Merge from master.

Build/MQTTnet.AspNetCore.nuspec

@@ -10,7 +10,8 @@
     <iconUrl>https://raw.githubusercontent.com/chkr1011/MQTTnet/master/Images/Logo_128x128.png</iconUrl>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>This is a support library to integrate MQTTnet into AspNetCore.</description>
-    <releaseNotes>* For more release notes please check the MQTTnet release notes.
+    <releaseNotes> * For more release notes please check the MQTTnet release notes.
+ * [Server] fixed cpu spike in case a client disconnectes (issue 421)
     </releaseNotes>
     <copyright>Copyright Christian Kratky 2016-2018</copyright>
     <tags>MQTT Message Queue Telemetry Transport MQTTClient MQTTServer Server MQTTBroker Broker NETStandard IoT InternetOfThings Messaging Hardware Arduino Sensor Actuator M2M ESP Smart Home Cities Automation Xamarin</tags>

Source/MQTTnet.AspnetCore/MqttConnectionContext.cs

@@ -1,6 +1,7 @@
 using Microsoft.AspNetCore.Connections;
 using MQTTnet.Adapter;
 using MQTTnet.AspNetCore.Client.Tcp;
+using MQTTnet.Exceptions;
 using MQTTnet.Packets;
 using MQTTnet.Serializer;
 using System;
@@ -83,7 +84,7 @@ namespace MQTTnet.AspNetCore
                         }
                         else if (readResult.IsCompleted)
                         {
-                            break;
+                            throw new MqttCommunicationException("Connection Aborted");
                         }
                     }
                     finally

Source/MQTTnet/Implementations/MqttTcpServerListener.cs

@@ -20,8 +20,8 @@ namespace MQTTnet.Implementations
         private readonly CancellationToken _cancellationToken;
         private readonly AddressFamily _addressFamily;
         private readonly MqttServerTcpEndpointBaseOptions _options;
+        private readonly MqttServerTlsTcpEndpointOptions _tlsOptions;
         private readonly X509Certificate2 _tlsCertificate;
-
         private Socket _socket;
 
         public MqttTcpServerListener(
@@ -36,6 +36,11 @@ namespace MQTTnet.Implementations
             _tlsCertificate = tlsCertificate;
             _cancellationToken = cancellationToken;
             _logger = logger.CreateChildLogger(nameof(MqttTcpServerListener));
+            
+            if (_options is MqttServerTlsTcpEndpointOptions tlsOptions)
+            {
+                _tlsOptions = tlsOptions;
+            }
         }
 
         public event EventHandler<MqttServerAdapterClientAcceptedEventArgs> ClientAccepted;
@@ -75,7 +80,7 @@ namespace MQTTnet.Implementations
                     if (_tlsCertificate != null)
                     {
                         sslStream = new SslStream(new NetworkStream(clientSocket), false);
-                        await sslStream.AuthenticateAsServerAsync(_tlsCertificate, false, SslProtocols.Tls12, false).ConfigureAwait(false);
+                        await sslStream.AuthenticateAsServerAsync(_tlsCertificate, false, _tlsOptions.SslProtocol, false).ConfigureAwait(false);
                     }
 
                     _logger.Verbose("Client '{0}' accepted by TCP listener '{1}, {2}'.",

Source/MQTTnet/Server/MqttServerOptionsBuilder.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Net;
+using System.Security.Authentication;
 
 namespace MQTTnet.Server
 {
@@ -80,6 +81,12 @@ namespace MQTTnet.Server
             return this;
         }
 
+        public MqttServerOptionsBuilder WithEncryptionSslProtocol(SslProtocols value)
+        {
+            _options.TlsEndpointOptions.SslProtocol = value;
+            return this;
+        }
+
         public MqttServerOptionsBuilder WithoutEncryptedEndpoint()
         {
             _options.TlsEndpointOptions.IsEnabled = false;

Source/MQTTnet/Server/MqttServerTlsTcpEndpointOptions.cs

@@ -1,4 +1,6 @@
-namespace MQTTnet.Server
+using System.Security.Authentication;
+
+namespace MQTTnet.Server
 {
     public class MqttServerTlsTcpEndpointOptions : MqttServerTcpEndpointBaseOptions
     {
@@ -8,5 +10,8 @@
         }
 
         public byte[] Certificate { get; set; }
+
+
+        public SslProtocols SslProtocol { get; set; } = SslProtocols.Tls12;
     }
 }

Tests/MQTTnet.AspNetCore.Tests/MQTTnet.AspNetCore.Tests.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>netcoreapp2.1</TargetFramework>

Tests/MQTTnet.AspNetCore.Tests/Mockups/ConnectionContextMockup.cs

@@ -0,0 +1,22 @@
+using System.Collections.Generic;
+using System.IO.Pipelines;
+using Microsoft.AspNetCore.Connections;
+using Microsoft.AspNetCore.Http.Features;
+
+namespace MQTTnet.AspNetCore.Tests.Mockups
+{
+    public class ConnectionContextMockup : ConnectionContext
+    {
+        public override string ConnectionId { get; set; }
+
+        public override IFeatureCollection Features { get; }
+
+        public override IDictionary<object, object> Items { get; set; }
+        public override IDuplexPipe Transport { get; set; }
+
+        public ConnectionContextMockup()
+        {
+            //Transport = new DefaultConnectionContext
+        }
+    }
+}

Tests/MQTTnet.AspNetCore.Tests/Mockups/DuplexPipeMockup.cs

@@ -0,0 +1,16 @@
+using System.IO.Pipelines;
+
+namespace MQTTnet.AspNetCore.Tests.Mockups
+{
+    public class DuplexPipeMockup : IDuplexPipe
+    {
+        PipeReader IDuplexPipe.Input => Receive.Reader;
+
+        PipeWriter IDuplexPipe.Output => Send.Writer;
+
+
+        public Pipe Receive { get; set; } = new Pipe();
+
+        public Pipe Send { get; set; } = new Pipe();
+    }
+}

Tests/MQTTnet.AspNetCore.Tests/MqttConnectionContextTest.cs

@@ -0,0 +1,29 @@
+using Microsoft.AspNetCore.Connections;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using MQTTnet.AspNetCore.Tests.Mockups;
+using MQTTnet.Exceptions;
+using MQTTnet.Serializer;
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MQTTnet.AspNetCore.Tests
+{
+    [TestClass]
+    public class MqttConnectionContextTest
+    {
+        [TestMethod]
+        public async Task TestReceivePacketAsyncThrowsWhenReaderCompleted()
+        {
+            var serializer = new MqttPacketSerializer {};
+            var pipe = new DuplexPipeMockup();
+            var connection = new DefaultConnectionContext();
+            connection.Transport = pipe;
+            var ctx = new MqttConnectionContext(serializer, connection);
+
+            pipe.Receive.Writer.Complete();
+
+            await Assert.ThrowsExceptionAsync<MqttCommunicationException>(() => ctx.ReceivePacketAsync(TimeSpan.FromSeconds(1), CancellationToken.None));
+        }
+    }
+}