builder).
-            // The builder prefers the explicitly set TLS options!
-            var tlsOptions = _tlsOptions ?? _tcpOptions?.TlsOptions;
-
             if (_tlsParameters != null)
             {
                 if (_tlsParameters?.UseTls == true)
                 {
-                    tlsOptions = new MqttClientTlsOptions
+                    var tlsOptions = new MqttClientTlsOptions
                     {
                         UseTls = true,
                         SslProtocol = _tlsParameters.SslProtocol,
@@ -56,61 +40,26 @@ namespace MQTTnet.Client
                         CertificateValidationHandler = _tlsParameters.CertificateValidationHandler,
                         IgnoreCertificateChainErrors = _tlsParameters.IgnoreCertificateChainErrors,
                         IgnoreCertificateRevocationErrors = _tlsParameters.IgnoreCertificateRevocationErrors,
-                        ClientCertificatesProvider = _tlsParameters.CertificatesProvider,
+#if WINDOWS_UWP
+                        Certificates = _tlsParameters.Certificates?.Select(c => c.ToArray()).ToList(),
+#else
+                        Certificates = _tlsParameters.Certificates?.ToList(),
+#endif
+
 #if NETCOREAPP3_1_OR_GREATER
                         ApplicationProtocols = _tlsParameters.ApplicationProtocols,
 #endif
                     };
-                }
-            }
 
-            if (_tcpOptions != null)
-            {
-                _tcpOptions.TlsOptions = tlsOptions;
-
-                if (_remoteEndPoint == null)
-                {
-                    throw new ArgumentException("No endpoint is set.");
-                }
-
-                if (_remoteEndPoint is DnsEndPoint dns)
-                {
-                    if (dns.Port == 0)
+                    if (_tcpOptions != null)
                     {
-                        if (_port.HasValue)
-                        {
-                            _remoteEndPoint = new DnsEndPoint(dns.Host, _port.Value, dns.AddressFamily);
-                        }
-                        else
-                        {
-                            _remoteEndPoint = new DnsEndPoint(dns.Host, tlsOptions?.UseTls == false ? MqttPorts.Default : MqttPorts.Secure, dns.AddressFamily);
-                        }
+                        _tcpOptions.TlsOptions = tlsOptions;
+                    }
+                    else if (_webSocketOptions != null)
+                    {
+                        _webSocketOptions.TlsOptions = tlsOptions;
                     }
                 }
-
-                if (_remoteEndPoint is IPEndPoint ip)
-                {
-                    if (ip.Port == 0)
-                    {
-                        if (_port.HasValue)
-                        {
-                            _remoteEndPoint = new IPEndPoint(ip.Address, _port.Value);
-                        }
-                        else
-                        {
-                            _remoteEndPoint = new IPEndPoint(ip.Address, tlsOptions?.UseTls == false ? MqttPorts.Default : MqttPorts.Secure);
-                        }
-                    }
-                }
-
-                if (_tcpOptions.RemoteEndpoint == null)
-                {
-                    _tcpOptions.RemoteEndpoint = _remoteEndPoint;
-                }
-            }
-            else if (_webSocketOptions != null)
-            {
-                _webSocketOptions.TlsOptions = tlsOptions;
             }
 
             if (_proxyOptions != null)
@@ -129,13 +78,17 @@ namespace MQTTnet.Client
 
             return _options;
         }
-
-        public MqttClientOptionsBuilder WithAddressFamily(AddressFamily addressFamily)
+        
+        /// <summary>
+        /// The client will not throw an exception when the MQTT server responses with a non success ACK packet.
+        /// This will become the default behavior in future versions of the library.
+        /// </summary>
+        public MqttClientOptionsBuilder WithoutThrowOnNonSuccessfulConnectResponse()
         {
-            _tcpOptions.AddressFamily = addressFamily;
+            _options.ThrowOnNonSuccessfulConnectResponse = false;
             return this;
         }
-
+        
         public MqttClientOptionsBuilder WithAuthentication(string method, byte[] data)
         {
             _options.AuthenticationMethod = method;
@@ -183,16 +136,12 @@ namespace MQTTnet.Client
                     break;
 
                 case "mqtts":
-                    WithTcpServer(uri.Host, port)
-                        .WithTlsOptions(
-                            o =>
-                            {
-                            });
+                    WithTcpServer(uri.Host, port).WithTls();
                     break;
 
                 case "ws":
                 case "wss":
-                    WithWebSocketServer(o => o.WithUri(uri.ToString()));
+                    WithWebSocketServer(uri.ToString());
                     break;
 
                 default:
@@ -238,14 +187,6 @@ namespace MQTTnet.Client
             return this;
         }
 
-        public MqttClientOptionsBuilder WithEndPoint(EndPoint endPoint)
-        {
-            _remoteEndPoint = endPoint ?? throw new ArgumentNullException(nameof(endPoint));
-            _tcpOptions = new MqttClientTcpOptions();
-
-            return this;
-        }
-
         public MqttClientOptionsBuilder WithExtendedAuthenticationExchangeHandler(IMqttExtendedAuthenticationExchangeHandler handler)
         {
             _options.ExtendedAuthenticationExchangeHandler = handler;
@@ -281,22 +222,6 @@ namespace MQTTnet.Client
             return this;
         }
 
-        /// <summary>
-        ///     The client will not throw an exception when the MQTT server responds with a non success ACK packet.
-        ///     This will become the default behavior in future versions of the library.
-        /// </summary>
-        public MqttClientOptionsBuilder WithoutThrowOnNonSuccessfulConnectResponse()
-        {
-            _options.ThrowOnNonSuccessfulConnectResponse = false;
-            return this;
-        }
-
-        public MqttClientOptionsBuilder WithProtocolType(ProtocolType protocolType)
-        {
-            _tcpOptions.ProtocolType = protocolType;
-            return this;
-        }
-
         public MqttClientOptionsBuilder WithProtocolVersion(MqttProtocolVersion value)
         {
             if (value == MqttProtocolVersion.Unknown)
@@ -308,7 +233,6 @@ namespace MQTTnet.Client
             return this;
         }
 
-        [Obsolete("Use WithWebSocketServer(... configure) instead.")]
         public MqttClientOptionsBuilder WithProxy(
             string address,
             string username = null,
@@ -330,7 +254,6 @@ namespace MQTTnet.Client
             return this;
         }
 
-        [Obsolete("Use WithWebSocketServer(... configure) instead.")]
         public MqttClientOptionsBuilder WithProxy(Action<MqttClientWebSocketProxyOptions> optionsBuilder)
         {
             if (optionsBuilder == null)
@@ -367,19 +290,13 @@ namespace MQTTnet.Client
             return this;
         }
 
-        public MqttClientOptionsBuilder WithTcpServer(string host, int? port = null, AddressFamily addressFamily = AddressFamily.Unspecified)
+        public MqttClientOptionsBuilder WithTcpServer(string server, int? port = null)
         {
-            if (host == null)
+            _tcpOptions = new MqttClientTcpOptions
             {
-                throw new ArgumentNullException(nameof(host));
-            }
-
-            _tcpOptions = new MqttClientTcpOptions();
-
-            // The value 0 will be updated when building the options.
-            // This a backward compatibility feature.
-            _remoteEndPoint = new DnsEndPoint(host, port ?? 0, addressFamily);
-            _port = port;
+                Server = server,
+                Port = port
+            };
 
             return this;
         }
@@ -407,20 +324,17 @@ namespace MQTTnet.Client
             return this;
         }
 
-        [Obsolete("Use WithTlsOptions(... configure) instead.")]
         public MqttClientOptionsBuilder WithTls(MqttClientOptionsBuilderTlsParameters parameters)
         {
             _tlsParameters = parameters;
             return this;
         }
 
-        [Obsolete("Use WithTlsOptions(... configure) instead.")]
         public MqttClientOptionsBuilder WithTls()
         {
             return WithTls(new MqttClientOptionsBuilderTlsParameters { UseTls = true });
         }
 
-        [Obsolete("Use WithTlsOptions(... configure) instead.")]
         public MqttClientOptionsBuilder WithTls(Action<MqttClientOptionsBuilderTlsParameters> optionsBuilder)
         {
             if (optionsBuilder == null)
@@ -437,26 +351,6 @@ namespace MQTTnet.Client
             return this;
         }
 
-        public MqttClientOptionsBuilder WithTlsOptions(MqttClientTlsOptions tlsOptions)
-        {
-            _tlsOptions = tlsOptions;
-            return this;
-        }
-
-        public MqttClientOptionsBuilder WithTlsOptions(Action<MqttClientTlsOptionsBuilder> configure)
-        {
-            if (configure == null)
-            {
-                throw new ArgumentNullException(nameof(configure));
-            }
-
-            var builder = new MqttClientTlsOptionsBuilder();
-            configure.Invoke(builder);
-
-            _tlsOptions = builder.Build();
-            return this;
-        }
-
         public MqttClientOptionsBuilder WithTopicAliasMaximum(ushort topicAliasMaximum)
         {
             _options.TopicAliasMaximum = topicAliasMaximum;
@@ -488,7 +382,6 @@ namespace MQTTnet.Client
             return this;
         }
 
-        [Obsolete("Use WithWebSocketServer(... configure) instead.")]
         public MqttClientOptionsBuilder WithWebSocketServer(string uri, MqttClientOptionsBuilderWebSocketParameters parameters = null)
         {
             _webSocketOptions = new MqttClientWebSocketOptions
@@ -501,21 +394,6 @@ namespace MQTTnet.Client
             return this;
         }
 
-        public MqttClientOptionsBuilder WithWebSocketServer(Action<MqttClientWebSocketOptionsBuilder> configure)
-        {
-            if (configure == null)
-            {
-                throw new ArgumentNullException(nameof(configure));
-            }
-
-            var webSocketOptionsBuilder = new MqttClientWebSocketOptionsBuilder();
-            configure.Invoke(webSocketOptionsBuilder);
-
-            _webSocketOptions = webSocketOptionsBuilder.Build();
-            return this;
-        }
-
-        [Obsolete("Use WithWebSocketServer(... configure) instead.")]
         public MqttClientOptionsBuilder WithWebSocketServer(Action<MqttClientWebSocketOptions> optionsBuilder)
         {
             if (optionsBuilder == null)
@@ -547,12 +425,6 @@ namespace MQTTnet.Client
             return this;
         }
 
-        public MqttClientOptionsBuilder WithWillMessageExpiryInterval(uint willMessageExpiryInterval)
-        {
-            _options.WillMessageExpiryInterval = willMessageExpiryInterval;
-            return this;
-        }
-
         public MqttClientOptionsBuilder WithWillPayload(byte[] willPayload)
         {
             _options.WillPayload = willPayload;

Source/MQTTnet/Client/Options/MqttClientOptionsBuilderTlsParameters.cs

@@ -5,14 +5,12 @@
 using System;
 using System.Collections.Generic;
 using System.Security.Authentication;
+using System.Security.Cryptography.X509Certificates;
 
 namespace MQTTnet.Client
 {
-    [Obsolete("Use methods from MqttClientOptionsBuilder instead.")]
     public sealed class MqttClientOptionsBuilderTlsParameters
     {
-        IEnumerable<System.Security.Cryptography.X509Certificates.X509Certificate> _obsoleteCertificates;
-
         public bool UseTls { get; set; }
 
         public Func<MqttClientCertificateValidationEventArgs, bool> CertificateValidationHandler { get; set; }
@@ -26,24 +24,7 @@ namespace MQTTnet.Client
 #if WINDOWS_UWP
         public IEnumerable<IEnumerable<byte>> Certificates { get; set; }
 #else
-        [Obsolete("Use CertificatesProvider instead.")]
-        public IEnumerable<System.Security.Cryptography.X509Certificates.X509Certificate> Certificates
-        {
-            get => _obsoleteCertificates;
-            set
-            {
-                _obsoleteCertificates = value;
-
-                if (value == null)
-                {
-                    CertificatesProvider = null;
-                }
-                else
-                {
-                    CertificatesProvider = new DefaultMqttCertificatesProvider(value);
-                }
-            }
-        }
+        public IEnumerable<X509Certificate> Certificates { get; set; }
 #endif
 
 #if NETCOREAPP3_1_OR_GREATER
@@ -55,7 +36,5 @@ namespace MQTTnet.Client
         public bool IgnoreCertificateChainErrors { get; set; }
 
         public bool IgnoreCertificateRevocationErrors { get; set; }
-
-        public IMqttClientCertificatesProvider CertificatesProvider { get; set; }
     }
 }

Source/MQTTnet/Client/Options/MqttClientOptionsBuilderWebSocketParameters.cs

@@ -2,13 +2,11 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using System.Collections.Generic;
 using System.Net;
 
 namespace MQTTnet.Client
 {
-    [Obsolete("Use dedicated methods in MqttClientOptionsBuilder.")]
     public class MqttClientOptionsBuilderWebSocketParameters
     {
         public IDictionary<string, string> RequestHeaders { get; set; }

Source/MQTTnet/Client/Options/MqttClientOptionsValidator.cs

@@ -68,13 +68,8 @@ namespace MQTTnet.Client
                 Throw(nameof(options.AuthenticationMethod));
             }
 
-            if (options.ExtendedAuthenticationExchangeHandler != null)
-            {
-                Throw(nameof(options.ExtendedAuthenticationExchangeHandler));
-            }
-
             // Will relevant properties.
-
+            
             if (options.WillPayloadFormatIndicator != MqttPayloadFormatIndicator.Unspecified)
             {
                 Throw(nameof(options.WillPayloadFormatIndicator));

Source/MQTTnet/Client/Options/MqttClientTcpOptions.cs

@@ -2,105 +2,43 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using System.Net;
 using System.Net.Sockets;
-using MQTTnet.Protocol;
 
 namespace MQTTnet.Client
 {
     public sealed class MqttClientTcpOptions : IMqttClientChannelOptions
     {
-        EndPoint _remoteEndpoint;
         public AddressFamily AddressFamily { get; set; } = AddressFamily.Unspecified;
 
+        /// <summary>
+        /// Gets the local endpoint (network card) which is used by the client.
+        /// Set it to _null_ to let the OS select the network card.
+        /// </summary>
+        public EndPoint LocalEndpoint { get; set; }
+        
         public int BufferSize { get; set; } = 8192;
 
         /// <summary>
-        ///     Gets or sets whether the underlying socket should run in dual mode.
-        ///     Leaving this _null_ will avoid setting this value at socket level.
-        ///     Setting this a value other than _null_ will throw an exception when only IPv4 is supported on the machine.
+        /// Gets or sets whether the underlying socket should run in dual mode.
+        /// Leaving this _null_ will avoid setting this value at socket level.
+        /// Setting this a value other than _null_ will throw an exception when only IPv4 is supported on the machine.
         /// </summary>
         public bool? DualMode { get; set; }
 
-        [Obsolete("Use RemoteEndpoint or MqttClientOptionsBuilder instead.")]
-        public int? Port { get; set; }
-
-        [Obsolete("Use RemoteEndpoint or MqttClientOptionsBuilder instead.")]
-        public string Server { get; set; }
-
         public LingerOption LingerState { get; set; } = new LingerOption(true, 0);
 
-        /// <summary>
-        ///     Gets the local endpoint (network card) which is used by the client.
-        ///     Set it to _null_ to let the OS select the network card.
-        /// </summary>
-        public EndPoint LocalEndpoint { get; set; }
-
-        /// <summary>
-        ///     Enables or disables the Nagle algorithm for the socket.
-        ///     This is only supported for TCP.
-        ///     For other protocol types the value is ignored.
-        ///     Default: true
-        /// </summary>
         public bool NoDelay { get; set; } = true;
 
-        /// <summary>
-        ///     The MQTT transport is usually TCP but when using other endpoint types like
-        ///     unix sockets it must be changed (IP for unix sockets).
-        /// </summary>
-        public ProtocolType ProtocolType { get; set; } = ProtocolType.Tcp;
-
-        public EndPoint RemoteEndpoint
-        {
-            get => _remoteEndpoint;
-            set
-            {
-                _remoteEndpoint = value;
-
-                if (_remoteEndpoint is DnsEndPoint dnsEndPoint)
-                {
-                    Server = dnsEndPoint.Host;
-                    Port = dnsEndPoint.Port;
-                }
-                else if (_remoteEndpoint is IPEndPoint ipEndPoint)
-                {
-                    Server = ipEndPoint.Address.ToString();
-                    Port = ipEndPoint.Port;
-                }
-            }
-        }
+        public int? Port { get; set; }
+        
+        public string Server { get; set; }
 
         public MqttClientTlsOptions TlsOptions { get; set; } = new MqttClientTlsOptions();
 
         public override string ToString()
         {
-            if (RemoteEndpoint != null)
-            {
-                return RemoteEndpoint.ToString();
-            }
-
-            if (!string.IsNullOrEmpty(Server))
-            {
-                return $"{Server}:{GetPort()}";
-            }
-
-            return string.Empty;
-        }
-
-        int GetPort()
-        {
-            if (Port.HasValue)
-            {
-                return Port.Value;
-            }
-
-            if (TlsOptions?.UseTls == true)
-            {
-                return MqttPorts.Secure;
-            }
-
-            return MqttPorts.Default;
+            return Server + ":" + this.GetPort();
         }
     }
 }

Source/MQTTnet/Client/Options/MqttClientTcpOptionsExtensions.cs

@@ -0,0 +1,23 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+
+namespace MQTTnet.Client
+{
+    public static class MqttClientTcpOptionsExtensions
+    {
+        public static int GetPort(this MqttClientTcpOptions options)
+        {
+            if (options == null) throw new ArgumentNullException(nameof(options));
+
+            if (options.Port.HasValue)
+            {
+                return options.Port.Value;
+            }
+
+            return !options.TlsOptions.UseTls ? 1883 : 8883;
+        }
+    }
+}

Source/MQTTnet/Client/Options/MqttClientTlsOptions.cs

@@ -14,8 +14,6 @@ namespace MQTTnet.Client
     {
         public Func<MqttClientCertificateValidationEventArgs, bool> CertificateValidationHandler { get; set; }
 
-        public Func<MqttClientCertificateSelectionEventArgs, X509Certificate> CertificateSelectionHandler { get; set; }
-
         public bool UseTls { get; set; }
 
         public bool IgnoreCertificateRevocationErrors { get; set; }
@@ -26,13 +24,11 @@ namespace MQTTnet.Client
 
         public X509RevocationMode RevocationMode { get; set; } = X509RevocationMode.Online;
 
-        /// <summary>
-        ///     Gets or sets the provider for certificates.
-        ///     This provider gets called whenever the client wants to connect
-        ///     with the server and requires certificates for authentication.
-        ///     The implementation may return different certificates each time.
-        /// </summary>
-        public IMqttClientCertificatesProvider ClientCertificatesProvider { get; set; }
+#if WINDOWS_UWP
+        public List<byte[]> Certificates { get; set; }
+#else
+        public List<X509Certificate> Certificates { get; set; }
+#endif
 
 #if NETCOREAPP3_1_OR_GREATER
         public List<SslApplicationProtocol> ApplicationProtocols { get; set; }
@@ -52,13 +48,8 @@ namespace MQTTnet.Client
 
 #if NET48 || NETCOREAPP3_1_OR_GREATER
         public SslProtocols SslProtocol { get; set; } = SslProtocols.Tls12 | SslProtocols.Tls13;
-
 #else
         public SslProtocols SslProtocol { get; set; } = SslProtocols.Tls12 | (SslProtocols)0x00003000 /*Tls13*/;
 #endif
-
-#if NET7_0_OR_GREATER
-        public X509Certificate2Collection TrustChain { get; set; }
-#endif
     }
 }

Source/MQTTnet/Client/Options/MqttClientTlsOptionsBuilder.cs

@@ -1,156 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-using System.Collections.Generic;
-using System.Security.Authentication;
-using System.Security.Cryptography.X509Certificates;
-#if NETCOREAPP3_1_OR_GREATER
-using System.Net.Security;
-#endif
-
-namespace MQTTnet.Client
-{
-    public sealed class MqttClientTlsOptionsBuilder
-    {
-        readonly MqttClientTlsOptions _tlsOptions = new MqttClientTlsOptions
-        {
-            // If someone used this builder the change is very very high that TLS
-            // should be actually used.
-            UseTls = true
-        };
-
-        public MqttClientTlsOptions Build()
-        {
-            return _tlsOptions;
-        }
-
-        public MqttClientTlsOptionsBuilder UseTls(bool useTls = true)
-        {
-            _tlsOptions.UseTls = useTls;
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithAllowUntrustedCertificates(bool allowUntrustedCertificates = true)
-        {
-            _tlsOptions.AllowUntrustedCertificates = allowUntrustedCertificates;
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithCertificateValidationHandler(Func<MqttClientCertificateValidationEventArgs, bool> certificateValidationHandler)
-        {
-            if (certificateValidationHandler == null)
-            {
-                throw new ArgumentNullException(nameof(certificateValidationHandler));
-            }
-
-            _tlsOptions.CertificateValidationHandler = certificateValidationHandler;
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithCertificateSelectionHandler(Func<MqttClientCertificateSelectionEventArgs, X509Certificate> certificateSelectionHandler)
-        {
-            if (certificateSelectionHandler == null)
-            {
-                throw new ArgumentNullException(nameof(certificateSelectionHandler));
-            }
-
-            _tlsOptions.CertificateSelectionHandler = certificateSelectionHandler;
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithClientCertificates(IEnumerable<X509Certificate2> certificates)
-        {
-            if (certificates == null)
-            {
-                throw new ArgumentNullException(nameof(certificates));
-            }
-
-            _tlsOptions.ClientCertificatesProvider = new DefaultMqttCertificatesProvider(certificates);
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithClientCertificates(X509Certificate2Collection certificates)
-        {
-            if (certificates == null)
-            {
-                throw new ArgumentNullException(nameof(certificates));
-            }
-
-            _tlsOptions.ClientCertificatesProvider = new DefaultMqttCertificatesProvider(certificates);
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithClientCertificatesProvider(IMqttClientCertificatesProvider clientCertificatesProvider)
-        {
-            _tlsOptions.ClientCertificatesProvider = clientCertificatesProvider;
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithIgnoreCertificateChainErrors(bool ignoreCertificateChainErrors = true)
-        {
-            _tlsOptions.IgnoreCertificateChainErrors = ignoreCertificateChainErrors;
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithIgnoreCertificateRevocationErrors(bool ignoreCertificateRevocationErrors = true)
-        {
-            _tlsOptions.IgnoreCertificateRevocationErrors = ignoreCertificateRevocationErrors;
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithRevocationMode(X509RevocationMode revocationMode)
-        {
-            _tlsOptions.RevocationMode = revocationMode;
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithSslProtocols(SslProtocols sslProtocols)
-        {
-            _tlsOptions.SslProtocol = sslProtocols;
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithTargetHost(string targetHost)
-        {
-            _tlsOptions.TargetHost = targetHost;
-            return this;
-        }
-
-#if NETCOREAPP3_1_OR_GREATER
-        public MqttClientTlsOptionsBuilder WithAllowRenegotiation(bool allowRenegotiation = true)
-        {
-            _tlsOptions.AllowRenegotiation = allowRenegotiation;
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithApplicationProtocols(List<SslApplicationProtocol> applicationProtocols)
-        {
-            _tlsOptions.ApplicationProtocols = applicationProtocols;
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithCipherSuitesPolicy(CipherSuitesPolicy cipherSuitePolicy)
-        {
-            _tlsOptions.CipherSuitesPolicy = cipherSuitePolicy;
-            return this;
-        }
-
-        public MqttClientTlsOptionsBuilder WithCipherSuitesPolicy(EncryptionPolicy encryptionPolicy)
-        {
-            _tlsOptions.EncryptionPolicy = encryptionPolicy;
-            return this;
-        }
-#endif
-
-#if NET7_0_OR_GREATER
-        public MqttClientTlsOptionsBuilder WithTrustChain(X509Certificate2Collection chain)
-        {
-            _tlsOptions.TrustChain = chain;
-            return this;
-        }
-
-#endif
-    }
-}

Source/MQTTnet/Client/Options/MqttClientWebSocketOptionsBuilder.cs

@@ -1,85 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-using System.Collections.Generic;
-using System.Net;
-
-namespace MQTTnet.Client
-{
-    public sealed class MqttClientWebSocketOptionsBuilder
-    {
-        readonly MqttClientWebSocketOptions _webSocketOptions = new MqttClientWebSocketOptions();
-
-        public MqttClientWebSocketOptions Build()
-        {
-            return _webSocketOptions;
-        }
-
-        public MqttClientWebSocketOptionsBuilder WithCookieContainer(CookieContainer cookieContainer)
-        {
-            _webSocketOptions.CookieContainer = cookieContainer;
-            return this;
-        }
-
-        public MqttClientWebSocketOptionsBuilder WithCookieContainer(ICredentials credentials)
-        {
-            _webSocketOptions.Credentials = credentials;
-            return this;
-        }
-
-        public MqttClientWebSocketOptionsBuilder WithProxyOptions(MqttClientWebSocketProxyOptions proxyOptions)
-        {
-            _webSocketOptions.ProxyOptions = proxyOptions;
-            return this;
-        }
-
-        public MqttClientWebSocketOptionsBuilder WithProxyOptions(Action<MqttClientWebSocketProxyOptionsBuilder> configure)
-        {
-            if (configure == null)
-            {
-                throw new ArgumentNullException(nameof(configure));
-            }
-
-            var proxyOptionsBuilder = new MqttClientWebSocketProxyOptionsBuilder();
-            configure.Invoke(proxyOptionsBuilder);
-
-            _webSocketOptions.ProxyOptions = proxyOptionsBuilder.Build();
-            return this;
-        }
-
-        public MqttClientWebSocketOptionsBuilder WithRequestHeaders(IDictionary<string, string> requestHeaders)
-        {
-            _webSocketOptions.RequestHeaders = requestHeaders;
-            return this;
-        }
-
-        public MqttClientWebSocketOptionsBuilder WithSubProtocols(ICollection<string> subProtocols)
-        {
-            _webSocketOptions.SubProtocols = subProtocols;
-            return this;
-        }
-
-        public MqttClientWebSocketOptionsBuilder WithUri(string uri)
-        {
-            _webSocketOptions.Uri = uri;
-            return this;
-        }
-
-#if !NETSTANDARD1_3
-        public MqttClientWebSocketOptionsBuilder WithKeepAliveInterval(TimeSpan keepAliveInterval)
-        {
-            _webSocketOptions.KeepAliveInterval = keepAliveInterval;
-            return this;
-        }
-#endif
-#if !WINDOWS_UWP && !NETSTANDARD1_3
-        public MqttClientWebSocketOptionsBuilder WithUseDefaultCredentials(bool useDefaultCredentials = true)
-        {
-            _webSocketOptions.UseDefaultCredentials = useDefaultCredentials;
-            return this;
-        }
-#endif
-    }
-}

Source/MQTTnet/Client/Options/MqttClientWebSocketProxyOptionsBuilder.cs

@@ -1,67 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System.Collections.Generic;
-using System.Linq;
-
-namespace MQTTnet.Client
-{
-    public sealed class MqttClientWebSocketProxyOptionsBuilder
-    {
-        readonly MqttClientWebSocketProxyOptions _proxyOptions = new MqttClientWebSocketProxyOptions();
-
-        public MqttClientWebSocketProxyOptionsBuilder WithAddress(string address)
-        {
-            _proxyOptions.Address = address;
-            return this;
-        }
-        
-        public MqttClientWebSocketProxyOptionsBuilder WithUsername(string username)
-        {
-            _proxyOptions.Username = username;
-            return this;
-        }
-        
-        public MqttClientWebSocketProxyOptionsBuilder WithPassword(string password)
-        {
-            _proxyOptions.Password = password;
-            return this;
-        }
-        
-        public MqttClientWebSocketProxyOptionsBuilder WithDomain(string domain)
-        {
-            _proxyOptions.Domain = domain;
-            return this;
-        }
-        
-        public MqttClientWebSocketProxyOptionsBuilder WithBypassOnLocal(bool bypassOnLocal = true)
-        {
-            _proxyOptions.BypassOnLocal = bypassOnLocal;
-            return this;
-        }
-        
-        public MqttClientWebSocketProxyOptionsBuilder WithBypassList(string[] bypassList)
-        {
-            _proxyOptions.BypassList = bypassList;
-            return this;
-        }
-        
-        public MqttClientWebSocketProxyOptionsBuilder WithBypassList(IEnumerable<string> bypassList)
-        {
-            _proxyOptions.BypassList = bypassList?.ToArray();
-            return this;
-        }
-        
-        public MqttClientWebSocketProxyOptionsBuilder WithUseDefaultCredentials(bool useDefaultCredentials = true)
-        {
-            _proxyOptions.UseDefaultCredentials = useDefaultCredentials;
-            return this;
-        }
-        
-        public MqttClientWebSocketProxyOptions Build()
-        {
-            return _proxyOptions;
-        }
-    }
-}

Source/MQTTnet/Client/Receiving/MqttApplicationMessageReceivedEventArgs.cs

@@ -77,7 +77,7 @@ namespace MQTTnet.Client
 
         internal MqttPublishPacket PublishPacket { get; set; }
 
-        public Task AcknowledgeAsync(CancellationToken cancellationToken)
+        public Task AcknowledgeAsync(CancellationToken cancellationToken = default)
         {
             if (_acknowledgeHandler == null)
             {

Source/MQTTnet/Exceptions/MqttClientNotConnectedException.cs

@@ -1,19 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-
-namespace MQTTnet.Exceptions
-{
-    public class MqttClientNotConnectedException : MqttCommunicationException
-    {
-        public MqttClientNotConnectedException() : base("The MQTT client is not connected.")
-        {
-        }
-
-        public MqttClientNotConnectedException(Exception innerException) : base("The MQTT client is not connected.", innerException)
-        {
-        }
-    }
-}

Source/MQTTnet/Formatter/MqttDisconnectPacketFactory.cs

@@ -5,107 +5,45 @@
 using MQTTnet.Client;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
-using MQTTnet.Server;
-using MQTTnet.Server.Disconnecting;
 
 namespace MQTTnet.Formatter
 {
     public sealed class MqttDisconnectPacketFactory
     {
-        static readonly MqttDisconnectPacket DefaultNormalDisconnection = new MqttDisconnectPacket
+        readonly MqttDisconnectPacket _normalDisconnection = new MqttDisconnectPacket
         {
-            ReasonCode = MqttDisconnectReasonCode.NormalDisconnection,
-            UserProperties = null,
-            ReasonString = null,
-            ServerReference = null,
-            SessionExpiryInterval = 0
-        };
-
-        static readonly MqttDisconnectPacket DefaultServerShuttingDown = new MqttDisconnectPacket
-        {
-            ReasonCode = MqttDisconnectReasonCode.ServerShuttingDown,
-            UserProperties = null,
-            ReasonString = null,
-            ServerReference = null,
-            SessionExpiryInterval = 0
-        };
-
-        static readonly MqttDisconnectPacket DefaultUnspecifiedError = new MqttDisconnectPacket
-        {
-            ReasonCode = MqttDisconnectReasonCode.UnspecifiedError,
-            UserProperties = null,
-            ReasonString = null,
-            ServerReference = null,
-            SessionExpiryInterval = 0
+            ReasonCode = MqttDisconnectReasonCode.NormalDisconnection
         };
 
         public MqttDisconnectPacket Create(MqttDisconnectReasonCode reasonCode)
         {
             if (reasonCode == MqttDisconnectReasonCode.NormalDisconnection)
             {
-                return DefaultNormalDisconnection;
-            }
-
-            if (reasonCode == MqttDisconnectReasonCode.ServerShuttingDown)
-            {
-                return DefaultServerShuttingDown;
-            }
-
-            if (reasonCode == MqttDisconnectReasonCode.UnspecifiedError)
-            {
-                return DefaultUnspecifiedError;
+                return _normalDisconnection;
             }
 
             return new MqttDisconnectPacket
             {
-                ReasonCode = reasonCode,
-                UserProperties = null,
-                ReasonString = null,
-                ServerReference = null,
-                SessionExpiryInterval = 0
-            };
-        }
-
-        public MqttDisconnectPacket Create(MqttServerStopOptions serverStopOptions)
-        {
-            if (serverStopOptions == null)
-            {
-                return DefaultServerShuttingDown;
-            }
-
-            return Create(serverStopOptions.DefaultClientDisconnectOptions);
-        }
-
-        public MqttDisconnectPacket Create(MqttServerClientDisconnectOptions clientDisconnectOptions)
-        {
-            if (clientDisconnectOptions == null)
-            {
-                return DefaultNormalDisconnection;
-            }
-
-            return new MqttDisconnectPacket
-            {
-                ReasonCode = clientDisconnectOptions.ReasonCode,
-                UserProperties = clientDisconnectOptions.UserProperties,
-                ReasonString = clientDisconnectOptions.ReasonString,
-                ServerReference = clientDisconnectOptions.ServerReference,
-                SessionExpiryInterval = 0 // TODO: Not yet supported!
+                ReasonCode = reasonCode
             };
         }
 
         public MqttDisconnectPacket Create(MqttClientDisconnectOptions clientDisconnectOptions)
         {
+            var packet = new MqttDisconnectPacket();
+
             if (clientDisconnectOptions == null)
             {
-                return DefaultNormalDisconnection;
+                packet.ReasonCode = MqttDisconnectReasonCode.NormalDisconnection;
+            }
+            else
+            {
+                packet.ReasonCode = (MqttDisconnectReasonCode)clientDisconnectOptions.Reason;
+                packet.UserProperties = clientDisconnectOptions.UserProperties;
+                packet.SessionExpiryInterval = clientDisconnectOptions.SessionExpiryInterval;
             }
 
-            return new MqttDisconnectPacket
-            {
-                ReasonCode = (MqttDisconnectReasonCode)clientDisconnectOptions.Reason,
-                UserProperties = clientDisconnectOptions.UserProperties,
-                SessionExpiryInterval = clientDisconnectOptions.SessionExpiryInterval
-            };
+            return packet;
         }
     }
 }

Source/MQTTnet/Formatter/V5/MqttV5PacketDecoder.cs

@@ -68,12 +68,12 @@ namespace MQTTnet.Formatter.V5
 
         MqttPacket DecodeAuthPacket(ArraySegment<byte> body)
         {
+            ThrowIfBodyIsEmpty(body);
+
             _bufferReader.SetBuffer(body.Array, body.Offset, body.Count);
 
             var packet = new MqttAuthPacket();
 
-            // MQTT spec: The Reason Code and Property Length can be omitted if the Reason Code is 0x00 (Success) and there are no Properties.
-            // In this case the AUTH has a Remaining Length of 0.
             if (_bufferReader.EndOfStream)
             {
                 packet.ReasonCode = MqttAuthenticateReasonCode.Success;
@@ -220,7 +220,7 @@ namespace MQTTnet.Formatter.V5
             var packet = new MqttConnectPacket
             {
                 // If the Request Problem Information is absent, the value of 1 is used.
-                RequestProblemInformation = true
+                RequestProblemInformation = true 
             };
 
             var protocolName = _bufferReader.ReadString();
@@ -352,16 +352,7 @@ namespace MQTTnet.Formatter.V5
 
         MqttPacket DecodeDisconnectPacket(ArraySegment<byte> body)
         {
-            // From RFC: 3.14.2.1 Disconnect Reason Code
-            // Byte 1 in the Variable Header is the Disconnect Reason Code.
-            // If the Remaining Length is less than 1 the value of 0x00 (Normal disconnection) is used.
-            if (body.Count == 0)
-            {
-                return new MqttDisconnectPacket
-                {
-                    ReasonCode = MqttDisconnectReasonCode.NormalDisconnection
-                };
-            }
+            ThrowIfBodyIsEmpty(body);
 
             _bufferReader.SetBuffer(body.Array, body.Offset, body.Count);
 
@@ -395,7 +386,7 @@ namespace MQTTnet.Formatter.V5
 
             return packet;
         }
-
+        
         MqttPacket DecodePubAckPacket(ArraySegment<byte> body)
         {
             ThrowIfBodyIsEmpty(body);
@@ -733,7 +724,7 @@ namespace MQTTnet.Formatter.V5
             packet.UserProperties = propertiesReader.CollectedUserProperties;
 
             packet.ReasonCodes = new List<MqttUnsubscribeReasonCode>(_bufferReader.BytesLeft);
-
+            
             while (!_bufferReader.EndOfStream)
             {
                 var reasonCode = (MqttUnsubscribeReasonCode)_bufferReader.ReadByte();
@@ -779,4 +770,4 @@ namespace MQTTnet.Formatter.V5
             }
         }
     }
-}
+}

Source/MQTTnet/Formatter/V5/MqttV5PacketEncoder.cs

@@ -13,7 +13,7 @@ namespace MQTTnet.Formatter.V5
     public sealed class MqttV5PacketEncoder
     {
         const int FixedHeaderSize = 1;
-
+        
         readonly MqttBufferWriter _bufferWriter;
         readonly MqttV5PropertiesWriter _propertiesWriter = new MqttV5PropertiesWriter(new MqttBufferWriter(1024, 4096));
 
@@ -64,20 +64,13 @@ namespace MQTTnet.Formatter.V5
 
         byte EncodeAuthPacket(MqttAuthPacket packet)
         {
+            _bufferWriter.WriteByte((byte)packet.ReasonCode);
+
             _propertiesWriter.WriteAuthenticationMethod(packet.AuthenticationMethod);
             _propertiesWriter.WriteAuthenticationData(packet.AuthenticationData);
             _propertiesWriter.WriteReasonString(packet.ReasonString);
             _propertiesWriter.WriteUserProperties(packet.UserProperties);
 
-            // MQTT spec: The Reason Code and Property Length can be omitted if the Reason Code is 0x00 (Success) and there are no Properties.
-            // In this case the AUTH has a Remaining Length of 0.
-            if (packet.ReasonCode == MqttAuthenticateReasonCode.Success && _propertiesWriter.Length == 0)
-            {
-                return MqttBufferWriter.BuildFixedHeader(MqttControlPacketType.Auth);
-            }
-
-            _bufferWriter.WriteByte((byte)packet.ReasonCode);
-
             _propertiesWriter.WriteTo(_bufferWriter);
             _propertiesWriter.Reset();
 
@@ -286,7 +279,7 @@ namespace MQTTnet.Formatter.V5
             _propertiesWriter.WriteReasonString(packet.ReasonString);
             _propertiesWriter.WriteUserProperties(packet.UserProperties);
 
-            if (_propertiesWriter.Length > 0 || packet.ReasonCode != MqttPubAckReasonCode.Success)
+            if (_bufferWriter.Length > 0 || packet.ReasonCode != MqttPubAckReasonCode.Success)
             {
                 _bufferWriter.WriteByte((byte)packet.ReasonCode);
                 _propertiesWriter.WriteTo(_bufferWriter);
@@ -382,7 +375,7 @@ namespace MQTTnet.Formatter.V5
 
             _bufferWriter.WriteTwoByteInteger(packet.PacketIdentifier);
 
-            if (_propertiesWriter.Length > 0 || packet.ReasonCode != MqttPubRecReasonCode.Success)
+            if (_bufferWriter.Length > 0 || packet.ReasonCode != MqttPubRecReasonCode.Success)
             {
                 _bufferWriter.WriteByte((byte)packet.ReasonCode);
                 _propertiesWriter.WriteTo(_bufferWriter);
@@ -533,7 +526,7 @@ namespace MQTTnet.Formatter.V5
 
         static void ThrowIfPacketIdentifierIsInvalid(ushort packetIdentifier, MqttPacket packet)
         {
-            // SUBSCRIBE, UNSUBSCRIBE, and PUBLISH(in cases where QoS > 0) Control Packets MUST contain a non-zero 16 - bit Packet Identifier[MQTT - 2.3.1 - 1].
+            // SUBSCRIBE, UNSUBSCRIBE, and PUBLISH(in cases where QoS > 0) Control Packets MUST contain a non-zero 16 - bit Packet Identifier[MQTT - 2.3.1 - 1]. 
 
             if (packetIdentifier == 0)
             {
@@ -541,4 +534,4 @@ namespace MQTTnet.Formatter.V5
             }
         }
     }
-}
+}

Source/MQTTnet/Implementations/CrossPlatformSocket.cs

@@ -22,20 +22,20 @@ namespace MQTTnet.Implementations
 
         NetworkStream _networkStream;
 
-        public CrossPlatformSocket(AddressFamily addressFamily, ProtocolType protocolType)
+        public CrossPlatformSocket(AddressFamily addressFamily)
         {
-            _socket = new Socket(addressFamily, SocketType.Stream, protocolType);
+            _socket = new Socket(addressFamily, SocketType.Stream, ProtocolType.Tcp);
 
 #if !NET5_0_OR_GREATER
             _socketDisposeAction = _socket.Dispose;
 #endif
         }
 
-        public CrossPlatformSocket(ProtocolType protocolType)
+        public CrossPlatformSocket()
         {
             // Having this constructor is important because avoiding the address family as parameter
             // will make use of dual mode in the .net framework.
-            _socket = new Socket(SocketType.Stream, protocolType);
+            _socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
 
 #if !NET5_0_OR_GREATER
             _socketDisposeAction = _socket.Dispose;
@@ -142,14 +142,12 @@ namespace MQTTnet.Implementations
             set => _socket.SendTimeout = value;
         }
 
-        public async Task<CrossPlatformSocket> AcceptAsync(CancellationToken cancellationToken)
+        public async Task<CrossPlatformSocket> AcceptAsync()
         {
             try
             {
 #if NET452 || NET461
                 var clientSocket = await Task.Factory.FromAsync(_socket.BeginAccept, _socket.EndAccept, null).ConfigureAwait(false);
-#elif NET7_0_OR_GREATER
-                var clientSocket = await _socket.AcceptAsync(cancellationToken).ConfigureAwait(false);
 #else
                 var clientSocket = await _socket.AcceptAsync().ConfigureAwait(false);
 #endif
@@ -172,16 +170,11 @@ namespace MQTTnet.Implementations
             _socket.Bind(localEndPoint);
         }
 
-        public Task ConnectAsync(string host, int port, CancellationToken cancellationToken)
+        public async Task ConnectAsync(string host, int port, CancellationToken cancellationToken)
         {
-            return ConnectAsync(new DnsEndPoint(host, port), cancellationToken);
-        }
-
-        public async Task ConnectAsync(EndPoint endPoint, CancellationToken cancellationToken)
-        {
-            if (endPoint is null)
+            if (host is null)
             {
-                throw new ArgumentNullException(nameof(endPoint));
+                throw new ArgumentNullException(nameof(host));
             }
 
             cancellationToken.ThrowIfCancellationRequested();
@@ -198,34 +191,15 @@ namespace MQTTnet.Implementations
 #endif
 
 #if NET5_0_OR_GREATER
-                await _socket.ConnectAsync(endPoint, cancellationToken).ConfigureAwait(false);
+                await _socket.ConnectAsync(host, port, cancellationToken).ConfigureAwait(false);
 #else
                 // Workaround for: https://github.com/dotnet/corefx/issues/24430
                 using (cancellationToken.Register(_socketDisposeAction))
                 {
 #if NET452 || NET461
-                    // This is a fix for Mono which behaves differently than dotnet.
-                    // The connection will not be established when the DNS endpoint is used.
-                    if (endPoint is DnsEndPoint dns && dns.AddressFamily == AddressFamily.Unspecified)
-                    {
-                        await Task.Factory.FromAsync(_socket.BeginConnect, _socket.EndConnect, dns.Host, dns.Port, null).ConfigureAwait(false);
-                    }
-                    else
-                    {
-                        await Task.Factory.FromAsync(_socket.BeginConnect, _socket.EndConnect, endPoint, null).ConfigureAwait(false);
-                    }
+                    await Task.Factory.FromAsync(_socket.BeginConnect, _socket.EndConnect, host, port, null).ConfigureAwait(false);
 #else
-
-                    // This is a fix for Mono which behaves differently than dotnet.
-                    // The connection will not be established when the DNS endpoint is used.
-                    if (endPoint is DnsEndPoint dns && dns.AddressFamily == AddressFamily.Unspecified)
-                    {
-                        await _socket.ConnectAsync(dns.Host, dns.Port).ConfigureAwait(false);
-                    }
-                    else
-                    {
-                        await _socket.ConnectAsync(endPoint).ConfigureAwait(false);
-                    }
+                    await _socket.ConnectAsync(host, port).ConfigureAwait(false);
 #endif
                 }
 #endif
@@ -243,7 +217,7 @@ namespace MQTTnet.Implementations
                     throw new MqttCommunicationTimedOutException();
                 }
 
-                throw new MqttCommunicationException($"Error while connecting host '{endPoint}'.", socketException);
+                throw new MqttCommunicationException($"Error while connecting with host '{host}:{port}'.", socketException);
             }
             catch (ObjectDisposedException)
             {

Source/MQTTnet/Implementations/MqttTcpChannel.Uwp.cs

@@ -6,6 +6,8 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
+using System.Runtime.InteropServices.WindowsRuntime;
 using System.Security.Authentication;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading;
@@ -16,8 +18,6 @@ using Windows.Security.Cryptography.Certificates;
 using MQTTnet.Channel;
 using MQTTnet.Client;
 using MQTTnet.Server;
-using System.Runtime.InteropServices.WindowsRuntime;
-using System.Net;
 
 namespace MQTTnet.Implementations
 {
@@ -66,22 +66,9 @@ namespace MQTTnet.Implementations
                 _socket.Control.KeepAlive = true;
             }
 
-            string hostName;
-            string serviceName;
-
-            if (_options.RemoteEndpoint is DnsEndPoint dns)
-            {
-                hostName = dns.Host;
-                serviceName = dns.Port.ToString();
-            }
-            else
-            {
-                throw new NotSupportedException("UWP only supports a DNS endpoint.");
-            }
-
             if (_options.TlsOptions?.UseTls != true)
             {
-                await _socket.ConnectAsync(new HostName(hostName), serviceName).AsTask().ConfigureAwait(false);
+                await _socket.ConnectAsync(new HostName(_options.Server), _options.GetPort().ToString()).AsTask().ConfigureAwait(false);
             }
             else
             {
@@ -102,7 +89,7 @@ namespace MQTTnet.Implementations
                     socketProtectionLevel = SocketProtectionLevel.Tls10;
                 }
 
-                await _socket.ConnectAsync(new HostName(hostName), serviceName, socketProtectionLevel).AsTask().ConfigureAwait(false);
+                await _socket.ConnectAsync(new HostName(_options.Server), _options.GetPort().ToString(), socketProtectionLevel).AsTask().ConfigureAwait(false);
             }
 
             Endpoint = _socket.Information.RemoteAddress + ":" + _socket.Information.RemotePort;
@@ -139,19 +126,17 @@ namespace MQTTnet.Implementations
 
         private static Certificate LoadCertificate(IMqttClientChannelOptions options)
         {
-            var certificates = options.TlsOptions?.ClientCertificatesProvider?.GetCertificates();
-
-            if (certificates == null || certificates.Count == 0)
+            if (options.TlsOptions.Certificates == null || !options.TlsOptions.Certificates.Any())
             {
                 return null;
             }
 
-            if (certificates.Count > 1)
+            if (options.TlsOptions.Certificates.Count > 1)
             {
                 throw new NotSupportedException("Only one client certificate is supported when using 'uap10.0'.");
             }
 
-            return new Certificate(certificates[0].Export(X509ContentType.Cert).AsBuffer());
+            return new Certificate(options.TlsOptions.Certificates.First().AsBuffer());
         }
 
         private IEnumerable<ChainValidationResult> ResolveIgnorableServerCertificateErrors()

Source/MQTTnet/Implementations/MqttTcpChannel.cs

@@ -3,20 +3,18 @@
 // See the LICENSE file in the project root for more information.
 
 #if !WINDOWS_UWP
+using MQTTnet.Channel;
+using MQTTnet.Client;
+using MQTTnet.Exceptions;
 using System;
 using System.IO;
-using System.Net;
 using System.Net.Security;
 using System.Net.Sockets;
 using System.Runtime.ExceptionServices;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
-using MQTTnet.Channel;
-using MQTTnet.Client;
-using MQTTnet.Exceptions;
 using MQTTnet.Internal;
-using MQTTnet.Protocol;
 
 namespace MQTTnet.Implementations
 {
@@ -64,27 +62,22 @@ namespace MQTTnet.Implementations
             {
                 if (_tcpOptions.AddressFamily == AddressFamily.Unspecified)
                 {
-                    socket = new CrossPlatformSocket(_tcpOptions.ProtocolType);
+                    socket = new CrossPlatformSocket();
                 }
                 else
                 {
-                    socket = new CrossPlatformSocket(_tcpOptions.AddressFamily, _tcpOptions.ProtocolType);
+                    socket = new CrossPlatformSocket(_tcpOptions.AddressFamily);
                 }
 
                 if (_tcpOptions.LocalEndpoint != null)
                 {
                     socket.Bind(_tcpOptions.LocalEndpoint);
                 }
-
+                
                 socket.ReceiveBufferSize = _tcpOptions.BufferSize;
                 socket.SendBufferSize = _tcpOptions.BufferSize;
                 socket.SendTimeout = (int)_clientOptions.Timeout.TotalMilliseconds;
-
-                if (_tcpOptions.ProtocolType == ProtocolType.Tcp)
-                {
-                    // Other protocol types do not support the Nagle algorithm.
-                    socket.NoDelay = _tcpOptions.NoDelay;
-                }
+                socket.NoDelay = _tcpOptions.NoDelay;
 
                 if (socket.LingerState != null)
                 {
@@ -99,30 +92,7 @@ namespace MQTTnet.Implementations
                     socket.DualMode = _tcpOptions.DualMode.Value;
                 }
 
-                // This block is only for backward compatibility.
-                if (_tcpOptions.RemoteEndpoint == null && !string.IsNullOrEmpty(_tcpOptions.Server))
-                {
-                    int port;
-                    if (_tcpOptions.Port.HasValue)
-                    {
-                        port = _tcpOptions.Port.Value;
-                    }
-                    else
-                    {
-                        if (_tcpOptions.TlsOptions?.UseTls == true)
-                        {
-                            port = MqttPorts.Secure;
-                        }
-                        else
-                        {
-                            port = MqttPorts.Default;
-                        }
-                    }
-
-                    _tcpOptions.RemoteEndpoint = new DnsEndPoint(_tcpOptions.Server, port, AddressFamily.Unspecified);
-                }
-
-                await socket.ConnectAsync(_tcpOptions.RemoteEndpoint, cancellationToken).ConfigureAwait(false);
+                await socket.ConnectAsync(_tcpOptions.Server, _tcpOptions.GetPort(), cancellationToken).ConfigureAwait(false);
 
                 cancellationToken.ThrowIfCancellationRequested();
 
@@ -133,31 +103,10 @@ namespace MQTTnet.Implementations
                     var targetHost = _tcpOptions.TlsOptions.TargetHost;
                     if (string.IsNullOrEmpty(targetHost))
                     {
-                        if (_tcpOptions.RemoteEndpoint is DnsEndPoint dns)
-                        {
-                            targetHost = dns.Host;
-                        }
+                        targetHost = _tcpOptions.Server;
                     }
-
-                    SslStream sslStream;
-                    if (_tcpOptions.TlsOptions.CertificateSelectionHandler != null)
-                    {
-                        sslStream = new SslStream(
-                            networkStream,
-                            false,
-                            InternalUserCertificateValidationCallback,
-                            InternalUserCertificateSelectionCallback);
-                    }
-                    else
-                    {
-                        // Use a different constructor depending on the options for MQTTnet so that we do not have
-                        // to copy the exact same behavior of the selection handler.
-                        sslStream = new SslStream(
-                            networkStream,
-                            false,
-                            InternalUserCertificateValidationCallback);
-                    }
-
+                    
+                    var sslStream = new SslStream(networkStream, false, InternalUserCertificateValidationCallback);
                     try
                     {
 #if NETCOREAPP3_1_OR_GREATER
@@ -166,29 +115,14 @@ namespace MQTTnet.Implementations
                             ApplicationProtocols = _tcpOptions.TlsOptions.ApplicationProtocols,
                             ClientCertificates = LoadCertificates(),
                             EnabledSslProtocols = _tcpOptions.TlsOptions.SslProtocol,
-                            CertificateRevocationCheckMode = _tcpOptions.TlsOptions.IgnoreCertificateRevocationErrors
-                                ? X509RevocationMode.NoCheck
-                                : _tcpOptions.TlsOptions.RevocationMode,
+                            CertificateRevocationCheckMode =
+ _tcpOptions.TlsOptions.IgnoreCertificateRevocationErrors ? X509RevocationMode.NoCheck : _tcpOptions.TlsOptions.RevocationMode,
                             TargetHost = targetHost,
                             CipherSuitesPolicy = _tcpOptions.TlsOptions.CipherSuitesPolicy,
                             EncryptionPolicy = _tcpOptions.TlsOptions.EncryptionPolicy,
                             AllowRenegotiation = _tcpOptions.TlsOptions.AllowRenegotiation
                         };
 
-#if NET7_0_OR_GREATER
-                        if (_tcpOptions.TlsOptions.TrustChain?.Count > 0)
-                        {
-                            sslOptions.CertificateChainPolicy = new X509ChainPolicy
-                            {
-                                TrustMode = X509ChainTrustMode.CustomRootTrust,
-                                VerificationFlags = X509VerificationFlags.IgnoreEndRevocationUnknown,
-                                RevocationMode = _tcpOptions.TlsOptions.IgnoreCertificateRevocationErrors ? X509RevocationMode.NoCheck : _tcpOptions.TlsOptions.RevocationMode
-                            };
-
-                            sslOptions.CertificateChainPolicy.CustomTrustStore.AddRange(_tcpOptions.TlsOptions.TrustChain);
-                        }
-#endif
-
                         await sslStream.AuthenticateAsClientAsync(sslOptions, cancellationToken).ConfigureAwait(false);
 #else
                         await sslStream.AuthenticateAsClientAsync(
@@ -338,34 +272,19 @@ namespace MQTTnet.Implementations
             }
         }
 
-        X509Certificate InternalUserCertificateSelectionCallback(
-            object sender,
-            string targetHost,
-            X509CertificateCollection localCertificates,
-            X509Certificate remoteCertificate,
-            string[] acceptableIssuers)
-        {
-            var certificateSelectionHandler = _tcpOptions?.TlsOptions?.CertificateSelectionHandler;
-            if (certificateSelectionHandler != null)
-            {
-                var eventArgs = new MqttClientCertificateSelectionEventArgs(targetHost, localCertificates, remoteCertificate, acceptableIssuers, _tcpOptions);
-                return certificateSelectionHandler(eventArgs);
-            }
-
-            if (localCertificates?.Count > 0)
-            {
-                return localCertificates[0];
-            }
-
-            return null;
-        }
-
         bool InternalUserCertificateValidationCallback(object sender, X509Certificate x509Certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
         {
             var certificateValidationHandler = _tcpOptions?.TlsOptions?.CertificateValidationHandler;
             if (certificateValidationHandler != null)
             {
-                var eventArgs = new MqttClientCertificateValidationEventArgs(x509Certificate, chain, sslPolicyErrors, _tcpOptions);
+                var eventArgs = new MqttClientCertificateValidationEventArgs
+                {
+                    Certificate = x509Certificate,
+                    Chain = chain,
+                    SslPolicyErrors = sslPolicyErrors,
+                    ClientOptions = _tcpOptions
+                };
+
                 return certificateValidationHandler(eventArgs);
             }
 
@@ -379,7 +298,18 @@ namespace MQTTnet.Implementations
 
         X509CertificateCollection LoadCertificates()
         {
-            return _tcpOptions.TlsOptions.ClientCertificatesProvider?.GetCertificates();
+            if (_tcpOptions.TlsOptions.Certificates == null)
+            {
+                return null;
+            }
+
+            var certificates = new X509CertificateCollection();
+            foreach (var certificate in _tcpOptions.TlsOptions.Certificates)
+            {
+                certificates.Add(certificate);
+            }
+
+            return certificates;
         }
     }
 }

Source/MQTTnet/Implementations/MqttTcpServerListener.cs

@@ -27,7 +27,7 @@ namespace MQTTnet.Implementations
         readonly MqttServerOptions _serverOptions;
         readonly MqttServerTcpEndpointBaseOptions _options;
         readonly MqttServerTlsTcpEndpointOptions _tlsOptions;
-
+        
         CrossPlatformSocket _socket;
         IPEndPoint _localEndPoint;
 
@@ -65,7 +65,7 @@ namespace MQTTnet.Implementations
 
                 _logger.Info("Starting TCP listener (Endpoint={0}, TLS={1})", _localEndPoint, _tlsOptions?.CertificateProvider != null);
 
-                _socket = new CrossPlatformSocket(_addressFamily, ProtocolType.Tcp);
+                _socket = new CrossPlatformSocket(_addressFamily);
 
                 // Usage of socket options is described here: https://docs.microsoft.com/en-us/dotnet/api/system.net.sockets.socket.setsocketoption?view=netcore-2.2
                 if (_options.ReuseAddress)
@@ -87,33 +87,33 @@ namespace MQTTnet.Implementations
                 {
                     _socket.KeepAlive = _options.KeepAlive.Value;
                 }
-
+                
                 if (_options.TcpKeepAliveInterval.HasValue)
                 {
                     _socket.TcpKeepAliveInterval = _options.TcpKeepAliveInterval.Value;
                 }
-
+                
                 if (_options.TcpKeepAliveRetryCount.HasValue)
                 {
                     _socket.TcpKeepAliveInterval = _options.TcpKeepAliveRetryCount.Value;
                 }
-
+                
                 if (_options.TcpKeepAliveTime.HasValue)
                 {
                     _socket.TcpKeepAliveTime = _options.TcpKeepAliveTime.Value;
                 }
-
+                
                 _socket.Bind(_localEndPoint);
-
+                
                 // Get the local endpoint back from the socket. The port may have changed.
                 // This can happen when port 0 is used. Then the OS will choose the next free port.
                 _localEndPoint = (IPEndPoint)_socket.LocalEndPoint;
                 _options.Port = _localEndPoint.Port;
-
+                
                 _socket.Listen(_options.ConnectionBacklog);
-
+                
                 _logger.Verbose("TCP listener started (Endpoint={0})", _localEndPoint);
-
+                
                 Task.Run(() => AcceptClientConnectionsAsync(cancellationToken), cancellationToken).RunInBackground(_logger);
 
                 return true;
@@ -141,7 +141,7 @@ namespace MQTTnet.Implementations
             {
                 try
                 {
-                    var clientSocket = await _socket.AcceptAsync(cancellationToken).ConfigureAwait(false);
+                    var clientSocket = await _socket.AcceptAsync().ConfigureAwait(false);
                     if (clientSocket == null)
                     {
                         continue;
@@ -183,7 +183,7 @@ namespace MQTTnet.Implementations
                 clientSocket.NoDelay = _options.NoDelay;
                 stream = clientSocket.GetStream();
                 var clientCertificate = _tlsOptions?.CertificateProvider?.GetCertificate();
-
+                
                 if (clientCertificate != null)
                 {
                     if (!clientCertificate.HasPrivateKey)
@@ -228,7 +228,7 @@ namespace MQTTnet.Implementations
                     var tcpChannel = new MqttTcpChannel(stream, remoteEndPoint, clientCertificate);
                     var bufferWriter = new MqttBufferWriter(_serverOptions.WriterBufferSize, _serverOptions.WriterBufferSizeMax);
                     var packetFormatterAdapter = new MqttPacketFormatterAdapter(bufferWriter);
-
+                    
                     using (var clientAdapter = new MqttChannelAdapter(tcpChannel, packetFormatterAdapter, _rootLogger))
                     {
                         clientAdapter.AllowPacketFragmentation = _options.AllowPacketFragmentation;

Source/MQTTnet/Implementations/MqttWebSocketChannel.cs

@@ -46,13 +46,13 @@ namespace MQTTnet.Implementations
             var uri = _options.Uri;
             if (!uri.StartsWith("ws://", StringComparison.OrdinalIgnoreCase) && !uri.StartsWith("wss://", StringComparison.OrdinalIgnoreCase))
             {
-                if (_options.TlsOptions?.UseTls == true)
+                if (_options.TlsOptions?.UseTls == false)
                 {
-                    uri = "wss://" + uri;
+                    uri = "ws://" + uri;
                 }
                 else
                 {
-                    uri = "ws://" + uri;
+                    uri = "wss://" + uri;
                 }
             }
 
@@ -109,7 +109,7 @@ namespace MQTTnet.Implementations
             // A single WebSocket data frame can contain multiple or partial MQTT Control Packets. The receiver MUST NOT assume that MQTT Control Packets are aligned on WebSocket frame boundaries [MQTT-6.0.0-2].
             await _webSocket.SendAsync(buffer, WebSocketMessageType.Binary, isEndOfPacket, cancellationToken).ConfigureAwait(false);
 #else
-            // The lock is required because the client will throw an exception if _SendAsync_ is
+            // The lock is required because the client will throw an exception if _SendAsync_ is 
             // called from multiple threads at the same time. But this issue only happens with several
             // framework versions.
             if (_sendLock == null)
@@ -156,7 +156,7 @@ namespace MQTTnet.Implementations
 #else
             var proxyUri = new Uri(_options.ProxyOptions.Address);
             WebProxy webProxy;
-
+            
             if (!string.IsNullOrEmpty(_options.ProxyOptions.Username) && !string.IsNullOrEmpty(_options.ProxyOptions.Password))
             {
                 var credentials = new NetworkCredential(_options.ProxyOptions.Username, _options.ProxyOptions.Password, _options.ProxyOptions.Domain);
@@ -164,9 +164,9 @@ namespace MQTTnet.Implementations
             }
             else
             {
-                webProxy = new WebProxy(proxyUri, _options.ProxyOptions.BypassOnLocal, _options.ProxyOptions.BypassList);
+                webProxy = new WebProxy(proxyUri, _options.ProxyOptions.BypassOnLocal, _options.ProxyOptions.BypassList);    
             }
-
+            
             if (_options.ProxyOptions.UseDefaultCredentials)
             {
                 // Only update the property if required because setting it to false will alter
@@ -206,12 +206,16 @@ namespace MQTTnet.Implementations
                 clientWebSocket.Options.Cookies = _options.CookieContainer;
             }
 
-            if (_options.TlsOptions?.UseTls == true)
+            if (_options.TlsOptions?.UseTls == true && _options.TlsOptions?.Certificates != null)
             {
-                var certificates = _options.TlsOptions?.ClientCertificatesProvider?.GetCertificates();
-                if (certificates?.Count > 0)
+                clientWebSocket.Options.ClientCertificates = new X509CertificateCollection();
+                foreach (var certificate in _options.TlsOptions.Certificates)
                 {
-                    clientWebSocket.Options.ClientCertificates = certificates;
+#if WINDOWS_UWP
+                    clientWebSocket.Options.ClientCertificates.Add(new X509Certificate(certificate));
+#else
+                    clientWebSocket.Options.ClientCertificates.Add(certificate);
+#endif
                 }
             }
 
@@ -234,7 +238,7 @@ namespace MQTTnet.Implementations
             {
                 clientWebSocket.Options.Credentials = _options.Credentials;
             }
-
+            
             var certificateValidationHandler = _options.TlsOptions?.CertificateValidationHandler;
             if (certificateValidationHandler != null)
             {
@@ -244,31 +248,28 @@ namespace MQTTnet.Implementations
                 throw new NotSupportedException("Remote certificate validation callback is not supported when using 'netstandard2.0'.");
 #elif WINDOWS_UWP
                 throw new NotSupportedException("Remote certificate validation callback is not supported when using 'uap10.0'.");
-#elif NET452 || NET461 || NET48
-                ServicePointManager.ServerCertificateValidationCallback += (sender, certificate, chain, sslPolicyErrors) =>
-                {
-                    var context = new MqttClientCertificateValidationEventArgs(certificate, chain, sslPolicyErrors, _options)
-                    {
-                        Sender = sender
-                    };
-
-                    return certificateValidationHandler(context);
-                };
+#elif NET452
+                throw new NotSupportedException("Remote certificate validation callback is not supported when using 'net452'.");
+#elif NET461
+                throw new NotSupportedException("Remote certificate validation callback is not supported when using 'net461'.");
+#elif NET48
+                throw new NotSupportedException("Remote certificate validation callback is not supported when using 'net48'.");
 #else
                 clientWebSocket.Options.RemoteCertificateValidationCallback = (sender, certificate, chain, sslPolicyErrors) =>
                 {
                     // TODO: Find a way to add client options to same callback. Problem is that they have a different type.
-                    var context = new MqttClientCertificateValidationEventArgs(certificate, chain, sslPolicyErrors, _options);
+                    var context = new MqttClientCertificateValidationEventArgs
+                    {
+                        Certificate = certificate,
+                        Chain = chain,
+                        SslPolicyErrors = sslPolicyErrors,
+                        ClientOptions = _options
+                    };
+
                     return certificateValidationHandler(context);
                 };
 #endif
-
-                var certificateSelectionHandler = _options.TlsOptions?.CertificateSelectionHandler;
-                if (certificateSelectionHandler != null)
-                {
-                    throw new NotSupportedException("Remote certificate selection callback is not supported for WebSocket connections.");
-                }
             }
         }
     }
-}
+}

Source/MQTTnet/Internal/MqttPacketBus.cs

@@ -104,22 +104,17 @@ namespace MQTTnet.Internal
             _signal.Dispose();
         }
 
-        public MqttPacketBusItem DropFirstItem(MqttPacketBusPartition partition)
+        public void DropFirstItem(MqttPacketBusPartition partition)
         {
             lock (_syncRoot)
             {
                 var partitionInstance = _partitions[(int)partition];
 
-                if (partitionInstance.Count > 0)
+                if (partitionInstance.Any())
                 {
-                    var firstItem = partitionInstance.First.Value;
                     partitionInstance.RemoveFirst();
-
-                    return firstItem;
                 }
             }
-
-            return null;
         }
 
         public void EnqueueItem(MqttPacketBusItem item, MqttPacketBusPartition partition)

Source/MQTTnet/LowLevelClient/LowLevelMqttClient.cs

@@ -19,6 +19,7 @@ namespace MQTTnet.LowLevelClient
         readonly IMqttClientAdapterFactory _clientAdapterFactory;
         readonly AsyncEvent<InspectMqttPacketEventArgs> _inspectPacketEvent = new AsyncEvent<InspectMqttPacketEventArgs>();
         readonly MqttNetSourceLogger _logger;
+
         readonly IMqttNetLogger _rootLogger;
 
         IMqttChannelAdapter _adapter;

Source/MQTTnet/MQTTnet.csproj.DotSettings

@@ -17,5 +17,4 @@
 	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=server_005Cmanagement/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=server_005Coptions/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=server_005Cstatus/@EntryIndexedValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=server_005Cstopping/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=server_005Cstorage/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>

Source/MQTTnet/MqttFactory.cs

@@ -11,7 +11,6 @@ using MQTTnet.Diagnostics;
 using MQTTnet.Implementations;
 using MQTTnet.LowLevelClient;
 using MQTTnet.Server;
-using MQTTnet.Server.Disconnecting;
 using MqttClient = MQTTnet.Client.MqttClient;
 
 namespace MQTTnet
@@ -135,11 +134,6 @@ namespace MQTTnet
             return new MqttClient(clientAdapterFactory, logger);
         }
 
-        public MqttExtendedAuthenticationExchangeOptionsFactory CreateMqttExtendedAuthenticationExchangeOptionsBuilder()
-        {
-            return new MqttExtendedAuthenticationExchangeOptionsFactory();
-        }
-
         public MqttServer CreateMqttServer(MqttServerOptions options)
         {
             return CreateMqttServer(options, DefaultLogger);
@@ -181,16 +175,6 @@ namespace MQTTnet
             return new MqttServer(options, serverAdapters, DefaultLogger);
         }
 
-        public MqttServerClientDisconnectOptionsBuilder CreateMqttServerClientDisconnectOptionsBuilder()
-        {
-            return new MqttServerClientDisconnectOptionsBuilder();
-        }
-
-        public MqttServerStopOptionsBuilder CreateMqttServerStopOptionsBuilder()
-        {
-            return new MqttServerStopOptionsBuilder();
-        }
-
         public MqttServerOptionsBuilder CreateServerOptionsBuilder()
         {
             return new MqttServerOptionsBuilder();

Source/MQTTnet/Protocol/MqttPorts.cs

@@ -1,13 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-namespace MQTTnet.Protocol
-{
-    public static class MqttPorts
-    {
-        public const int Default = 1883;
-
-        public const int Secure = 8883;
-    }
-}

Source/MQTTnet/Server/Disconnecting/MqttServerClientDisconnectOptions.cs

@@ -1,33 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System.Collections.Generic;
-using MQTTnet.Packets;
-using MQTTnet.Protocol;
-
-namespace MQTTnet.Server.Disconnecting
-{
-    public sealed class MqttServerClientDisconnectOptions
-    {
-        public MqttDisconnectReasonCode ReasonCode { get; set; } = MqttDisconnectReasonCode.NormalDisconnection;
-
-        /// <summary>
-        ///     The reason string is sent to every client via a DISCONNECT packet.
-        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
-        /// </summary>
-        public string ReasonString { get; set; }
-
-        /// <summary>
-        ///     The server reference is sent to every client via a DISCONNECT packet.
-        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
-        /// </summary>
-        public string ServerReference { get; set; }
-
-        /// <summary>
-        ///     These user properties are sent to every client via a DISCONNECT packet.
-        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
-        /// </summary>
-        public List<MqttUserProperty> UserProperties { get; set; }
-    }
-}

Source/MQTTnet/Server/Disconnecting/MqttServerClientDisconnectOptionsBuilder.cs

@@ -1,55 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System.Collections.Generic;
-using MQTTnet.Packets;
-using MQTTnet.Protocol;
-
-namespace MQTTnet.Server.Disconnecting
-{
-    public sealed class MqttServerClientDisconnectOptionsBuilder
-    {
-        readonly MqttServerClientDisconnectOptions _options = new MqttServerClientDisconnectOptions();
-
-        public MqttServerClientDisconnectOptions Build()
-        {
-            return _options;
-        }
-
-        public MqttServerClientDisconnectOptionsBuilder WithReasonCode(MqttDisconnectReasonCode value)
-        {
-            _options.ReasonCode = value;
-            return this;
-        }
-
-        public MqttServerClientDisconnectOptionsBuilder WithReasonString(string value)
-        {
-            _options.ReasonString = value;
-            return this;
-        }
-
-        public MqttServerClientDisconnectOptionsBuilder WithServerReference(string value)
-        {
-            _options.ServerReference = value;
-            return this;
-        }
-
-        public MqttServerClientDisconnectOptionsBuilder WithUserProperties(List<MqttUserProperty> value)
-        {
-            _options.UserProperties = value;
-            return this;
-        }
-
-        public MqttServerClientDisconnectOptionsBuilder WithUserProperty(string name, string value)
-        {
-            if (_options.UserProperties == null)
-            {
-                _options.UserProperties = new List<MqttUserProperty>();
-            }
-
-            _options.UserProperties.Add(new MqttUserProperty(name, value));
-            return this;
-        }
-    }
-}