Code cleanup

Source/MQTTnet/Implementations/MqttTcpServerAdapter.cs

 // 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.
-
 #if !WINDOWS_UWP
-using MQTTnet.Adapter;
-using MQTTnet.Diagnostics;
-using MQTTnet.Server;
 using System;
 using System.Collections.Generic;
 using System.Net;
 using System.Net.Sockets;
-using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
+using MQTTnet.Adapter;
+using MQTTnet.Diagnostics;
 using MQTTnet.Internal;
-using MQTTnet.Certificates;
+using MQTTnet.Server;
 
 namespace MQTTnet.Implementations
 {
     public sealed class MqttTcpServerAdapter : IMqttServerAdapter
     {
         readonly List<MqttTcpServerListener> _listeners = new List<MqttTcpServerListener>();
+        
+        CancellationTokenSource _cancellationTokenSource;
 
         MqttServerOptions _serverOptions;
-        CancellationTokenSource _cancellationTokenSource;
-        
+
         public Func<IMqttChannelAdapter, Task> ClientHandler { get; set; }
 
         public bool TreatSocketOpeningErrorAsWarning { get; set; }
 
+        public void Dispose()
+        {
+            Cleanup();
+        }
+
         public Task StartAsync(MqttServerOptions options, IMqttNetLogger logger)
         {
-            if (_cancellationTokenSource != null) throw new InvalidOperationException("Server is already started.");
+            if (_cancellationTokenSource != null)
+            {
+                throw new InvalidOperationException("Server is already started.");
+            }
 
             _serverOptions = options;
-            
+
             _cancellationTokenSource = new CancellationTokenSource();
 
             if (options.DefaultEndpointOptions.IsEnabled)
@@ -61,11 +67,6 @@ namespace MQTTnet.Implementations
             return CompletedTask.Instance;
         }
 
-        public void Dispose()
-        {
-            Cleanup();
-        }
-
         void Cleanup()
         {
             try
@@ -86,9 +87,19 @@ namespace MQTTnet.Implementations
             }
         }
 
-        void RegisterListeners(MqttServerTcpEndpointBaseOptions tcpEndpointOptions, IMqttNetLogger logger, CancellationToken cancellationToken)
+        Task OnClientAcceptedAsync(IMqttChannelAdapter channelAdapter)
         {
+            var clientHandler = ClientHandler;
+            if (clientHandler == null)
+            {
+                return CompletedTask.Instance;
+            }
+
+            return clientHandler(channelAdapter);
+        }
 
+        void RegisterListeners(MqttServerTcpEndpointBaseOptions tcpEndpointOptions, IMqttNetLogger logger, CancellationToken cancellationToken)
+        {
             if (!tcpEndpointOptions.BoundInterNetworkAddress.Equals(IPAddress.None))
             {
                 var listenerV4 = new MqttTcpServerListener(AddressFamily.InterNetwork, _serverOptions, tcpEndpointOptions, logger)
@@ -115,17 +126,6 @@ namespace MQTTnet.Implementations
                 }
             }
         }
-
-        Task OnClientAcceptedAsync(IMqttChannelAdapter channelAdapter)
-        {
-            var clientHandler = ClientHandler;
-            if (clientHandler == null)
-            {
-                return CompletedTask.Instance;
-            }
-
-            return clientHandler(channelAdapter);
-        }
     }
 }
 #endif
\ No newline at end of file

Source/MQTTnet/Implementations/MqttTcpServerListener.cs

@@ -4,7 +4,6 @@
 
 #if !WINDOWS_UWP
 using MQTTnet.Adapter;
-using MQTTnet.Certificates;
 using MQTTnet.Diagnostics;
 using MQTTnet.Formatter;
 using MQTTnet.Internal;
@@ -28,8 +27,7 @@ namespace MQTTnet.Implementations
         readonly MqttServerOptions _serverOptions;
         readonly MqttServerTcpEndpointBaseOptions _options;
         readonly MqttServerTlsTcpEndpointOptions _tlsOptions;
-        X509Certificate2 _tlsCertificate;
-
+        
         CrossPlatformSocket _socket;
         IPEndPoint _localEndPoint;
 
@@ -48,7 +46,6 @@ namespace MQTTnet.Implementations
             if (_options is MqttServerTlsTcpEndpointOptions tlsOptions)
             {
                 _tlsOptions = tlsOptions;
-                _tlsCertificate = _tlsOptions.CertificateProvider.GetCertificate();
             }
         }
 
@@ -66,7 +63,7 @@ namespace MQTTnet.Implementations
 
                 _localEndPoint = new IPEndPoint(boundIp, _options.Port);
 
-                _logger.Info("Starting TCP listener (Endpoint='{0}', TLS={1}).", _localEndPoint, _tlsCertificate != null);
+                _logger.Info("Starting TCP listener (Endpoint={0}, TLS={1})", _localEndPoint, _tlsOptions?.CertificateProvider != null);
 
                 _socket = new CrossPlatformSocket(_addressFamily);
 
@@ -115,7 +112,7 @@ namespace MQTTnet.Implementations
                 
                 _socket.Listen(_options.ConnectionBacklog);
                 
-                _logger.Verbose("TCP listener started (Endpoint='{0}'.", _localEndPoint);
+                _logger.Verbose("TCP listener started (Endpoint={0})", _localEndPoint);
                 
                 Task.Run(() => AcceptClientConnectionsAsync(cancellationToken), cancellationToken).RunInBackground(_logger);
 
@@ -128,7 +125,7 @@ namespace MQTTnet.Implementations
                     throw;
                 }
 
-                _logger.Warning(exception, "Error while creating listener socket for local end point '{0}'.", _localEndPoint);
+                _logger.Warning(exception, "Error while starting TCP listener (Endpoint={0})", _localEndPoint);
                 return false;
             }
         }
@@ -136,10 +133,6 @@ namespace MQTTnet.Implementations
         public void Dispose()
         {
             _socket?.Dispose();
-
-#if !NET452
-            _tlsCertificate?.Dispose();
-#endif
         }
 
         async Task AcceptClientConnectionsAsync(CancellationToken cancellationToken)
@@ -170,7 +163,7 @@ namespace MQTTnet.Implementations
                         }
                     }
 
-                    _logger.Error(exception, "Error while accepting connection at TCP listener {0} TLS={1}.", _localEndPoint, _tlsCertificate != null);
+                    _logger.Error(exception, "Error while accepting TCP connection (Endpoint={0})", _localEndPoint);
                     await Task.Delay(TimeSpan.FromSeconds(1), cancellationToken).ConfigureAwait(false);
                 }
             }
@@ -185,31 +178,15 @@ namespace MQTTnet.Implementations
             {
                 remoteEndPoint = clientSocket.RemoteEndPoint.ToString();
 
-                _logger.Verbose("Client '{0}' accepted by TCP listener '{1}, {2}'.",
-                    remoteEndPoint,
-                    _localEndPoint,
-                    _addressFamily == AddressFamily.InterNetwork ? "ipv4" : "ipv6");
+                _logger.Verbose("TCP client '{0}' accepted (Local endpoint={1})", remoteEndPoint, _localEndPoint);
 
                 clientSocket.NoDelay = _options.NoDelay;
                 stream = clientSocket.GetStream();
-                X509Certificate2 clientCertificate = null;
-
-                if (_tlsOptions.CertificateProvider != null)
-                {
-                    var tlsCertificate = _tlsOptions.CertificateProvider.GetCertificate();
-                    if (tlsCertificate != _tlsCertificate)
-                    {
-                        var oldTlsCertificate = _tlsCertificate;
-                        _tlsCertificate = tlsCertificate;
-#if !NET452
-                        oldTlsCertificate.Dispose();
-#endif
-                    }
-                }
-
-                if (_tlsCertificate != null)
+                var clientCertificate = _tlsOptions?.CertificateProvider?.GetCertificate();
+                
+                if (clientCertificate != null)
                 {
-                    if (!_tlsCertificate.HasPrivateKey)
+                    if (!clientCertificate.HasPrivateKey)
                     {
                         throw new InvalidOperationException("The certificate for TLS encryption must contain the private key.");
                     }
@@ -218,9 +195,9 @@ namespace MQTTnet.Implementations
 
                     #if NETCOREAPP3_1_OR_GREATER
                         await sslStream.AuthenticateAsServerAsync(
-                            new SslServerAuthenticationOptions()
+                            new SslServerAuthenticationOptions
                             {
-                                ServerCertificate = _tlsCertificate,
+                                ServerCertificate = clientCertificate,
                                 ClientCertificateRequired = _tlsOptions.ClientCertificateRequired,
                                 EnabledSslProtocols = _tlsOptions.SslProtocol,
                                 CertificateRevocationCheckMode = _tlsOptions.CheckCertificateRevocation ? X509RevocationMode.Online : X509RevocationMode.NoCheck,
@@ -229,7 +206,7 @@ namespace MQTTnet.Implementations
                             }).ConfigureAwait(false);
                     #else
                         await sslStream.AuthenticateAsServerAsync(
-                            _tlsCertificate,
+                            clientCertificate,
                             _tlsOptions.ClientCertificateRequired,
                             _tlsOptions.SslProtocol,
                             _tlsOptions.CheckCertificateRevocation).ConfigureAwait(false);
@@ -272,7 +249,7 @@ namespace MQTTnet.Implementations
                     return;
                 }
 
-                _logger.Error(exception, "Error while handling client connection.");
+                _logger.Error(exception, "Error while handling TCP client connection");
             }
             finally
             {
@@ -287,10 +264,7 @@ namespace MQTTnet.Implementations
                 }
             }
 
-            _logger.Verbose("Client '{0}' disconnected at TCP listener '{1}, {2}'.",
-                remoteEndPoint,
-                _localEndPoint,
-                _addressFamily == AddressFamily.InterNetwork ? "ipv4" : "ipv6");
+            _logger.Verbose("TCP client '{0}' disconnected (Local endpoint={1})", remoteEndPoint, _localEndPoint);
         }
     }
 }

Source/MQTTnet/Server/Internal/MqttClientSubscriptionsManager.cs

@@ -407,13 +407,13 @@ namespace MQTTnet.Server
             {
                 // This is a MQTT V5+ feature.
                 return;
-                }
+            }
 
             if (createSubscriptionResult.Subscription.RetainHandling == MqttRetainHandling.SendAtSubscribeIfNewSubscriptionOnly && !createSubscriptionResult.IsNewSubscription)
-                {
-                    // This is a MQTT V5+ feature.
+            {
+                // This is a MQTT V5+ feature.
                 return;
-                }
+            }
 
             for (var index = retainedMessages.Count - 1; index >= 0; index--)
             {