Remove package suffix for final release version

Fix support for enhanced authentication (#2132 )
* Implement enhanced authentication for client and server. * Update samples * Add abstraction layer * Merge master * Use dedicated class for public API. * Update release notes * Rename methods to fit naming scheme * Fix unit tests and samples
2026-10-19 19:13:11 +08:00 · 2024-12-30 11:54:00 +01:00 · 2024-12-25 14:17:20 +01:00 · 2024-12-23 12:17:00 +01:00 · 2024-12-23 12:05:09 +01:00 · 2024-12-23 11:21:46 +01:00
134 changed files with 1815 additions and 1784 deletions
@@ -4,7 +4,7 @@ on: [push, pull_request]
 env:
  VERSION: "5.0.0.${{github.run_number}}"
-  PACKAGE_SUFFIX: "-RC"
+  PACKAGE_SUFFIX: ""
 jobs:
  build:
@@ -107,7 +107,8 @@ jobs:
        run: dotnet nuget push ${{ github.workspace }}/nugets/**/*.nupkg -k ${{ secrets.MYGET_API_KEY }} -s https://www.myget.org/F/mqttnet/api/v3/index.json --skip-duplicate
  publish-nuget:
-    if: ${{ github.event_name == 'published' }}
+    # Tag schema is 'v5.0.0-rc' etc.
    if: startsWith(github.ref, 'refs/tags/v')
    needs: [sign, test]
    runs-on: ubuntu-latest
@@ -8,431 +8,17 @@
 using System.Security.Authentication;
 using System.Security.Cryptography.X509Certificates;
 using System.Text;
 using MQTTnet.Formatter;
 using MQTTnet.Protocol;
 using MQTTnet.Samples.Helpers;
 using MQTTnet.Server;
 using MQTTnet.Server.EnhancedAuthentication;
 namespace MQTTnet.Samples.Client;
 public static class Client_Connection_Samples
 {
    public static async Task Clean_Disconnect()
    {
        /*
         * This sample disconnects in a clean way. This will send a MQTT DISCONNECT packet
         * to the server and close the connection afterwards.
         *
         * See sample _Connect_Client_ for more details.
         */
        var mqttFactory = new MqttClientFactory();
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
            // This will send the DISCONNECT packet. Calling _Dispose_ without DisconnectAsync the
            // connection is closed in a "not clean" way. See MQTT specification for more details.
            await mqttClient.DisconnectAsync(new MqttClientDisconnectOptionsBuilder().WithReason(MqttClientDisconnectOptionsReason.NormalDisconnection).Build());
        }
    }
    public static async Task Connect_Client()
    {
        /*
         * This sample creates a simple MQTT client and connects to a public broker.
         *
         * Always dispose the client when it is no longer used.
         * The default version of MQTT is 3.1.1.
         */
        var mqttFactory = new MqttClientFactory();
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            // Use builder classes where possible in this project.
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
            // This will throw an exception if the server is not available.
            // The result from this message returns additional data which was sent
            // from the server. Please refer to the MQTT protocol specification for details.
            var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
            Console.WriteLine("The MQTT client is connected.");
            response.DumpToConsole();
            // Send a clean disconnect to the server by calling _DisconnectAsync_. Without this the TCP connection
            // gets dropped and the server will handle this as a non clean disconnect (see MQTT spec for details).
            var mqttClientDisconnectOptions = mqttFactory.CreateClientDisconnectOptionsBuilder().Build();
            await mqttClient.DisconnectAsync(mqttClientDisconnectOptions, CancellationToken.None);
        }
    }
    public static async Task Connect_Client_Timeout()
    {
        /*
         * This sample creates a simple MQTT client and connects to an invalid broker using a timeout.
         *
         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
         */
        var mqttFactory = new MqttClientFactory();
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1").Build();
            try
            {
                using (var timeoutToken = new CancellationTokenSource(TimeSpan.FromSeconds(1)))
                {
                    await mqttClient.ConnectAsync(mqttClientOptions, timeoutToken.Token);
                }
            }
            catch (OperationCanceledException)
            {
                Console.WriteLine("Timeout while connecting.");
            }
        }
    }
    public static async Task Connect_Client_Using_MQTTv5()
    {
        /*
         * This sample creates a simple MQTT client and connects to a public broker using MQTTv5.
         *
         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
         */
        var mqttFactory = new MqttClientFactory();
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").WithProtocolVersion(MqttProtocolVersion.V500).Build();
            // In MQTTv5 the response contains much more information.
            var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
            Console.WriteLine("The MQTT client is connected.");
            response.DumpToConsole();
        }
    }
    public static async Task Connect_Client_Using_TLS_1_2()
    {
        /*
         * This sample creates a simple MQTT client and connects to a public broker using TLS 1.2 encryption.
         *
         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
         */
        var mqttFactory = new MqttClientFactory();
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("mqtt.fluux.io")
                .WithTlsOptions(
                    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);
                        // The default value is determined by the OS. Set manually to force version.
                        o.WithSslProtocols(SslProtocols.Tls12);
                    })
                .Build();
            using (var timeout = new CancellationTokenSource(5000))
            {
                await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
                Console.WriteLine("The MQTT client is connected.");
            }
        }
    }
    public static async Task Connect_Client_Using_WebSockets()
    {
        /*
         * This sample creates a simple MQTT client and connects to a public broker using a WebSocket connection.
         *
         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
         */
        var mqttFactory = new MqttClientFactory();
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.hivemq.com:8000/mqtt")).Build();
            var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
            Console.WriteLine("The MQTT client is connected.");
            response.DumpToConsole();
        }
    }
    public static async Task Connect_Client_With_TLS_Encryption()
    {
        /*
         * This sample creates a simple MQTT client and connects to a public broker with enabled TLS encryption.
         *
         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
         */
        var mqttFactory = new MqttClientFactory();
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8883)
                .WithTlsOptions(
                    o => o.WithCertificateValidationHandler(
                        // The used public broker sometimes has invalid certificates. This sample accepts all
                        // certificates. This should not be used in live environments.
                        _ => true))
                .Build();
            // In MQTTv5 the response contains much more information.
            using (var timeout = new CancellationTokenSource(5000))
            {
                var response = await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
                Console.WriteLine("The MQTT client is connected.");
                response.DumpToConsole();
            }
        }
    }
    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 MqttClientFactory();
        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()
    {
        /*
         * This sample disconnects from the server with sending a DISCONNECT packet.
         * This way of disconnecting is treated as a clean disconnect which will not
         * trigger sending the last will etc.
         */
        var mqttFactory = new MqttClientFactory();
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
            // Calling _DisconnectAsync_ will send a DISCONNECT packet before closing the connection.
            // Using a reason code requires MQTT version 5.0.0!
            await mqttClient.DisconnectAsync(MqttClientDisconnectOptionsReason.ImplementationSpecificError);
        }
    }
    public static async Task Disconnect_Non_Clean()
    {
        /*
         * This sample disconnects from the server without sending a DISCONNECT packet.
         * This way of disconnecting is treated as a non clean disconnect which will
         * trigger sending the last will etc.
         */
        var mqttFactory = new MqttClientFactory();
        var mqttClient = mqttFactory.CreateMqttClient();
        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
        // Calling _Dispose_ or use of a _using_ statement will close the transport connection
        // without sending a DISCONNECT packet to the server.
        mqttClient.Dispose();
    }
    public static async Task Inspect_Certificate_Validation_Errors()
    {
        /*
         * This sample prints the certificate information while connection. This data can be used to decide whether a connection is secure or not
         * including the reason for that status.
         */
        var mqttFactory = new MqttClientFactory();
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("mqtt.fluux.io", 8883)
                .WithTlsOptions(
                    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;
                            });
                    })
                .Build();
            // In MQTTv5 the response contains much more information.
            using (var timeout = new CancellationTokenSource(5000))
            {
                await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
            }
        }
    }
    public static async Task Ping_Server()
    {
        /*
         * This sample sends a PINGREQ packet to the server and waits for a reply.
         *
         * This is only supported in MQTTv5.0.0+.
         */
        var mqttFactory = new MqttClientFactory();
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
            // This will throw an exception if the server does not reply.
            await mqttClient.PingAsync(CancellationToken.None);
            Console.WriteLine("The MQTT server replied to the ping request.");
        }
    }
    public static async Task Reconnect_Using_Event()
    {
        /*
         * This sample shows how to reconnect when the connection was dropped.
         * This approach uses one of the events from the client.
         * This approach has a risk of dead locks! Consider using the timer approach (see sample).
         */
        var mqttFactory = new MqttClientFactory();
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
            mqttClient.DisconnectedAsync += async e =>
            {
                if (e.ClientWasConnected)
                {
                    // Use the current options as the new options.
                    await mqttClient.ConnectAsync(mqttClient.Options);
                }
            };
            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
        }
    }
    public static void Reconnect_Using_Timer()
    {
        /*
         * This sample shows how to reconnect when the connection was dropped.
         * This approach uses a custom Task/Thread which will monitor the connection status.
         * This is the recommended way but requires more custom code!
         */
        var mqttFactory = new MqttClientFactory();
        using (var mqttClient = mqttFactory.CreateMqttClient())
        {
            var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
            _ = Task.Run(
                async () =>
                {
                    // User proper cancellation and no while(true).
                    while (true)
                    {
                        try
                        {
                            // This code will also do the very first connect! So no call to _ConnectAsync_ is required in the first place.
                            if (!await mqttClient.TryPingAsync())
                            {
                                await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
                                // Subscribe to topics when session is clean etc.
                                Console.WriteLine("The MQTT client is connected.");
                            }
                        }
                        catch
                        {
                            // Handle the exception properly (logging etc.).
                        }
                        finally
                        {
                            // Check the connection state every 5 seconds and perform a reconnect if required.
                            await Task.Delay(TimeSpan.FromSeconds(5));
                        }
                    }
                });
            Console.WriteLine("Press <Enter> to exit");
            Console.ReadLine();
        }
    }
    public static async Task ConnectTls_WithCaFile()
    {
        var mqttFactory = new MqttClientFactory();
        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
@@ -460,4 +46,477 @@ m/XriWr/Cq4h/JfB7NTsezVslgkBaoU=
 -----END CERTIFICATE-----
 ";
    public static async Task Clean_Disconnect()
    {
        /*
         * This sample disconnects in a clean way. This will send a MQTT DISCONNECT packet
         * to the server and close the connection afterward.
         *
         * See sample _Connect_Client_ for more details.
         */
        var mqttFactory = new MqttClientFactory();
        using var mqttClient = mqttFactory.CreateMqttClient();
        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
        // This will send the DISCONNECT packet. Calling _Dispose_ without DisconnectAsync the
        // connection is closed in a "not clean" way. See MQTT specification for more details.
        await mqttClient.DisconnectAsync(new MqttClientDisconnectOptionsBuilder().WithReason(MqttClientDisconnectOptionsReason.NormalDisconnection).Build());
    }
    public static async Task Connect()
    {
        /*
         * This sample creates a simple MQTT client and connects to a public broker.
         *
         * Always dispose the client when it is no longer used.
         * The default version of MQTT is 3.1.1.
         */
        var mqttFactory = new MqttClientFactory();
        using var mqttClient = mqttFactory.CreateMqttClient();
        // Use builder classes where possible in this project.
        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
        // This will throw an exception if the server is not available.
        // The result from this message returns additional data which was sent
        // from the server. Please refer to the MQTT protocol specification for details.
        var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
        Console.WriteLine("The MQTT client is connected.");
        response.DumpToConsole();
        // Send a clean disconnect to the server by calling _DisconnectAsync_. Without this the TCP connection
        // gets dropped and the server will handle this as a non clean disconnect (see MQTT spec for details).
        var mqttClientDisconnectOptions = mqttFactory.CreateClientDisconnectOptionsBuilder().Build();
        await mqttClient.DisconnectAsync(mqttClientDisconnectOptions, CancellationToken.None);
    }
    public static async Task Connect_Using_Enhanced_Authentication()
    {
        /*
         * This sample uses enhanced authentication (Kerberos) when creating the connection.
         */
        /*
         * Server part...
         */
        var mqttServerFactory = new MqttServerFactory();
        var serverOptions = mqttServerFactory.CreateServerOptionsBuilder().WithDefaultEndpoint().Build();
        var server = mqttServerFactory.CreateMqttServer(serverOptions);
        server.ValidatingConnectionAsync += async args =>
        {
            if (args.AuthenticationMethod == "GS2-KRB5")
            {
                var result = await args.ExchangeEnhancedAuthenticationAsync(new ExchangeEnhancedAuthenticationOptions(), args.CancellationToken);
                Console.WriteLine($"Received AUTH data from client: {Encoding.UTF8.GetString(result.AuthenticationData)}");
                var authOptions = mqttServerFactory.CreateExchangeExtendedAuthenticationOptionsBuilder().WithAuthenticationData("reply context token").Build();
                result = await args.ExchangeEnhancedAuthenticationAsync(authOptions, args.CancellationToken);
                Console.WriteLine($"Received AUTH data from client: {Encoding.UTF8.GetString(result.AuthenticationData)}");
                args.ResponseAuthenticationData = "outcome of authentication"u8.ToArray();
                // Authentication DONE!
                args.ReasonCode = MqttConnectReasonCode.Success; // Also the default!
            }
            else
            {
                args.ReasonCode = MqttConnectReasonCode.BadAuthenticationMethod;
            }
        };
        await server.StartAsync();
        /*
         * Client part...
         */
        var mqttClientFactory = new MqttClientFactory();
        // Use Kerberos sample from the MQTT RFC.
        var kerberosAuthenticationHandler = new SampleClientKerberosAuthenticationHandler();
        var clientOptions = mqttClientFactory.CreateClientOptionsBuilder()
            .WithTcpServer("localhost")
            .WithProtocolVersion(MqttProtocolVersion.V500)
            .WithEnhancedAuthenticationHandler(kerberosAuthenticationHandler)
            .WithEnhancedAuthentication("GS2-KRB5")
            .Build();
        var client = mqttClientFactory.CreateMqttClient();
        var result = await client.ConnectAsync(clientOptions);
        Console.WriteLine($"Client connect result: {result.ResultCode}");
    }
    public static async Task Connect_Using_MQTTv5()
    {
        /*
         * This sample creates a simple MQTT client and connects to a public broker using MQTTv5.
         *
         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
         */
        var mqttFactory = new MqttClientFactory();
        using var mqttClient = mqttFactory.CreateMqttClient();
        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").WithProtocolVersion(MqttProtocolVersion.V500).Build();
        // In MQTTv5 the response contains much more information.
        var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
        Console.WriteLine("The MQTT client is connected.");
        response.DumpToConsole();
    }
    public static async Task Connect_Using_TLS_1_2()
    {
        /*
         * This sample creates a simple MQTT client and connects to a public broker using TLS 1.2 encryption.
         *
         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
         */
        var mqttFactory = new MqttClientFactory();
        using var mqttClient = mqttFactory.CreateMqttClient();
        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("mqtt.fluux.io")
            .WithTlsOptions(
                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);
                    // The default value is determined by the OS. Set manually to force version.
                    o.WithSslProtocols(SslProtocols.Tls12);
                })
            .Build();
        using var timeout = new CancellationTokenSource(5000);
        await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
        Console.WriteLine("The MQTT client is connected.");
    }
    public static async Task Connect_Using_TLS_Encryption()
    {
        /*
         * This sample creates a simple MQTT client and connects to a public broker with enabled TLS encryption.
         *
         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
         */
        var mqttFactory = new MqttClientFactory();
        using var mqttClient = mqttFactory.CreateMqttClient();
        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("test.mosquitto.org", 8883)
            .WithTlsOptions(
                o => o.WithCertificateValidationHandler(
                    // The used public broker sometimes has invalid certificates. This sample accepts all
                    // certificates. This should not be used in live environments.
                    _ => true))
            .Build();
        // In MQTTv5 the response contains much more information.
        using var timeout = new CancellationTokenSource(5000);
        var response = await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
        Console.WriteLine("The MQTT client is connected.");
        response.DumpToConsole();
    }
    public static async Task Connect_Using_TLS_With_CA_File()
    {
        var mqttFactory = new MqttClientFactory();
        var 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);
    }
    public static async Task Connect_Using_WebSockets()
    {
        /*
         * This sample creates a simple MQTT client and connects to a public broker using a WebSocket connection.
         *
         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
         */
        var mqttFactory = new MqttClientFactory();
        using var mqttClient = mqttFactory.CreateMqttClient();
        var mqttClientOptions = new MqttClientOptionsBuilder().WithWebSocketServer(o => o.WithUri("broker.hivemq.com:8000/mqtt")).Build();
        var response = await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
        Console.WriteLine("The MQTT client is connected.");
        response.DumpToConsole();
    }
    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 MqttClientFactory();
        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()
    {
        /*
         * This sample disconnects from the server with sending a DISCONNECT packet.
         * This way of disconnecting is treated as a clean disconnect which will not
         * trigger sending the last will etc.
         */
        var mqttFactory = new MqttClientFactory();
        using var mqttClient = mqttFactory.CreateMqttClient();
        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
        // Calling _DisconnectAsync_ will send a DISCONNECT packet before closing the connection.
        // Using a reason code requires MQTT version 5.0.0!
        await mqttClient.DisconnectAsync(MqttClientDisconnectOptionsReason.ImplementationSpecificError);
    }
    public static async Task Disconnect_Non_Clean()
    {
        /*
         * This sample disconnects from the server without sending a DISCONNECT packet.
         * This way of disconnecting is treated as a non-clean disconnect which will
         * trigger sending the last will etc.
         */
        var mqttFactory = new MqttClientFactory();
        var mqttClient = mqttFactory.CreateMqttClient();
        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
        // Calling _Dispose_ or use of a _using_ statement will close the transport connection
        // without sending a DISCONNECT packet to the server.
        mqttClient.Dispose();
    }
    public static async Task Inspect_Certificate_Validation_Errors()
    {
        /*
         * This sample prints the certificate information while connection. This data can be used to decide whether a connection is secure or not
         * including the reason for that status.
         */
        var mqttFactory = new MqttClientFactory();
        using var mqttClient = mqttFactory.CreateMqttClient();
        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("mqtt.fluux.io", 8883)
            .WithTlsOptions(
                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;
                        });
                })
            .Build();
        // In MQTTv5 the response contains much more information.
        using var timeout = new CancellationTokenSource(5000);
        await mqttClient.ConnectAsync(mqttClientOptions, timeout.Token);
    }
    public static async Task Ping_Server()
    {
        /*
         * This sample sends a PINGREQ packet to the server and waits for a reply.
         *
         * This is only supported in MQTTv5.0.0+.
         */
        var mqttFactory = new MqttClientFactory();
        using var mqttClient = mqttFactory.CreateMqttClient();
        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
        // This will throw an exception if the server does not reply.
        await mqttClient.PingAsync(CancellationToken.None);
        Console.WriteLine("The MQTT server replied to the ping request.");
    }
    public static async Task Reconnect_Using_Event()
    {
        /*
         * This sample shows how to reconnect when the connection was dropped.
         * This approach uses one of the events from the client.
         * This approach has a risk of deadlocks! Consider using the timer approach (see sample).
         */
        var mqttFactory = new MqttClientFactory();
        using var mqttClient = mqttFactory.CreateMqttClient();
        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
        mqttClient.DisconnectedAsync += async e =>
        {
            if (e.ClientWasConnected)
            {
                // Use the current options as the new options.
                await mqttClient.ConnectAsync(mqttClient.Options);
            }
        };
        await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
    }
    public static void Reconnect_Using_Timer()
    {
        /*
         * This sample shows how to reconnect when the connection was dropped.
         * This approach uses a custom Task/Thread which will monitor the connection status.
         * This is the recommended way but requires more custom code!
         */
        var mqttFactory = new MqttClientFactory();
        using var mqttClient = mqttFactory.CreateMqttClient();
        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("broker.hivemq.com").Build();
        _ = Task.Run(
            async () =>
            {
                // User proper cancellation and no while(true).
                while (true)
                {
                    try
                    {
                        // This code will also do the very first connect! So no call to _ConnectAsync_ is required in the first place.
                        if (!await mqttClient.TryPingAsync())
                        {
                            await mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
                            // Subscribe to topics when session is clean etc.
                            Console.WriteLine("The MQTT client is connected.");
                        }
                    }
                    catch
                    {
                        // Handle the exception properly (logging etc.).
                    }
                    finally
                    {
                        // Check the connection state every 5 seconds and perform a reconnect if required.
                        await Task.Delay(TimeSpan.FromSeconds(5));
                    }
                }
            });
        Console.WriteLine("Press <Enter> to exit");
        Console.ReadLine();
    }
    public static async Task Timeout()
    {
        /*
         * This sample creates a simple MQTT client and connects to an invalid broker using a timeout.
         *
         * This is a modified version of the sample _Connect_Client_! See other sample for more details.
         */
        var mqttFactory = new MqttClientFactory();
        using var mqttClient = mqttFactory.CreateMqttClient();
        var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1").Build();
        try
        {
            using var timeoutToken = new CancellationTokenSource(TimeSpan.FromSeconds(1));
            await mqttClient.ConnectAsync(mqttClientOptions, timeoutToken.Token);
        }
        catch (OperationCanceledException)
        {
            Console.WriteLine("Timeout while connecting.");
        }
    }
    class SampleClientKerberosAuthenticationHandler : IMqttEnhancedAuthenticationHandler
    {
        public async Task HandleEnhancedAuthenticationAsync(MqttEnhancedAuthenticationEventArgs eventArgs)
        {
            if (eventArgs.AuthenticationMethod != "GS2-KRB5")
            {
                throw new InvalidOperationException("Wrong authentication method");
            }
            var sendOptions = new SendMqttEnhancedAuthenticationDataOptions
            {
                Data = "initial context token"u8.ToArray()
            };
            await eventArgs.SendAsync(sendOptions);
            var response = await eventArgs.ReceiveAsync(CancellationToken.None);
            Console.WriteLine($"Received AUTH data from server: {Encoding.UTF8.GetString(response.AuthenticationData)}");
            // No further data is required, but we have to fulfil the exchange.
            sendOptions = new SendMqttEnhancedAuthenticationDataOptions
            {
                Data = []
            };
            await eventArgs.SendAsync(sendOptions, CancellationToken.None);
        }
    }
 }
@@ -102,10 +102,7 @@ public static class Server_Retained_Messages_Samples
        public static MqttRetainedMessageModel Create(MqttApplicationMessage message)
        {
-            if (message == null)
+            ArgumentNullException.ThrowIfNull(message);
            {
                throw new ArgumentNullException(nameof(message));
            }
            return new MqttRetainedMessageModel
            {
@@ -12,10 +12,7 @@ namespace MQTTnet.AspNetCore
    {
        public static void MapMqtt(this IEndpointRouteBuilder endpoints, string pattern)
        {
-            if (endpoints == null)
+            ArgumentNullException.ThrowIfNull(endpoints);
            {
                throw new ArgumentNullException(nameof(endpoints));
            }
            endpoints.MapConnectionHandler<MqttConnectionHandler>(pattern, options =>
            {
@@ -61,21 +61,21 @@ public sealed class MqttConnectionContext : IMqttChannelAdapter
        }
    }
-    public string Endpoint
+    public EndPoint RemoteEndPoint
    {
        get
        {
            // mqtt over tcp
            if (_connection.RemoteEndPoint != null)
            {
-                return _connection.RemoteEndPoint.ToString();
+                return _connection.RemoteEndPoint;
            }
            // mqtt over websocket
            var httpFeature = _connection.Features.Get<IHttpConnectionFeature>();
            if (httpFeature?.RemoteIpAddress != null)
            {
-                return new IPEndPoint(httpFeature.RemoteIpAddress, httpFeature.RemotePort).ToString();
+                return new IPEndPoint(httpFeature.RemoteIpAddress, httpFeature.RemotePort);
            }
            return null;
@@ -13,10 +13,7 @@ public static class MqttSubProtocolSelector
 {
    public static string SelectSubProtocol(HttpRequest request)
    {
-        if (request == null)
+        ArgumentNullException.ThrowIfNull(request);
        {
            throw new ArgumentNullException(nameof(request));
        }
        string subProtocol = null;
        if (request.Headers.TryGetValue("Sec-WebSocket-Protocol", out var requestedSubProtocolValues))
@@ -29,10 +26,7 @@ public static class MqttSubProtocolSelector
    public static string SelectSubProtocol(IList<string> requestedSubProtocolValues)
    {
-        if (requestedSubProtocolValues == null)
+        ArgumentNullException.ThrowIfNull(requestedSubProtocolValues);
        {
            throw new ArgumentNullException(nameof(requestedSubProtocolValues));
        }
        // Order the protocols to also match "mqtt", "mqttv-3.1", "mqttv-3.11" etc.
        return requestedSubProtocolValues.OrderByDescending(p => p.Length).FirstOrDefault(p => p.ToLower().StartsWith("mqtt"));
@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 using System;
 using System.Net;
 using System.Net.WebSockets;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
@@ -26,12 +27,10 @@ public sealed class MqttWebSocketServerAdapter : IMqttServerAdapter
    public async Task RunWebSocketConnectionAsync(WebSocket webSocket, HttpContext httpContext)
    {
-        if (webSocket == null)
+        ArgumentNullException.ThrowIfNull(webSocket);
        {
            throw new ArgumentNullException(nameof(webSocket));
        }
-        var endpoint = $"{httpContext.Connection.RemoteIpAddress}:{httpContext.Connection.RemotePort}";
+        var remoteAddress = httpContext.Connection.RemoteIpAddress;
        var remoteEndPoint = remoteAddress == null ? null : new IPEndPoint(remoteAddress, httpContext.Connection.RemotePort);
        var clientCertificate = await httpContext.Connection.GetClientCertificateAsync().ConfigureAwait(false);
        try
@@ -42,7 +41,7 @@ public sealed class MqttWebSocketServerAdapter : IMqttServerAdapter
            if (clientHandler != null)
            {
                var formatter = new MqttPacketFormatterAdapter(new MqttBufferWriter(4096, 65535));
-                var channel = new MqttWebSocketChannel(webSocket, endpoint, isSecureConnection, clientCertificate);
+                var channel = new MqttWebSocketChannel(webSocket, remoteEndPoint, isSecureConnection, clientCertificate);
                using (var channelAdapter = new MqttChannelAdapter(channel, formatter, _logger))
                {
@@ -22,10 +22,7 @@ public static class ReaderExtensions
        out SequencePosition observed,
        out int bytesRead)
    {
-        if (formatter == null)
+        ArgumentNullException.ThrowIfNull(formatter);
        {
            throw new ArgumentNullException(nameof(formatter));
        }
        packet = null;
        consumed = input.Start;
@@ -16,15 +16,8 @@ public static class ServiceCollectionExtensions
 {
    public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, MqttServerOptions options)
    {
-        if (services == null)
+        ArgumentNullException.ThrowIfNull(services);
-        {
+        ArgumentNullException.ThrowIfNull(options);
            throw new ArgumentNullException(nameof(services));
        }
        if (options == null)
        {
            throw new ArgumentNullException(nameof(options));
        }
        services.AddSingleton(options);
        services.AddHostedMqttServer();
@@ -34,10 +27,7 @@ public static class ServiceCollectionExtensions
    public static IServiceCollection AddHostedMqttServer(this IServiceCollection services, Action<MqttServerOptionsBuilder> configure)
    {
-        if (services == null)
+        ArgumentNullException.ThrowIfNull(services);
        {
            throw new ArgumentNullException(nameof(services));
        }
        var serverOptionsBuilder = new MqttServerOptionsBuilder();
@@ -61,10 +51,7 @@ public static class ServiceCollectionExtensions
    public static IServiceCollection AddHostedMqttServerWithServices(this IServiceCollection services, Action<AspNetMqttServerOptionsBuilder> configure)
    {
-        if (services == null)
+        ArgumentNullException.ThrowIfNull(services);
        {
            throw new ArgumentNullException(nameof(services));
        }
        services.AddSingleton(
            s =>
@@ -89,20 +76,14 @@ public static class ServiceCollectionExtensions
    public static void AddMqttLogger(this IServiceCollection services, IMqttNetLogger logger)
    {
-        if (services == null)
+        ArgumentNullException.ThrowIfNull(services);
        {
            throw new ArgumentNullException(nameof(services));
        }
        services.AddSingleton(logger);
    }
    public static IServiceCollection AddMqttServer(this IServiceCollection serviceCollection, Action<MqttServerOptionsBuilder> configure = null)
    {
-        if (serviceCollection is null)
+        ArgumentNullException.ThrowIfNull(serviceCollection);
        {
            throw new ArgumentNullException(nameof(serviceCollection));
        }
        serviceCollection.AddMqttConnectionHandler();
        serviceCollection.AddHostedMqttServer(configure);
@@ -18,7 +18,7 @@
    </PropertyGroup>
    <ItemGroup>
-        <PackageReference Include="BenchmarkDotNet" Version="0.13.12"/>
+        <PackageReference Include="BenchmarkDotNet" Version="0.14.0" />
    </ItemGroup>
    <ItemGroup>
@@ -145,7 +145,7 @@ namespace MQTTnet.Benchmarks
                out SequencePosition observed,
                out int bytesRead)
            {
-                if (formatter == null) throw new ArgumentNullException(nameof(formatter));
+                ArgumentNullException.ThrowIfNull(formatter);
                packet = null;
                consumed = input.Start;
@@ -15,6 +15,7 @@ using MQTTnet.Formatter.V3;
 using BenchmarkDotNet.Jobs;
 using MQTTnet.Diagnostics.Logger;
 using System.Buffers;
 using System.Net;
 namespace MQTTnet.Benchmarks
 {
@@ -76,7 +77,7 @@ namespace MQTTnet.Benchmarks
                _position = _buffer.Offset;
            }
-            public string Endpoint { get; } = string.Empty;
+            public EndPoint RemoteEndPoint { get; set; }
            public bool IsSecureConnection { get; } = false;
@@ -73,15 +73,8 @@ namespace MQTTnet.Benchmarks
        static bool LegacyMethodByStringSplit(string topic, string filter)
        {
-            if (topic == null)
+            ArgumentNullException.ThrowIfNull(topic);
-            {
+            ArgumentNullException.ThrowIfNull(filter);
                throw new ArgumentNullException(nameof(topic));
            }
            if (filter == null)
            {
                throw new ArgumentNullException(nameof(filter));
            }
            if (string.Equals(topic, filter, StringComparison.Ordinal))
            {
@@ -10,10 +10,7 @@ namespace MQTTnet.Extensions.Rpc
    {
        public MqttRpcTopicPair CreateRpcTopics(TopicGenerationContext context)
        {
-            if (context == null)
+            ArgumentNullException.ThrowIfNull(context);
            {
                throw new ArgumentNullException(nameof(context));
            }
            if (context.MethodName.Contains("/") || context.MethodName.Contains("+") || context.MethodName.Contains("#"))
            {
@@ -20,15 +20,8 @@ namespace MQTTnet.Extensions.Rpc
        public static IMqttRpcClient CreateMqttRpcClient(this MqttClientFactory _, IMqttClient mqttClient, MqttRpcClientOptions rpcClientOptions)
        {
-            if (mqttClient == null)
+            ArgumentNullException.ThrowIfNull(mqttClient);
-            {
+            ArgumentNullException.ThrowIfNull(rpcClientOptions);
                throw new ArgumentNullException(nameof(mqttClient));
            }
            if (rpcClientOptions == null)
            {
                throw new ArgumentNullException(nameof(rpcClientOptions));
            }
            return new MqttRpcClient(mqttClient, rpcClientOptions);
        }
@@ -65,10 +65,7 @@ namespace MQTTnet.Extensions.Rpc
        public async Task<byte[]> ExecuteAsync(string methodName, byte[] payload, MqttQualityOfServiceLevel qualityOfServiceLevel, IDictionary<string, object> parameters = null, CancellationToken cancellationToken = default)
        {
-            if (methodName == null)
+            ArgumentNullException.ThrowIfNull(methodName);
            {
                throw new ArgumentNullException(nameof(methodName));
            }
            var context = new TopicGenerationContext(_mqttClient, _options, methodName, parameters, qualityOfServiceLevel);
            var topicNames = _options.TopicGenerationStrategy.CreateRpcTopics(context);
@@ -41,10 +41,7 @@ public sealed class MqttTopicTemplate : IEquatable<MqttTopicTemplate>
    /// </exception>
    public MqttTopicTemplate(string topicTemplate)
    {
-        if (topicTemplate == null)
+        ArgumentNullException.ThrowIfNull(topicTemplate);
        {
            throw new ArgumentNullException(nameof(topicTemplate));
        }
        MqttTopicValidator.ThrowIfInvalidSubscribe(topicTemplate);
@@ -0,0 +1,16 @@
 // 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.Packets;
 namespace MQTTnet.Server.EnhancedAuthentication;
 public sealed class ExchangeEnhancedAuthenticationOptions
 {
    public byte[] AuthenticationData { get; set; }
    public string ReasonString { get; set; }
    public List<MqttUserProperty> UserProperties { get; set; }
 }
@@ -0,0 +1,70 @@
 // 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.Text;
 using MQTTnet.Packets;
 namespace MQTTnet.Server.EnhancedAuthentication;
 public sealed class ExchangeEnhancedAuthenticationOptionsFactory
 {
    readonly ExchangeEnhancedAuthenticationOptions _options = new();
    public ExchangeEnhancedAuthenticationOptions Build()
    {
        return _options;
    }
    public ExchangeEnhancedAuthenticationOptionsFactory WithAuthenticationData(byte[] authenticationData)
    {
        _options.AuthenticationData = authenticationData;
        return this;
    }
    public ExchangeEnhancedAuthenticationOptionsFactory WithAuthenticationData(string authenticationData)
    {
        if (authenticationData == null)
        {
            _options.AuthenticationData = null;
        }
        else
        {
            _options.AuthenticationData = Encoding.UTF8.GetBytes(authenticationData);
        }
        return this;
    }
    public ExchangeEnhancedAuthenticationOptionsFactory WithReasonString(string reasonString)
    {
        _options.ReasonString = reasonString;
        return this;
    }
    public ExchangeEnhancedAuthenticationOptionsFactory WithUserProperties(List<MqttUserProperty> userProperties)
    {
        _options.UserProperties = userProperties;
        return this;
    }
    public ExchangeEnhancedAuthenticationOptionsFactory WithUserProperty(string name, string value)
    {
        if (name == null)
        {
            throw new ArgumentNullException(nameof(name));
        }
        if (_options.UserProperties == null)
        {
            _options.UserProperties = new List<MqttUserProperty>();
        }
        _options.UserProperties.Add(new MqttUserProperty(name, value));
        return this;
    }
 }
@@ -0,0 +1,12 @@
 using MQTTnet.Packets;
 namespace MQTTnet.Server.EnhancedAuthentication;
 public sealed class ExchangeEnhancedAuthenticationResult
 {
    public string ReasonString { get; set; }
    public List<MqttUserProperty> UserProperties { get; set; }
    public byte[] AuthenticationData { get; set; }
 }
@@ -0,0 +1,34 @@
 using MQTTnet.Packets;
 namespace MQTTnet.Server.EnhancedAuthentication;
 public static class ExchangeEnhancedAuthenticationResultFactory
 {
    public static ExchangeEnhancedAuthenticationResult Create(MqttAuthPacket authPacket)
    {
        ArgumentNullException.ThrowIfNull(authPacket);
        return new ExchangeEnhancedAuthenticationResult
        {
            AuthenticationData = authPacket.AuthenticationData,
            ReasonString = authPacket.ReasonString,
            UserProperties = authPacket.UserProperties
        };
    }
    public static ExchangeEnhancedAuthenticationResult Create(MqttDisconnectPacket disconnectPacket)
    {
        ArgumentNullException.ThrowIfNull(disconnectPacket);
        return new ExchangeEnhancedAuthenticationResult
        {
            AuthenticationData = null,
            ReasonString = disconnectPacket.ReasonString,
            UserProperties = disconnectPacket.UserProperties
            // SessionExpiryInterval makes no sense because the connection is not yet made!
            // ServerReferences makes no sense when the client initiated a DISCONNECT!
        };
    }
 }
@@ -10,9 +10,10 @@ namespace MQTTnet.Server
 {
    public sealed class ClientAcknowledgedPublishPacketEventArgs : EventArgs
    {
-        public ClientAcknowledgedPublishPacketEventArgs(string clientId, IDictionary sessionItems, MqttPublishPacket publishPacket, MqttPacketWithIdentifier acknowledgePacket)
+        public ClientAcknowledgedPublishPacketEventArgs(string clientId, string userName, IDictionary sessionItems, MqttPublishPacket publishPacket, MqttPacketWithIdentifier acknowledgePacket)
        {
            ClientId = clientId ?? throw new ArgumentNullException(nameof(clientId));
            UserName = userName;
            SessionItems = sessionItems ?? throw new ArgumentNullException(nameof(sessionItems));
            PublishPacket = publishPacket ?? throw new ArgumentNullException(nameof(publishPacket));
            AcknowledgePacket = acknowledgePacket ?? throw new ArgumentNullException(nameof(acknowledgePacket));
@@ -28,6 +29,11 @@ namespace MQTTnet.Server
        /// </summary>
        public string ClientId { get; }
        /// <summary>
        /// Gets the user name of the client.
        /// </summary>
        public string UserName { get; }
        /// <summary>
        ///     Gets whether the PUBLISH packet is fully acknowledged. This is the case for PUBACK (QoS 1) and PUBCOMP (QoS 2.
        /// </summary>
@@ -5,6 +5,8 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Net;
 using System.Text;
 using MQTTnet.Formatter;
 using MQTTnet.Packets;
@@ -14,11 +16,11 @@ namespace MQTTnet.Server
    {
        readonly MqttConnectPacket _connectPacket;
-        public ClientConnectedEventArgs(MqttConnectPacket connectPacket, MqttProtocolVersion protocolVersion, string endpoint, IDictionary sessionItems)
+        public ClientConnectedEventArgs(MqttConnectPacket connectPacket, MqttProtocolVersion protocolVersion, EndPoint remoteEndPoint, IDictionary sessionItems)
        {
            _connectPacket = connectPacket ?? throw new ArgumentNullException(nameof(connectPacket));
            ProtocolVersion = protocolVersion;
-            Endpoint = endpoint;
+            RemoteEndPoint = remoteEndPoint;
            SessionItems = sessionItems ?? throw new ArgumentNullException(nameof(sessionItems));
        }
@@ -35,7 +37,10 @@ namespace MQTTnet.Server
        /// <summary>
        ///     Gets the endpoint of the connected client.
        /// </summary>
-        public string Endpoint { get; }
+        public EndPoint RemoteEndPoint { get; }
        [Obsolete("Use RemoteEndPoint instead.")]
        public string Endpoint => RemoteEndPoint?.ToString();
        /// <summary>
        ///     Gets the protocol version which is used by the connected client.
@@ -52,6 +57,11 @@ namespace MQTTnet.Server
        /// </summary>
        public string UserName => _connectPacket.Username;
        /// <summary>
        ///     Gets the password of the connected client.
        /// </summary>
        public string Password => Encoding.UTF8.GetString(_connectPacket.Password.AsSpan());
        /// <summary>
        ///     Gets the user properties sent by the client.
        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
@@ -5,6 +5,8 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Net;
 using System.Text;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
@@ -12,20 +14,21 @@ namespace MQTTnet.Server
 {
    public sealed class ClientDisconnectedEventArgs : EventArgs
    {
        readonly MqttConnectPacket _connectPacket;
        readonly MqttDisconnectPacket _disconnectPacket;
        public ClientDisconnectedEventArgs(
-            string clientId,
+            MqttConnectPacket connectPacket,
            MqttDisconnectPacket disconnectPacket,
            MqttClientDisconnectType disconnectType,
-            string endpoint,
+            EndPoint remoteEndPoint,
            IDictionary sessionItems)
        {
            ClientId = clientId ?? throw new ArgumentNullException(nameof(clientId));
            DisconnectType = disconnectType;
-            Endpoint = endpoint;
+            RemoteEndPoint = remoteEndPoint;
            SessionItems = sessionItems ?? throw new ArgumentNullException(nameof(sessionItems));
            _connectPacket = connectPacket;
            // The DISCONNECT packet can be null in case of a non clean disconnect or session takeover.
            _disconnectPacket = disconnectPacket;
        }
@@ -34,11 +37,24 @@ namespace MQTTnet.Server
        ///     Gets the client identifier.
        ///     Hint: This identifier needs to be unique over all used clients / devices on the broker to avoid connection issues.
        /// </summary>
-        public string ClientId { get; }
+        public string ClientId => _connectPacket.ClientId;
        /// <summary>
        ///     Gets the user name of the client.
        /// </summary>
        public string UserName => _connectPacket.Username;
        /// <summary>
        ///     Gets the password of the client.
        /// </summary>
        public string Password => Encoding.UTF8.GetString(_connectPacket.Password.AsSpan());
        public MqttClientDisconnectType DisconnectType { get; }
-        public string Endpoint { get; }
+        public EndPoint RemoteEndPoint { get; }
        [Obsolete("Use RemoteEndPoint instead.")]
        public string Endpoint => RemoteEndPoint?.ToString();
        /// <summary>
        ///     Gets the reason code sent by the client.
@@ -10,9 +10,10 @@ namespace MQTTnet.Server
 {
    public sealed class ClientSubscribedTopicEventArgs : EventArgs
    {
-        public ClientSubscribedTopicEventArgs(string clientId, MqttTopicFilter topicFilter, IDictionary sessionItems)
+        public ClientSubscribedTopicEventArgs(string clientId, string userName, MqttTopicFilter topicFilter, IDictionary sessionItems)
        {
            ClientId = clientId ?? throw new ArgumentNullException(nameof(clientId));
            UserName = userName;
            TopicFilter = topicFilter ?? throw new ArgumentNullException(nameof(topicFilter));
            SessionItems = sessionItems ?? throw new ArgumentNullException(nameof(sessionItems));
        }
@@ -23,6 +24,11 @@ namespace MQTTnet.Server
        /// </summary>
        public string ClientId { get; }
        /// <summary>
        /// Gets the user name of the client.
        /// </summary>
        public string UserName { get; }
        /// <summary>
        ///     Gets or sets a key/value collection that can be used to share data within the scope of this session.
        /// </summary>
@@ -9,9 +9,10 @@ namespace MQTTnet.Server
 {
    public sealed class ClientUnsubscribedTopicEventArgs : EventArgs
    {
-        public ClientUnsubscribedTopicEventArgs(string clientId, string topicFilter, IDictionary sessionItems)
+        public ClientUnsubscribedTopicEventArgs(string clientId, string userName, string topicFilter, IDictionary sessionItems)
        {
            ClientId = clientId ?? throw new ArgumentNullException(nameof(clientId));
            UserName = userName;
            TopicFilter = topicFilter ?? throw new ArgumentNullException(nameof(topicFilter));
            SessionItems = sessionItems ?? throw new ArgumentNullException(nameof(sessionItems));
        }
@@ -22,6 +23,11 @@ namespace MQTTnet.Server
        /// </summary>
        public string ClientId { get; }
        /// <summary>
        /// Gets the user name of the client.
        /// </summary>
        public string UserName { get; }
        /// <summary>
        ///     Gets or sets a key/value collection that can be used to share data within the scope of this session.
        /// </summary>
@@ -4,6 +4,7 @@
 using System;
 using System.Collections;
 using System.Net;
 using System.Threading;
 using MQTTnet.Packets;
@@ -11,11 +12,12 @@ namespace MQTTnet.Server
 {
    public sealed class InterceptingPacketEventArgs : EventArgs
    {
-        public InterceptingPacketEventArgs(CancellationToken cancellationToken, string clientId, string endpoint, MqttPacket packet, IDictionary sessionItems)
+        public InterceptingPacketEventArgs(CancellationToken cancellationToken, string clientId, string userName, EndPoint remoteEndPoint, MqttPacket packet, IDictionary sessionItems)
        {
            CancellationToken = cancellationToken;
            ClientId = clientId ?? throw new ArgumentNullException(nameof(clientId));
-            Endpoint = endpoint;
+            UserName = userName;
            RemoteEndPoint = remoteEndPoint;
            Packet = packet ?? throw new ArgumentNullException(nameof(packet));
            SessionItems = sessionItems;
        }
@@ -31,10 +33,18 @@ namespace MQTTnet.Server
        /// </summary>
        public string ClientId { get; }
        /// <summary>
        /// Gets the user name of the client.
        /// </summary>
        public string UserName { get; }
        /// <summary>
        ///     Gets the endpoint of the sending or receiving client.
        /// </summary>
-        public string Endpoint { get; }
+        public EndPoint RemoteEndPoint { get; }
        [Obsolete("Use RemoteEndPoint instead.")]
        public string Endpoint => RemoteEndPoint?.ToString();
        /// <summary>
        ///     Gets or sets the MQTT packet which was received or will be sent.
@@ -10,11 +10,12 @@ namespace MQTTnet.Server
 {
    public sealed class InterceptingPublishEventArgs : EventArgs
    {
-        public InterceptingPublishEventArgs(MqttApplicationMessage applicationMessage, CancellationToken cancellationToken, string clientId, IDictionary sessionItems)
+        public InterceptingPublishEventArgs(MqttApplicationMessage applicationMessage, CancellationToken cancellationToken, string clientId, string userName, IDictionary sessionItems)
        {
            ApplicationMessage = applicationMessage ?? throw new ArgumentNullException(nameof(applicationMessage));
            CancellationToken = cancellationToken;
            ClientId = clientId ?? throw new ArgumentNullException(nameof(clientId));
            UserName = userName;
            SessionItems = sessionItems ?? throw new ArgumentNullException(nameof(sessionItems));
        }
@@ -31,6 +32,11 @@ namespace MQTTnet.Server
        /// </summary>
        public string ClientId { get; }
        /// <summary>
        /// Gets the user name of the client.
        /// </summary>
        public string UserName { get; }
        public bool CloseConnection { get; set; }
        /// <summary>
@@ -15,12 +15,14 @@ namespace MQTTnet.Server
        public InterceptingSubscriptionEventArgs(
            CancellationToken cancellationToken,
            string clientId,
            string userName,
            MqttSessionStatus session,
            MqttTopicFilter topicFilter,
            List<MqttUserProperty> userProperties)
        {
            CancellationToken = cancellationToken;
            ClientId = clientId;
            UserName = userName;
            Session = session;
            TopicFilter = topicFilter;
            UserProperties = userProperties;
@@ -37,6 +39,11 @@ namespace MQTTnet.Server
        /// </summary>
        public string ClientId { get; }
        /// <summary>
        /// Gets the user name of the client.
        /// </summary>
        public string UserName { get; }
        /// <summary>
        ///     Gets or sets whether the broker should close the client connection.
        /// </summary>
@@ -12,10 +12,11 @@ namespace MQTTnet.Server
 {
    public sealed class InterceptingUnsubscriptionEventArgs : EventArgs
    {
-        public InterceptingUnsubscriptionEventArgs(CancellationToken cancellationToken, string clientId, IDictionary sessionItems, string topic, List<MqttUserProperty> userProperties)
+        public InterceptingUnsubscriptionEventArgs(CancellationToken cancellationToken, string clientId, string userName, IDictionary sessionItems, string topic, List<MqttUserProperty> userProperties)
        {
            CancellationToken = cancellationToken;
            ClientId = clientId;
            UserName = userName;
            SessionItems = sessionItems;
            Topic = topic;
            UserProperties = userProperties;
@@ -32,6 +33,11 @@ namespace MQTTnet.Server
        /// </summary>
        public string ClientId { get; }
        /// <summary>
        /// Gets the user name of the client.
        /// </summary>
        public string UserName { get; } 
        /// <summary>
        ///     Gets or sets whether the broker should close the client connection.
        /// </summary>
@@ -9,9 +9,10 @@ namespace MQTTnet.Server
 {
    public sealed class SessionDeletedEventArgs : EventArgs
    {
-        public SessionDeletedEventArgs(string id, IDictionary sessionItems)
+        public SessionDeletedEventArgs(string id, string userName, IDictionary sessionItems)
        {
            Id = id ?? throw new ArgumentNullException(nameof(id));
            UserName = userName;
            SessionItems = sessionItems ?? throw new ArgumentNullException(nameof(sessionItems));
        }
@@ -20,6 +21,11 @@ namespace MQTTnet.Server
        /// </summary>
        public string Id { get; }
        /// <summary>
        /// Gets the user name of the session.
        /// </summary>
        public string UserName { get; }
        /// <summary>
        ///     Gets or sets a key/value collection that can be used to share data within the scope of this session.
        /// </summary>
@@ -2,189 +2,243 @@
 // 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;
-using System.Collections.Generic;
+using System.Net;
 using System.Security.Cryptography.X509Certificates;
 using System.Text;
 using MQTTnet.Adapter;
 using MQTTnet.Exceptions;
 using MQTTnet.Formatter;
 using MQTTnet.Internal;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
 using MQTTnet.Server.EnhancedAuthentication;
-namespace MQTTnet.Server
+namespace MQTTnet.Server;
 public sealed class ValidatingConnectionEventArgs : EventArgs
 {
-    public sealed class ValidatingConnectionEventArgs : EventArgs
+    readonly MqttConnectPacket _connectPacket;
    {
        readonly MqttConnectPacket _connectPacket;
-        public ValidatingConnectionEventArgs(MqttConnectPacket connectPacket, IMqttChannelAdapter clientAdapter, IDictionary sessionItems)
+    public ValidatingConnectionEventArgs(MqttConnectPacket connectPacket, IMqttChannelAdapter clientAdapter, IDictionary sessionItems, CancellationToken cancellationToken)
    {
        _connectPacket = connectPacket ?? throw new ArgumentNullException(nameof(connectPacket));
        ChannelAdapter = clientAdapter ?? throw new ArgumentNullException(nameof(clientAdapter));
        SessionItems = sessionItems ?? throw new ArgumentNullException(nameof(sessionItems));
        CancellationToken = cancellationToken;
    }
    /// <summary>
    ///     Gets or sets the assigned client identifier.
    ///     MQTTv5 only.
    /// </summary>
    public string AssignedClientIdentifier { get; set; }
    /// <summary>
    ///     Gets or sets the authentication data.
    ///     <remarks>MQTT 5.0.0+ feature.</remarks>
    /// </summary>
    public byte[] AuthenticationData => _connectPacket.AuthenticationData;
    /// <summary>
    ///     Gets or sets the authentication method.
    ///     <remarks>MQTT 5.0.0+ feature.</remarks>
    /// </summary>
    public string AuthenticationMethod => _connectPacket.AuthenticationMethod;
    public CancellationToken CancellationToken { get; }
    /// <summary>
    ///     Gets the channel adapter. This can be a _MqttConnectionContext_ (used in ASP.NET), a _MqttChannelAdapter_ (used for
    ///     TCP or WebSockets) or a custom implementation.
    /// </summary>
    public IMqttChannelAdapter ChannelAdapter { get; }
    /// <summary>
    ///     Gets or sets a value indicating whether clean sessions are used or not.
    ///     When a client connects to a broker it can connect using either a non persistent connection (clean session) or a
    ///     persistent connection.
    ///     With a non persistent connection the broker doesn't store any subscription information or undelivered messages for
    ///     the client.
    ///     This mode is ideal when the client only publishes messages.
    ///     It can also connect as a durable client using a persistent connection.
    ///     In this mode, the broker will store subscription information, and undelivered messages for the client.
    /// </summary>
    public bool? CleanSession => _connectPacket.CleanSession;
    public X509Certificate2 ClientCertificate => ChannelAdapter.ClientCertificate;
    /// <summary>
    ///     Gets the client identifier.
    ///     Hint: This identifier needs to be unique over all used clients / devices on the broker to avoid connection issues.
    /// </summary>
    public string ClientId => _connectPacket.ClientId;
    [Obsolete("Use RemoteEndPoint instead.")]
    public string Endpoint => RemoteEndPoint?.ToString();
    public bool IsSecureConnection => ChannelAdapter.IsSecureConnection;
    /// <summary>
    ///     Gets or sets the keep alive period.
    ///     The connection is normally left open by the client so that is can send and receive data at any time.
    ///     If no data flows over an open connection for a certain time period then the client will generate a PINGREQ and
    ///     expect to receive a PINGRESP from the broker.
    ///     This message exchange confirms that the connection is open and working.
    ///     This period is known as the keep alive period.
    /// </summary>
    public ushort? KeepAlivePeriod => _connectPacket.KeepAlivePeriod;
    /// <summary>
    ///     A value of 0 indicates that the value is not used.
    /// </summary>
    public uint MaximumPacketSize => _connectPacket.MaximumPacketSize;
    public string Password => Encoding.UTF8.GetString(RawPassword ?? EmptyBuffer.Array);
    public MqttProtocolVersion ProtocolVersion => ChannelAdapter.PacketFormatterAdapter.ProtocolVersion;
    public byte[] RawPassword => _connectPacket.Password;
    /// <summary>
    ///     Gets or sets the reason code. When a MQTTv3 client connects the enum value must be one which is
    ///     also supported in MQTTv3. Otherwise the connection attempt will fail because not all codes can be
    ///     converted properly.
    ///     <remarks>MQTT 5.0.0+ feature.</remarks>
    /// </summary>
    public MqttConnectReasonCode ReasonCode { get; set; } = MqttConnectReasonCode.Success;
    public string ReasonString { get; set; }
    /// <summary>
    ///     Gets or sets the receive maximum.
    ///     This gives the maximum length of the received messages.
    ///     A value of 0 indicates that the value is not used.
    /// </summary>
    public ushort ReceiveMaximum => _connectPacket.ReceiveMaximum;
    public EndPoint RemoteEndPoint => ChannelAdapter.RemoteEndPoint;
    /// <summary>
    ///     Gets the request problem information.
    ///     <remarks>MQTT 5.0.0+ feature.</remarks>
    /// </summary>
    public bool RequestProblemInformation => _connectPacket.RequestProblemInformation;
    /// <summary>
    ///     Gets the request response information.
    ///     <remarks>MQTT 5.0.0+ feature.</remarks>
    /// </summary>
    public bool RequestResponseInformation => _connectPacket.RequestResponseInformation;
    /// <summary>
    ///     Gets or sets the response authentication data.
    ///     <remarks>MQTT 5.0.0+ feature.</remarks>
    /// </summary>
    public byte[] ResponseAuthenticationData { get; set; }
    /// <summary>
    ///     Gets or sets the response user properties.
    ///     In MQTT 5, user properties are basic UTF-8 string key-value pairs that you can append to almost every type of MQTT
    ///     packet.
    ///     As long as you don’t exceed the maximum message size, you can use an unlimited number of user properties to add
    ///     metadata to MQTT messages and pass information between publisher, broker, and subscriber.
    ///     The feature is very similar to the HTTP header concept.
    ///     <remarks>MQTT 5.0.0+ feature.</remarks>
    /// </summary>
    public List<MqttUserProperty> ResponseUserProperties { get; set; }
    /// <summary>
    ///     Gets or sets the server reference. This can be used together with i.e. "Server Moved" to send
    ///     a different server address to the client.
    ///     <remarks>MQTT 5.0.0+ feature.</remarks>
    /// </summary>
    public string ServerReference { get; set; }
    /// <summary>
    ///     Gets the session expiry interval.
    ///     The time after a session expires when it's not actively used.
    ///     A value of 0 means no expiation.
    /// </summary>
    public uint SessionExpiryInterval => _connectPacket.SessionExpiryInterval;
    /// <summary>
    ///     Gets or sets a key/value collection that can be used to share data within the scope of this session.
    /// </summary>
    public IDictionary SessionItems { get; }
    /// <summary>
    ///     Gets or sets the topic alias maximum.
    ///     This gives the maximum length of the topic alias.
    ///     A value of 0 indicates that the value is not used.
    /// </summary>
    public ushort TopicAliasMaximum => _connectPacket.TopicAliasMaximum;
    public string UserName => _connectPacket.Username;
    /// <summary>
    ///     Gets or sets the user properties.
    ///     In MQTT 5, user properties are basic UTF-8 string key-value pairs that you can append to almost every type of MQTT
    ///     packet.
    ///     As long as you don’t exceed the maximum message size, you can use an unlimited number of user properties to add
    ///     metadata to MQTT messages and pass information between publisher, broker, and subscriber.
    ///     The feature is very similar to the HTTP header concept.
    ///     <remarks>MQTT 5.0.0+ feature.</remarks>
    /// </summary>
    public List<MqttUserProperty> UserProperties => _connectPacket.UserProperties;
    /// <summary>
    ///     Gets or sets the delay interval for the will message.
    ///     This is the time between the client disconnect and the time the will message will be sent.
    ///     A value of 0 indicates that the value is not used.
    /// </summary>
    public uint WillDelayInterval => _connectPacket.WillDelayInterval;
    public async Task<ExchangeEnhancedAuthenticationResult> ExchangeEnhancedAuthenticationAsync(
        ExchangeEnhancedAuthenticationOptions options,
        CancellationToken cancellationToken = default)
    {
        ArgumentNullException.ThrowIfNull(options);
        var requestAuthPacket = new MqttAuthPacket
        {
-            _connectPacket = connectPacket ?? throw new ArgumentNullException(nameof(connectPacket));
+            // From RFC: If the initial CONNECT packet included an Authentication Method property then all AUTH packets,
-            ChannelAdapter = clientAdapter ?? throw new ArgumentNullException(nameof(clientAdapter));
+            // and any successful CONNACK packet MUST include an Authentication Method Property with the same value as in the CONNECT packet [MQTT-4.12.0-5].
-            SessionItems = sessionItems ?? throw new ArgumentNullException(nameof(sessionItems));
+            AuthenticationMethod = AuthenticationMethod,
            // The reason code will stay at continue all the time when connecting. The server will respond with the
            // CONNACK packet when authentication is done!
            ReasonCode = MqttAuthenticateReasonCode.ContinueAuthentication,
            AuthenticationData = options.AuthenticationData,
            ReasonString = options.ReasonString,
            UserProperties = options.UserProperties
        };
        await ChannelAdapter.SendPacketAsync(requestAuthPacket, cancellationToken).ConfigureAwait(false);
        var responsePacket = await ChannelAdapter.ReceivePacketAsync(cancellationToken).ConfigureAwait(false);
        if (responsePacket == null)
        {
            throw new MqttCommunicationException("The client closed the connection.");
        }
-        /// <summary>
+        if (responsePacket is MqttAuthPacket responseAuthPacket)
-        ///     Gets or sets the assigned client identifier.
+        {
-        ///     MQTTv5 only.
+            if (!string.Equals(AuthenticationMethod, responseAuthPacket.AuthenticationMethod, StringComparison.Ordinal))
-        /// </summary>
+            {
-        public string AssignedClientIdentifier { get; set; }
+                throw new MqttProtocolViolationException("The authentication method cannot change while authenticating the client.");
            }
-        /// <summary>
+            return ExchangeEnhancedAuthenticationResultFactory.Create(responseAuthPacket);
-        ///     Gets or sets the authentication data.
+        }
        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
        /// </summary>
        public byte[] AuthenticationData => _connectPacket.AuthenticationData;
-        /// <summary>
+        if (responsePacket is MqttDisconnectPacket disconnectPacket)
-        ///     Gets or sets the authentication method.
+        {
-        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
+            return ExchangeEnhancedAuthenticationResultFactory.Create(disconnectPacket);
-        /// </summary>
+        }
        public string AuthenticationMethod => _connectPacket.AuthenticationMethod;
-        /// <summary>
+        throw new MqttProtocolViolationException("Received other packet than AUTH while authenticating.");
        ///     Gets the channel adapter. This can be a _MqttConnectionContext_ (used in ASP.NET), a _MqttChannelAdapter_ (used for
        ///     TCP or WebSockets) or a custom implementation.
        /// </summary>
        public IMqttChannelAdapter ChannelAdapter { get; }
        /// <summary>
        ///     Gets or sets a value indicating whether clean sessions are used or not.
        ///     When a client connects to a broker it can connect using either a non persistent connection (clean session) or a
        ///     persistent connection.
        ///     With a non persistent connection the broker doesn't store any subscription information or undelivered messages for
        ///     the client.
        ///     This mode is ideal when the client only publishes messages.
        ///     It can also connect as a durable client using a persistent connection.
        ///     In this mode, the broker will store subscription information, and undelivered messages for the client.
        /// </summary>
        public bool? CleanSession => _connectPacket.CleanSession;
        public X509Certificate2 ClientCertificate => ChannelAdapter.ClientCertificate;
        /// <summary>
        ///     Gets the client identifier.
        ///     Hint: This identifier needs to be unique over all used clients / devices on the broker to avoid connection issues.
        /// </summary>
        public string ClientId => _connectPacket.ClientId;
        public string Endpoint => ChannelAdapter.Endpoint;
        public bool IsSecureConnection => ChannelAdapter.IsSecureConnection;
        /// <summary>
        ///     Gets or sets the keep alive period.
        ///     The connection is normally left open by the client so that is can send and receive data at any time.
        ///     If no data flows over an open connection for a certain time period then the client will generate a PINGREQ and
        ///     expect to receive a PINGRESP from the broker.
        ///     This message exchange confirms that the connection is open and working.
        ///     This period is known as the keep alive period.
        /// </summary>
        public ushort? KeepAlivePeriod => _connectPacket.KeepAlivePeriod;
        /// <summary>
        ///     A value of 0 indicates that the value is not used.
        /// </summary>
        public uint MaximumPacketSize => _connectPacket.MaximumPacketSize;
        public string Password => Encoding.UTF8.GetString(RawPassword ?? EmptyBuffer.Array);
        public MqttProtocolVersion ProtocolVersion => ChannelAdapter.PacketFormatterAdapter.ProtocolVersion;
        public byte[] RawPassword => _connectPacket.Password;
        /// <summary>
        ///     Gets or sets the reason code. When a MQTTv3 client connects the enum value must be one which is
        ///     also supported in MQTTv3. Otherwise the connection attempt will fail because not all codes can be
        ///     converted properly.
        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
        /// </summary>
        public MqttConnectReasonCode ReasonCode { get; set; } = MqttConnectReasonCode.Success;
        public string ReasonString { get; set; }
        /// <summary>
        ///     Gets or sets the receive maximum.
        ///     This gives the maximum length of the receive messages.
        ///     A value of 0 indicates that the value is not used.
        /// </summary>
        public ushort ReceiveMaximum => _connectPacket.ReceiveMaximum;
        /// <summary>
        ///     Gets the request problem information.
        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
        /// </summary>
        public bool RequestProblemInformation => _connectPacket.RequestProblemInformation;
        /// <summary>
        ///     Gets the request response information.
        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
        /// </summary>
        public bool RequestResponseInformation => _connectPacket.RequestResponseInformation;
        /// <summary>
        ///     Gets or sets the response authentication data.
        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
        /// </summary>
        public byte[] ResponseAuthenticationData { get; set; }
        /// <summary>
        ///     Gets or sets the response user properties.
        ///     In MQTT 5, user properties are basic UTF-8 string key-value pairs that you can append to almost every type of MQTT
        ///     packet.
        ///     As long as you don’t exceed the maximum message size, you can use an unlimited number of user properties to add
        ///     metadata to MQTT messages and pass information between publisher, broker, and subscriber.
        ///     The feature is very similar to the HTTP header concept.
        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
        /// </summary>
        public List<MqttUserProperty> ResponseUserProperties { get; set; }
        /// <summary>
        ///     Gets or sets the server reference. This can be used together with i.e. "Server Moved" to send
        ///     a different server address to the client.
        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
        /// </summary>
        public string ServerReference { get; set; }
        /// <summary>
        ///     Gets the session expiry interval.
        ///     The time after a session expires when it's not actively used.
        ///     A value of 0 means no expiation.
        /// </summary>
        public uint SessionExpiryInterval => _connectPacket.SessionExpiryInterval;
        /// <summary>
        ///     Gets or sets a key/value collection that can be used to share data within the scope of this session.
        /// </summary>
        public IDictionary SessionItems { get; }
        /// <summary>
        ///     Gets or sets the topic alias maximum.
        ///     This gives the maximum length of the topic alias.
        ///     A value of 0 indicates that the value is not used.
        /// </summary>
        public ushort TopicAliasMaximum => _connectPacket.TopicAliasMaximum;
        public string UserName => _connectPacket.Username;
        /// <summary>
        ///     Gets or sets the user properties.
        ///     In MQTT 5, user properties are basic UTF-8 string key-value pairs that you can append to almost every type of MQTT
        ///     packet.
        ///     As long as you don’t exceed the maximum message size, you can use an unlimited number of user properties to add
        ///     metadata to MQTT messages and pass information between publisher, broker, and subscriber.
        ///     The feature is very similar to the HTTP header concept.
        ///     <remarks>MQTT 5.0.0+ feature.</remarks>
        /// </summary>
        public List<MqttUserProperty> UserProperties => _connectPacket.UserProperties;
        /// <summary>
        ///     Gets or sets the will delay interval.
        ///     This is the time between the client disconnect and the time the will message will be sent.
        ///     A value of 0 indicates that the value is not used.
        /// </summary>
        public uint WillDelayInterval => _connectPacket.WillDelayInterval;
    }
 }
@@ -23,4 +23,6 @@ public sealed class InjectedMqttApplicationMessage
    public IDictionary CustomSessionItems { get; set; }
    public string SenderClientId { get; set; } = string.Empty;
    public string SenderUserName { get; set; }
 }
@@ -167,11 +167,11 @@ namespace MQTTnet.Server.Internal.Adapter
        async Task TryHandleClientConnectionAsync(CrossPlatformSocket clientSocket)
        {
            Stream stream = null;
-            string remoteEndPoint = null;
+            EndPoint remoteEndPoint = null;
            try
            {
-                remoteEndPoint = clientSocket.RemoteEndPoint.ToString();
+                remoteEndPoint = clientSocket.RemoteEndPoint;
                _logger.Verbose("TCP client '{0}' accepted (Local endpoint={1})", remoteEndPoint, _localEndPoint);
@@ -12,10 +12,7 @@ public static class MqttConnAckPacketFactory
 {
    public static MqttConnAckPacket Create(ValidatingConnectionEventArgs validatingConnectionEventArgs)
    {
-        if (validatingConnectionEventArgs == null)
+        ArgumentNullException.ThrowIfNull(validatingConnectionEventArgs);
        {
            throw new ArgumentNullException(nameof(validatingConnectionEventArgs));
        }
        var connAckPacket = new MqttConnAckPacket
        {
@@ -11,15 +11,8 @@ public static class MqttPubAckPacketFactory
 {
    public static MqttPubAckPacket Create(MqttPublishPacket publishPacket, DispatchApplicationMessageResult dispatchApplicationMessageResult)
    {
-        if (publishPacket == null)
+        ArgumentNullException.ThrowIfNull(publishPacket);
-        {
+        ArgumentNullException.ThrowIfNull(dispatchApplicationMessageResult);
            throw new ArgumentNullException(nameof(publishPacket));
        }
        if (dispatchApplicationMessageResult == null)
        {
            throw new ArgumentNullException(nameof(dispatchApplicationMessageResult));
        }
        var pubAckPacket = new MqttPubAckPacket
        {
@@ -11,10 +11,7 @@ public static class MqttPubCompPacketFactory
 {
    public static MqttPubCompPacket Create(MqttPubRelPacket pubRelPacket, MqttApplicationMessageReceivedReasonCode reasonCode)
    {
-        if (pubRelPacket == null)
+        ArgumentNullException.ThrowIfNull(pubRelPacket);
        {
            throw new ArgumentNullException(nameof(pubRelPacket));
        }
        return new MqttPubCompPacket
        {
@@ -11,10 +11,7 @@ public static class MqttPubRecPacketFactory
 {
    public static MqttPacket Create(MqttPublishPacket publishPacket, DispatchApplicationMessageResult dispatchApplicationMessageResult)
    {
-        if (publishPacket == null)
+        ArgumentNullException.ThrowIfNull(publishPacket);
        {
            throw new ArgumentNullException(nameof(publishPacket));
        }
        var pubRecPacket = new MqttPubRecPacket
        {
@@ -11,10 +11,7 @@ public static class MqttPubRelPacketFactory
 {
    public static MqttPubRelPacket Create(MqttPubRecPacket pubRecPacket, MqttApplicationMessageReceivedReasonCode reasonCode)
    {
-        if (pubRecPacket == null)
+        ArgumentNullException.ThrowIfNull(pubRecPacket);
        {
            throw new ArgumentNullException(nameof(pubRecPacket));
        }
        return new MqttPubRelPacket
        {
@@ -11,10 +11,7 @@ public static class MqttPublishPacketFactory
 {
    public static MqttPublishPacket Create(MqttConnectPacket connectPacket)
    {
-        if (connectPacket == null)
+        ArgumentNullException.ThrowIfNull(connectPacket);
        {
            throw new ArgumentNullException(nameof(connectPacket));
        }
        if (!connectPacket.WillFlag)
        {
@@ -46,10 +43,7 @@ public static class MqttPublishPacketFactory
    public static MqttPublishPacket Create(MqttApplicationMessage applicationMessage)
    {
-        if (applicationMessage == null)
+        ArgumentNullException.ThrowIfNull(applicationMessage);
        {
            throw new ArgumentNullException(nameof(applicationMessage));
        }
        // Copy all values to their matching counterparts.
        // The not supported values in MQTT 3.1.1 are not serialized (excluded) later.
@@ -75,10 +69,7 @@ public static class MqttPublishPacketFactory
    public static MqttPublishPacket Create(MqttRetainedMessageMatch retainedMessage)
    {
-        if (retainedMessage == null)
+        ArgumentNullException.ThrowIfNull(retainedMessage);
        {
            throw new ArgumentNullException(nameof(retainedMessage));
        }
        var publishPacket = Create(retainedMessage.ApplicationMessage);
        publishPacket.QualityOfServiceLevel = retainedMessage.SubscriptionQualityOfServiceLevel;
@@ -10,15 +10,8 @@ public static class MqttSubAckPacketFactory
 {
    public static MqttSubAckPacket Create(MqttSubscribePacket subscribePacket, SubscribeResult subscribeResult)
    {
-        if (subscribePacket == null)
+        ArgumentNullException.ThrowIfNull(subscribePacket);
-        {
+        ArgumentNullException.ThrowIfNull(subscribeResult);
            throw new ArgumentNullException(nameof(subscribePacket));
        }
        if (subscribeResult == null)
        {
            throw new ArgumentNullException(nameof(subscribeResult));
        }
        var subAckPacket = new MqttSubAckPacket
        {
@@ -10,15 +10,8 @@ namespace MQTTnet.Server.Internal.Formatter
    {
        public static MqttUnsubAckPacket Create(MqttUnsubscribePacket unsubscribePacket, UnsubscribeResult unsubscribeResult)
        {
-            if (unsubscribePacket == null)
+            ArgumentNullException.ThrowIfNull(unsubscribePacket);
-            {
+            ArgumentNullException.ThrowIfNull(unsubscribeResult);
                throw new ArgumentNullException(nameof(unsubscribePacket));
            }
            if (unsubscribeResult == null)
            {
                throw new ArgumentNullException(nameof(unsubscribeResult));
            }
            var unsubAckPacket = new MqttUnsubAckPacket
            {
@@ -19,29 +19,22 @@ namespace MQTTnet.Server.Internal;
 public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification, IDisposable
 {
    readonly Dictionary<string, MqttConnectedClient> _clients = new(4096);
    readonly AsyncLock _createConnectionSyncRoot = new();
    readonly MqttServerEventContainer _eventContainer;
    readonly MqttNetSourceLogger _logger;
    readonly MqttServerOptions _options;
    readonly MqttRetainedMessagesManager _retainedMessagesManager;
    readonly IMqttNetLogger _rootLogger;
    readonly ReaderWriterLockSlim _sessionsManagementLock = new();
    // The _sessions dictionary contains all session, the _subscriberSessions hash set contains subscriber sessions only.
    // See the MqttSubscription object for a detailed explanation.
    readonly MqttSessionsStorage _sessionsStorage = new();
-    readonly HashSet<MqttSession> _subscriberSessions = new();
+    readonly HashSet<MqttSession> _subscriberSessions = [];
    public MqttClientSessionsManager(MqttServerOptions options, MqttRetainedMessagesManager retainedMessagesManager, MqttServerEventContainer eventContainer, IMqttNetLogger logger)
    {
-        if (logger == null)
+        ArgumentNullException.ThrowIfNull(logger);
        {
            throw new ArgumentNullException(nameof(logger));
        }
        _logger = logger.WithSource(nameof(MqttClientSessionsManager));
        _rootLogger = logger;
@@ -53,10 +46,7 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
    public async Task CloseAllConnections(MqttServerClientDisconnectOptions options)
    {
-        if (options == null)
+        ArgumentNullException.ThrowIfNull(options);
        {
            throw new ArgumentNullException(nameof(options));
        }
        List<MqttConnectedClient> connections;
        lock (_clients)
@@ -111,7 +101,7 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
        {
            if (_eventContainer.SessionDeletedEvent.HasHandlers && session != null)
            {
-                var eventArgs = new SessionDeletedEventArgs(clientId, session.Items);
+                var eventArgs = new SessionDeletedEventArgs(clientId, session.UserName, session.Items);
                await _eventContainer.SessionDeletedEvent.TryInvokeAsync(eventArgs, _logger).ConfigureAwait(false);
            }
        }
@@ -127,6 +117,7 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
    public async Task<DispatchApplicationMessageResult> DispatchApplicationMessage(
        string senderId,
        string senderUserName,
        IDictionary senderSessionItems,
        MqttApplicationMessage applicationMessage,
        CancellationToken cancellationToken)
@@ -140,7 +131,7 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
        // Allow the user to intercept application message...
        if (_eventContainer.InterceptingPublishEvent.HasHandlers)
        {
-            var interceptingPublishEventArgs = new InterceptingPublishEventArgs(applicationMessage, cancellationToken, senderId, senderSessionItems);
+            var interceptingPublishEventArgs = new InterceptingPublishEventArgs(applicationMessage, cancellationToken, senderId, senderUserName, senderSessionItems);
            if (string.IsNullOrEmpty(interceptingPublishEventArgs.ApplicationMessage.Topic))
            {
                // This can happen if a topic alias us used but the topic is
@@ -320,6 +311,25 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
        return Task.FromResult((IList<MqttClientStatus>)result);
    }
    public Task<MqttSessionStatus> GetSessionStatus(string id)
    {
        _sessionsManagementLock.EnterReadLock();
        try
        {
            if (!_sessionsStorage.TryGetSession(id, out var session))
            {
                throw new InvalidOperationException($"Session with ID '{id}' not found.");
            }
            var sessionStatus = new MqttSessionStatus(session);
            return Task.FromResult(sessionStatus);
        }
        finally
        {
            _sessionsManagementLock.ExitReadLock();
        }
    }
    public Task<IList<MqttSessionStatus>> GetSessionsStatus()
    {
        var result = new List<MqttSessionStatus>();
@@ -354,7 +364,7 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
                return;
            }
-            var validatingConnectionEventArgs = await ValidateConnection(connectPacket, channelAdapter).ConfigureAwait(false);
+            var validatingConnectionEventArgs = await ValidateConnection(connectPacket, channelAdapter, cancellationToken).ConfigureAwait(false);
            var connAckPacket = MqttConnAckPacketFactory.Create(validatingConnectionEventArgs);
            if (validatingConnectionEventArgs.ReasonCode != MqttConnectReasonCode.Success)
@@ -371,7 +381,11 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
            if (_eventContainer.ClientConnectedEvent.HasHandlers)
            {
-                var eventArgs = new ClientConnectedEventArgs(connectPacket, channelAdapter.PacketFormatterAdapter.ProtocolVersion, channelAdapter.Endpoint, connectedClient.Session.Items);
+                var eventArgs = new ClientConnectedEventArgs(
                    connectPacket,
                    channelAdapter.PacketFormatterAdapter.ProtocolVersion,
                    channelAdapter.RemoteEndPoint,
                    connectedClient.Session.Items);
                await _eventContainer.ClientConnectedEvent.TryInvokeAsync(eventArgs, _logger).ConfigureAwait(false);
            }
@@ -409,12 +423,17 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
                    }
                }
-                var endpoint = connectedClient.Endpoint;
+                var endpoint = connectedClient.RemoteEndPoint;
                if (connectedClient.Id != null && !connectedClient.IsTakenOver && _eventContainer.ClientDisconnectedEvent.HasHandlers)
                {
                    var disconnectType = connectedClient.DisconnectPacket != null ? MqttClientDisconnectType.Clean : MqttClientDisconnectType.NotClean;
-                    var eventArgs = new ClientDisconnectedEventArgs(connectedClient.Id, connectedClient.DisconnectPacket, disconnectType, endpoint, connectedClient.Session.Items);
+                    var eventArgs = new ClientDisconnectedEventArgs(
                        connectedClient.ConnectPacket,
                        connectedClient.DisconnectPacket,
                        disconnectType,
                        endpoint,
                        connectedClient.Session.Items);
                    await _eventContainer.ClientDisconnectedEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
                }
@@ -481,15 +500,8 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
    public async Task SubscribeAsync(string clientId, ICollection<MqttTopicFilter> topicFilters)
    {
-        if (clientId == null)
+        ArgumentNullException.ThrowIfNull(clientId);
-        {
+        ArgumentNullException.ThrowIfNull(topicFilters);
            throw new ArgumentNullException(nameof(clientId));
        }
        if (topicFilters == null)
        {
            throw new ArgumentNullException(nameof(topicFilters));
        }
        var fakeSubscribePacket = new MqttSubscribePacket();
        fakeSubscribePacket.TopicFilters.AddRange(topicFilters);
@@ -510,15 +522,8 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
    public Task UnsubscribeAsync(string clientId, ICollection<string> topicFilters)
    {
-        if (clientId == null)
+        ArgumentNullException.ThrowIfNull(clientId);
-        {
+        ArgumentNullException.ThrowIfNull(topicFilters);
            throw new ArgumentNullException(nameof(clientId));
        }
        if (topicFilters == null)
        {
            throw new ArgumentNullException(nameof(topicFilters));
        }
        var fakeUnsubscribePacket = new MqttUnsubscribePacket();
        fakeUnsubscribePacket.TopicFilters.AddRange(topicFilters);
@@ -611,7 +616,12 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
                if (_eventContainer.ClientDisconnectedEvent.HasHandlers)
                {
-                    var eventArgs = new ClientDisconnectedEventArgs(oldConnectedClient.Id, null, MqttClientDisconnectType.Takeover, oldConnectedClient.Endpoint, oldConnectedClient.Session.Items);
+                    var eventArgs = new ClientDisconnectedEventArgs(
                        oldConnectedClient.ConnectPacket,
                        null,
                        MqttClientDisconnectType.Takeover,
                        oldConnectedClient.RemoteEndPoint,
                        oldConnectedClient.Session.Items);
                    await _eventContainer.ClientDisconnectedEvent.TryInvokeAsync(eventArgs, _logger).ConfigureAwait(false);
                }
@@ -675,14 +685,14 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
        }
        catch (OperationCanceledException)
        {
-            _logger.Warning("Client '{0}': Connected but did not sent a CONNECT packet.", channelAdapter.Endpoint);
+            _logger.Warning("Client '{0}': Connected but did not sent a CONNECT packet.", channelAdapter.RemoteEndPoint);
        }
        catch (MqttCommunicationTimedOutException)
        {
-            _logger.Warning("Client '{0}': Connected but did not sent a CONNECT packet.", channelAdapter.Endpoint);
+            _logger.Warning("Client '{0}': Connected but did not sent a CONNECT packet.", channelAdapter.RemoteEndPoint);
        }
-        _logger.Warning("Client '{0}': First received packet was no 'CONNECT' packet [MQTT-3.1.0-1].", channelAdapter.Endpoint);
+        _logger.Warning("Client '{0}': First received packet was no 'CONNECT' packet [MQTT-3.1.0-1].", channelAdapter.RemoteEndPoint);
        return null;
    }
@@ -730,11 +740,11 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
        }
    }
-    async Task<ValidatingConnectionEventArgs> ValidateConnection(MqttConnectPacket connectPacket, IMqttChannelAdapter channelAdapter)
+    async Task<ValidatingConnectionEventArgs> ValidateConnection(MqttConnectPacket connectPacket, IMqttChannelAdapter channelAdapter, CancellationToken cancellationToken)
    {
        // TODO: Load session items from persisted sessions in the future.
        var sessionItems = new ConcurrentDictionary<object, object>();
-        var eventArgs = new ValidatingConnectionEventArgs(connectPacket, channelAdapter, sessionItems);
+        var eventArgs = new ValidatingConnectionEventArgs(connectPacket, channelAdapter, sessionItems, cancellationToken);
        await _eventContainer.ValidatingConnectionEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
        // Check the client ID and set a random one if supported.
@@ -50,10 +50,7 @@ namespace MQTTnet.Server.Internal
        public void HandleReceivedPacket(MqttPacket packet)
        {
-            if (packet == null)
+            ArgumentNullException.ThrowIfNull(packet);
            {
                throw new ArgumentNullException(nameof(packet));
            }
            // This class is tracking all values from Clients perspective!
            LastPacketSentTimestamp = DateTime.UtcNow;
@@ -74,10 +71,7 @@ namespace MQTTnet.Server.Internal
        public void HandleSentPacket(MqttPacket packet)
        {
-            if (packet == null)
+            ArgumentNullException.ThrowIfNull(packet);
            {
                throw new ArgumentNullException(nameof(packet));
            }
            // This class is tracking all values from Clients perspective!
            LastPacketReceivedTimestamp = DateTime.UtcNow;
@@ -161,10 +161,7 @@ namespace MQTTnet.Server.Internal
        public async Task<SubscribeResult> Subscribe(MqttSubscribePacket subscribePacket, CancellationToken cancellationToken)
        {
-            if (subscribePacket == null)
+            ArgumentNullException.ThrowIfNull(subscribePacket);
            {
                throw new ArgumentNullException(nameof(subscribePacket));
            }
            var retainedApplicationMessages = await _retainedMessagesManager.GetMessages().ConfigureAwait(false);
            var result = new SubscribeResult(subscribePacket.TopicFilters.Count);
@@ -212,7 +209,7 @@ namespace MQTTnet.Server.Internal
            {
                foreach (var finalTopicFilter in finalTopicFilters)
                {
-                    var eventArgs = new ClientSubscribedTopicEventArgs(_session.Id, finalTopicFilter, _session.Items);
+                    var eventArgs = new ClientSubscribedTopicEventArgs(_session.Id, _session.UserName, finalTopicFilter, _session.Items);
                    await _eventContainer.ClientSubscribedTopicEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
                }
            }
@@ -222,10 +219,7 @@ namespace MQTTnet.Server.Internal
        public async Task<UnsubscribeResult> Unsubscribe(MqttUnsubscribePacket unsubscribePacket, CancellationToken cancellationToken)
        {
-            if (unsubscribePacket == null)
+            ArgumentNullException.ThrowIfNull(unsubscribePacket);
            {
                throw new ArgumentNullException(nameof(unsubscribePacket));
            }
            var result = new UnsubscribeResult();
@@ -303,7 +297,7 @@ namespace MQTTnet.Server.Internal
            {
                foreach (var topicFilter in unsubscribePacket.TopicFilters)
                {
-                    var eventArgs = new ClientUnsubscribedTopicEventArgs(_session.Id, topicFilter, _session.Items);
+                    var eventArgs = new ClientUnsubscribedTopicEventArgs(_session.Id, _session.UserName, topicFilter, _session.Items);
                    await _eventContainer.ClientUnsubscribedTopicEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
                }
            }
@@ -466,7 +460,7 @@ namespace MQTTnet.Server.Internal
            List<MqttUserProperty> userProperties,
            CancellationToken cancellationToken)
        {
-            var eventArgs = new InterceptingSubscriptionEventArgs(cancellationToken, _session.Id, new MqttSessionStatus(_session), topicFilter, userProperties);
+            var eventArgs = new InterceptingSubscriptionEventArgs(cancellationToken, _session.Id, _session.UserName, new MqttSessionStatus(_session), topicFilter, userProperties);
            if (topicFilter.QualityOfServiceLevel == MqttQualityOfServiceLevel.AtMostOnce)
            {
@@ -499,7 +493,7 @@ namespace MQTTnet.Server.Internal
            List<MqttUserProperty> userProperties,
            CancellationToken cancellationToken)
        {
-            var clientUnsubscribingTopicEventArgs = new InterceptingUnsubscriptionEventArgs(cancellationToken, _session.Id, _session.Items, topicFilter, userProperties)
+            var clientUnsubscribingTopicEventArgs = new InterceptingUnsubscriptionEventArgs(cancellationToken, _session.Id, _session.UserName, _session.Items, topicFilter, userProperties)
            {
                Response =
                {
@@ -2,6 +2,7 @@
 // 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.Net;
 using MQTTnet.Adapter;
 using MQTTnet.Diagnostics.Logger;
 using MQTTnet.Exceptions;
@@ -45,13 +46,10 @@ public sealed class MqttConnectedClient : IDisposable
        ConnectPacket = connectPacket ?? throw new ArgumentNullException(nameof(connectPacket));
        ChannelAdapter = channelAdapter ?? throw new ArgumentNullException(nameof(channelAdapter));
-        Endpoint = channelAdapter.Endpoint;
+        RemoteEndPoint = channelAdapter.RemoteEndPoint;
        Session = session ?? throw new ArgumentNullException(nameof(session));
-        if (logger == null)
+        ArgumentNullException.ThrowIfNull(logger);
        {
            throw new ArgumentNullException(nameof(logger));
        }
        _logger = logger.WithSource(nameof(MqttConnectedClient));
    }
@@ -62,18 +60,20 @@ public sealed class MqttConnectedClient : IDisposable
    public MqttDisconnectPacket DisconnectPacket { get; private set; }
    public string Endpoint { get; }
    public string Id => ConnectPacket.ClientId;
    public bool IsRunning { get; private set; }
    public bool IsTakenOver { get; set; }
    public EndPoint RemoteEndPoint { get; }
    public MqttSession Session { get; }
    public MqttClientStatistics Statistics { get; } = new();
    public string UserName => ConnectPacket.Username;
    public void Dispose()
    {
        _cancellationToken?.Dispose();
@@ -119,7 +119,7 @@ public sealed class MqttConnectedClient : IDisposable
            var willPublishPacket = MqttPublishPacketFactory.Create(Session.LatestConnectPacket);
            var willApplicationMessage = MqttApplicationMessageFactory.Create(willPublishPacket);
-            _ = _sessionsManager.DispatchApplicationMessage(Id, Session.Items, willApplicationMessage, CancellationToken.None);
+            _ = _sessionsManager.DispatchApplicationMessage(Id, UserName, Session.Items, willApplicationMessage, CancellationToken.None);
            Session.WillMessageSent = true;
            _logger.Info("Client '{0}': Published will message", Id);
@@ -176,7 +176,7 @@ public sealed class MqttConnectedClient : IDisposable
    {
        if (_eventContainer.ClientAcknowledgedPublishPacketEvent.HasHandlers)
        {
-            var eventArgs = new ClientAcknowledgedPublishPacketEventArgs(Id, Session.Items, publishPacket, acknowledgePacket);
+            var eventArgs = new ClientAcknowledgedPublishPacketEventArgs(Id, UserName, Session.Items, publishPacket, acknowledgePacket);
            return _eventContainer.ClientAcknowledgedPublishPacketEvent.TryInvokeAsync(eventArgs, _logger);
        }
@@ -219,7 +219,8 @@ public sealed class MqttConnectedClient : IDisposable
        var applicationMessage = MqttApplicationMessageFactory.Create(publishPacket);
-        var dispatchApplicationMessageResult = await _sessionsManager.DispatchApplicationMessage(Id, Session.Items, applicationMessage, cancellationToken).ConfigureAwait(false);
+        var dispatchApplicationMessageResult =
            await _sessionsManager.DispatchApplicationMessage(Id, UserName, Session.Items, applicationMessage, cancellationToken).ConfigureAwait(false);
        if (dispatchApplicationMessageResult.CloseConnection)
        {
@@ -341,7 +342,7 @@ public sealed class MqttConnectedClient : IDisposable
            return packet;
        }
-        var interceptingPacketEventArgs = new InterceptingPacketEventArgs(cancellationToken, Id, Endpoint, packet, Session.Items);
+        var interceptingPacketEventArgs = new InterceptingPacketEventArgs(cancellationToken, Id, UserName, RemoteEndPoint, packet, Session.Items);
        await _eventContainer.InterceptingOutboundPacketEvent.InvokeAsync(interceptingPacketEventArgs).ConfigureAwait(false);
        if (!interceptingPacketEventArgs.ProcessPacket || packet == null)
@@ -387,7 +388,7 @@ public sealed class MqttConnectedClient : IDisposable
                if (_eventContainer.InterceptingInboundPacketEvent.HasHandlers)
                {
-                    var interceptingPacketEventArgs = new InterceptingPacketEventArgs(cancellationToken, Id, Endpoint, currentPacket, Session.Items);
+                    var interceptingPacketEventArgs = new InterceptingPacketEventArgs(cancellationToken, Id, UserName, RemoteEndPoint, currentPacket, Session.Items);
                    await _eventContainer.InterceptingInboundPacketEvent.InvokeAsync(interceptingPacketEventArgs).ConfigureAwait(false);
                    currentPacket = interceptingPacketEventArgs.Packet;
                    processPacket = interceptingPacketEventArgs.ProcessPacket;
@@ -563,10 +564,8 @@ public sealed class MqttConnectedClient : IDisposable
            var disconnectPacket = MqttDisconnectPacketFactory.Create(options);
-            using (var timeout = new CancellationTokenSource(_serverOptions.DefaultCommunicationTimeout))
+            using var timeout = new CancellationTokenSource(_serverOptions.DefaultCommunicationTimeout);
-            {
+            await SendPacketAsync(disconnectPacket, timeout.Token).ConfigureAwait(false);
                await SendPacketAsync(disconnectPacket, timeout.Token).ConfigureAwait(false);
            }
        }
        catch (Exception exception)
        {
@@ -2,6 +2,7 @@
 // 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.ObjectModel;
 using MQTTnet.Diagnostics.Logger;
 using MQTTnet.Internal;
@@ -19,8 +20,7 @@ namespace MQTTnet.Server.Internal
        {
            _eventContainer = eventContainer ?? throw new ArgumentNullException(nameof(eventContainer));
-            if (logger == null)
+            ArgumentNullException.ThrowIfNull(logger);
                throw new ArgumentNullException(nameof(logger));
            _logger = logger.WithSource(nameof(MqttRetainedMessagesManager));
        }
@@ -53,10 +53,7 @@ namespace MQTTnet.Server.Internal
        public async Task UpdateMessage(string clientId, MqttApplicationMessage applicationMessage)
        {
-            if (applicationMessage == null)
+            ArgumentNullException.ThrowIfNull(applicationMessage);
            {
                throw new ArgumentNullException(nameof(applicationMessage));
            }
            try
            {
@@ -27,10 +27,7 @@ namespace MQTTnet.Server.Internal
            _options = options ?? throw new ArgumentNullException(nameof(options));
            _sessionsManager = sessionsManager ?? throw new ArgumentNullException(nameof(sessionsManager));
-            if (logger == null)
+            ArgumentNullException.ThrowIfNull(logger);
            {
                throw new ArgumentNullException(nameof(logger));
            }
            _logger = logger.WithSource(nameof(MqttServerKeepAliveMonitor));
        }
@@ -53,6 +53,8 @@ public sealed class MqttSession : IDisposable
    public string Id => _connectPacket.ClientId;
    public string UserName => _connectPacket.Username;
    public IDictionary Items { get; }
    public MqttConnectPacket LatestConnectPacket { get; set; }
@@ -34,10 +34,7 @@ namespace MQTTnet.Server.Internal
        public bool TryGetSession(string id, out MqttSession session)
        {
-            if (id == null)
+            ArgumentNullException.ThrowIfNull(id);
            {
                throw new ArgumentNullException(nameof(id));
            }
            if (!_sessions.TryGetValue(id, out session))
            {
@@ -63,10 +60,7 @@ namespace MQTTnet.Server.Internal
        public bool TryRemoveSession(string id, out MqttSession session)
        {
-            if (id == null)
+            ArgumentNullException.ThrowIfNull(id);
            {
                throw new ArgumentNullException(nameof(id));
            }
            if (_sessions.TryGetValue(id, out session))
            {
@@ -79,10 +73,7 @@ namespace MQTTnet.Server.Internal
        public void UpdateSession(string id, MqttSession session)
        {
-            if (id == null)
+            ArgumentNullException.ThrowIfNull(id);
            {
                throw new ArgumentNullException(nameof(id));
            }
            _sessions[id] = session;
        }
@@ -31,10 +31,7 @@ public class MqttServer : Disposable
    {
        _options = options ?? throw new ArgumentNullException(nameof(options));
-        if (adapters == null)
+        ArgumentNullException.ThrowIfNull(adapters);
        {
            throw new ArgumentNullException(nameof(adapters));
        }
        _adapters = adapters.ToList();
@@ -202,15 +199,8 @@ public class MqttServer : Disposable
    public Task DisconnectClientAsync(string id, MqttServerClientDisconnectOptions options)
    {
-        if (id == null)
+        ArgumentNullException.ThrowIfNull(id);
-        {
+        ArgumentNullException.ThrowIfNull(options);
            throw new ArgumentNullException(nameof(id));
        }
        if (options == null)
        {
            throw new ArgumentNullException(nameof(options));
        }
        ThrowIfNotStarted();
@@ -226,10 +216,7 @@ public class MqttServer : Disposable
    public Task<MqttApplicationMessage> GetRetainedMessageAsync(string topic)
    {
-        if (topic == null)
+        ArgumentNullException.ThrowIfNull(topic);
        {
            throw new ArgumentNullException(nameof(topic));
        }
        ThrowIfNotStarted();
@@ -250,17 +237,17 @@ public class MqttServer : Disposable
        return _clientSessionsManager.GetSessionsStatus();
    }
    public Task<MqttSessionStatus> GetSessionAsync(string id)
    {
        ThrowIfNotStarted();
        return _clientSessionsManager.GetSessionStatus(id);
    }
    public Task InjectApplicationMessage(InjectedMqttApplicationMessage injectedApplicationMessage, CancellationToken cancellationToken = default)
    {
-        if (injectedApplicationMessage == null)
+        ArgumentNullException.ThrowIfNull(injectedApplicationMessage);
-        {
+        ArgumentNullException.ThrowIfNull(injectedApplicationMessage.ApplicationMessage);
            throw new ArgumentNullException(nameof(injectedApplicationMessage));
        }
        if (injectedApplicationMessage.ApplicationMessage == null)
        {
            throw new ArgumentNullException(nameof(injectedApplicationMessage.ApplicationMessage));
        }
        MqttTopicValidator.ThrowIfInvalid(injectedApplicationMessage.ApplicationMessage.Topic);
@@ -275,6 +262,7 @@ public class MqttServer : Disposable
        return _clientSessionsManager.DispatchApplicationMessage(
            injectedApplicationMessage.SenderClientId,
            injectedApplicationMessage.SenderUserName,
            sessionItems,
            injectedApplicationMessage.ApplicationMessage,
            cancellationToken);
@@ -306,10 +294,7 @@ public class MqttServer : Disposable
    public async Task StopAsync(MqttServerStopOptions options)
    {
-        if (options == null)
+        ArgumentNullException.ThrowIfNull(options);
        {
            throw new ArgumentNullException(nameof(options));
        }
        try
        {
@@ -343,15 +328,8 @@ public class MqttServer : Disposable
    public Task SubscribeAsync(string clientId, ICollection<MqttTopicFilter> topicFilters)
    {
-        if (clientId == null)
+        ArgumentNullException.ThrowIfNull(clientId);
-        {
+        ArgumentNullException.ThrowIfNull(topicFilters);
            throw new ArgumentNullException(nameof(clientId));
        }
        if (topicFilters == null)
        {
            throw new ArgumentNullException(nameof(topicFilters));
        }
        foreach (var topicFilter in topicFilters)
        {
@@ -366,15 +344,8 @@ public class MqttServer : Disposable
    public Task UnsubscribeAsync(string clientId, ICollection<string> topicFilters)
    {
-        if (clientId == null)
+        ArgumentNullException.ThrowIfNull(clientId);
-        {
+        ArgumentNullException.ThrowIfNull(topicFilters);
            throw new ArgumentNullException(nameof(clientId));
        }
        if (topicFilters == null)
        {
            throw new ArgumentNullException(nameof(topicFilters));
        }
        ThrowIfDisposed();
        ThrowIfNotStarted();
@@ -384,10 +355,7 @@ public class MqttServer : Disposable
    public Task UpdateRetainedMessageAsync(MqttApplicationMessage retainedMessage)
    {
-        if (retainedMessage == null)
+        ArgumentNullException.ThrowIfNull(retainedMessage);
        {
            throw new ArgumentNullException(nameof(retainedMessage));
        }
        ThrowIfDisposed();
        ThrowIfNotStarted();
@@ -13,10 +13,7 @@ public static class MqttServerExtensions
 {
    public static Task DisconnectClientAsync(this MqttServer server, string id, MqttDisconnectReasonCode reasonCode = MqttDisconnectReasonCode.NormalDisconnection)
    {
-        if (server == null)
+        ArgumentNullException.ThrowIfNull(server);
        {
            throw new ArgumentNullException(nameof(server));
        }
        return server.DisconnectClientAsync(id, new MqttServerClientDisconnectOptions { ReasonCode = reasonCode });
    }
@@ -28,15 +25,8 @@ public static class MqttServerExtensions
        MqttQualityOfServiceLevel qualityOfServiceLevel = MqttQualityOfServiceLevel.AtMostOnce,
        bool retain = false)
    {
-        if (server == null)
+        ArgumentNullException.ThrowIfNull(server);
-        {
+        ArgumentNullException.ThrowIfNull(topic);
            throw new ArgumentNullException(nameof(server));
        }
        if (topic == null)
        {
            throw new ArgumentNullException(nameof(topic));
        }
        var payloadBuffer = EmptyBuffer.Array;
        if (payload is string stringPayload)
@@ -57,50 +47,25 @@ public static class MqttServerExtensions
    public static Task StopAsync(this MqttServer server)
    {
-        if (server == null)
+        ArgumentNullException.ThrowIfNull(server);
        {
            throw new ArgumentNullException(nameof(server));
        }
        return server.StopAsync(new MqttServerStopOptions());
    }
    public static Task SubscribeAsync(this MqttServer server, string clientId, params MqttTopicFilter[] topicFilters)
    {
-        if (server == null)
+        ArgumentNullException.ThrowIfNull(server);
-        {
+        ArgumentNullException.ThrowIfNull(clientId);
-            throw new ArgumentNullException(nameof(server));
+        ArgumentNullException.ThrowIfNull(topicFilters);
        }
        if (clientId == null)
        {
            throw new ArgumentNullException(nameof(clientId));
        }
        if (topicFilters == null)
        {
            throw new ArgumentNullException(nameof(topicFilters));
        }
        return server.SubscribeAsync(clientId, topicFilters);
    }
    public static Task SubscribeAsync(this MqttServer server, string clientId, string topic)
    {
-        if (server == null)
+        ArgumentNullException.ThrowIfNull(server);
-        {
+        ArgumentNullException.ThrowIfNull(clientId);
-            throw new ArgumentNullException(nameof(server));
+        ArgumentNullException.ThrowIfNull(topic);
        }
        if (clientId == null)
        {
            throw new ArgumentNullException(nameof(clientId));
        }
        if (topic == null)
        {
            throw new ArgumentNullException(nameof(topic));
        }
        var topicFilters = new MqttTopicFilterBuilder().WithTopic(topic).Build();
        return server.SubscribeAsync(clientId, topicFilters);
@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 using MQTTnet.Diagnostics.Logger;
 using MQTTnet.Server.EnhancedAuthentication;
 using MQTTnet.Server.Internal.Adapter;
 namespace MQTTnet.Server;
@@ -32,6 +33,11 @@ public sealed class MqttServerFactory
        return new MqttApplicationMessageBuilder();
    }
    public ExchangeEnhancedAuthenticationOptionsFactory CreateExchangeExtendedAuthenticationOptionsBuilder()
    {
        return new ExchangeEnhancedAuthenticationOptionsFactory();
    }
    public MqttServer CreateMqttServer(MqttServerOptions options)
    {
        return CreateMqttServer(options, DefaultLogger);
@@ -39,10 +45,7 @@ public sealed class MqttServerFactory
    public MqttServer CreateMqttServer(MqttServerOptions options, IMqttNetLogger logger)
    {
-        if (logger == null)
+        ArgumentNullException.ThrowIfNull(logger);
        {
            throw new ArgumentNullException(nameof(logger));
        }
        var serverAdapters = DefaultServerAdapters.Select(a => a.Invoke(this));
        return CreateMqttServer(options, serverAdapters, logger);
@@ -50,25 +53,15 @@ public sealed class MqttServerFactory
    public MqttServer CreateMqttServer(MqttServerOptions options, IEnumerable<IMqttServerAdapter> serverAdapters, IMqttNetLogger logger)
    {
-        if (serverAdapters == null)
+        ArgumentNullException.ThrowIfNull(serverAdapters);
-        {
+        ArgumentNullException.ThrowIfNull(logger);
            throw new ArgumentNullException(nameof(serverAdapters));
        }
        if (logger == null)
        {
            throw new ArgumentNullException(nameof(logger));
        }
        return new MqttServer(options, serverAdapters, logger);
    }
    public MqttServer CreateMqttServer(MqttServerOptions options, IEnumerable<IMqttServerAdapter> serverAdapters)
    {
-        if (serverAdapters == null)
+        ArgumentNullException.ThrowIfNull(serverAdapters);
        {
            throw new ArgumentNullException(nameof(serverAdapters));
        }
        return new MqttServer(options, serverAdapters, DefaultLogger);
    }
@@ -2,38 +2,35 @@
 // 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.Server;
-namespace MQTTnet.Server
+public sealed class MqttServerOptions
 {
-    public sealed class MqttServerOptions
+    public TimeSpan DefaultCommunicationTimeout { get; set; } = TimeSpan.FromSeconds(100);
    {
        public TimeSpan DefaultCommunicationTimeout { get; set; } = TimeSpan.FromSeconds(100);
-        public MqttServerTcpEndpointOptions DefaultEndpointOptions { get; } = new MqttServerTcpEndpointOptions();
+    public MqttServerTcpEndpointOptions DefaultEndpointOptions { get; } = new();
-        public bool EnablePersistentSessions { get; set; }
+    public bool EnablePersistentSessions { get; set; }
-        public MqttServerKeepAliveOptions KeepAliveOptions { get; } = new MqttServerKeepAliveOptions();
+    public MqttServerKeepAliveOptions KeepAliveOptions { get; } = new();
-        public int MaxPendingMessagesPerClient { get; set; } = 250;
+    public int MaxPendingMessagesPerClient { get; set; } = 1000;
-        public MqttPendingMessagesOverflowStrategy PendingMessagesOverflowStrategy { get; set; } = MqttPendingMessagesOverflowStrategy.DropOldestQueuedMessage;
+    public MqttPendingMessagesOverflowStrategy PendingMessagesOverflowStrategy { get; set; } = MqttPendingMessagesOverflowStrategy.DropOldestQueuedMessage;
-        public MqttServerTlsTcpEndpointOptions TlsEndpointOptions { get; } = new MqttServerTlsTcpEndpointOptions();
+    public MqttServerTlsTcpEndpointOptions TlsEndpointOptions { get; } = new();
-        /// <summary>
+    /// <summary>
-        ///     Gets or sets the default and initial size of the packet write buffer.
+    ///     Gets or sets the default and initial size of the packet write buffer.
-        ///     It is recommended to set this to a value close to the usual expected packet size * 1.5.
+    ///     It is recommended to set this to a value close to the usual expected packet size * 1.5.
-        ///     Do not change this value when no memory issues are experienced.
+    ///     Do not change this value when no memory issues are experienced.
-        /// </summary>
+    /// </summary>
-        public int WriterBufferSize { get; set; } = 4096;
+    public int WriterBufferSize { get; set; } = 4096;
-        /// <summary>
+    /// <summary>
-        ///     Gets or sets the maximum size of the buffer writer. The writer will reduce its internal buffer
+    ///     Gets or sets the maximum size of the buffer writer. The writer will reduce its internal buffer
-        ///     to this value after serializing a packet.
+    ///     to this value after serializing a packet.
-        ///     Do not change this value when no memory issues are experienced.
+    ///     Do not change this value when no memory issues are experienced.
-        /// </summary>
+    /// </summary>
-        public int WriterBufferSizeMax { get; set; } = 65535;
+    public int WriterBufferSizeMax { get; set; } = 65535;
    }
 }
@@ -180,10 +180,7 @@ namespace MQTTnet.Server
        public MqttServerOptionsBuilder WithEncryptionCertificate(byte[] value, IMqttServerCertificateCredentials credentials = null)
        {
-            if (value == null)
+            ArgumentNullException.ThrowIfNull(value);
            {
                throw new ArgumentNullException(nameof(value));
            }
            _options.TlsEndpointOptions.CertificateProvider = new BlobCertificateProvider(value)
            {
@@ -195,10 +192,7 @@ namespace MQTTnet.Server
        public MqttServerOptionsBuilder WithEncryptionCertificate(X509Certificate2 certificate)
        {
-            if (certificate == null)
+            ArgumentNullException.ThrowIfNull(certificate);
            {
                throw new ArgumentNullException(nameof(certificate));
            }
            _options.TlsEndpointOptions.CertificateProvider = new X509CertificateProvider(certificate);
            return this;
@@ -206,10 +200,7 @@ namespace MQTTnet.Server
        public MqttServerOptionsBuilder WithEncryptionCertificate(ICertificateProvider certificateProvider)
        {
-            if (certificateProvider == null)
+            ArgumentNullException.ThrowIfNull(certificateProvider);
            {
                throw new ArgumentNullException(nameof(certificateProvider));
            }
            _options.TlsEndpointOptions.CertificateProvider = certificateProvider;
@@ -22,7 +22,11 @@ namespace MQTTnet.Server
        public bool CheckCertificateRevocation { get; set; }
-        public SslProtocols SslProtocol { get; set; } = SslProtocols.Tls12;
+        /// <summary>
        /// The default value is SslProtocols.None, which allows the operating system to choose the best protocol to use, and to block protocols that are not secure.
        /// </summary>
        /// <seealso href="https://learn.microsoft.com/en-us/dotnet/api/system.security.authentication.sslprotocols">SslProtocols</seealso>       
        public SslProtocols SslProtocol { get; set; } = SslProtocols.None;
        public System.Net.Security.CipherSuitesPolicy CipherSuitesPolicy { get; set; }
    }
@@ -4,6 +4,7 @@
 using MQTTnet.Formatter;
 using MQTTnet.Server.Internal;
 using System.Net;
 namespace MQTTnet.Server;
@@ -22,7 +23,10 @@ public sealed class MqttClientStatus
    public DateTime ConnectedTimestamp => _client.Statistics.ConnectedTimestamp;
-    public string Endpoint => _client.Endpoint;
+    public EndPoint RemoteEndPoint => _client.RemoteEndPoint;
    [Obsolete("Use RemoteEndPoint instead.")]
    public string Endpoint => RemoteEndPoint?.ToString();
    /// <summary>
    ///     Gets or sets the client identifier.
@@ -50,10 +54,7 @@ public sealed class MqttClientStatus
    public Task DisconnectAsync(MqttServerClientDisconnectOptions options)
    {
-        if (options == null)
+        ArgumentNullException.ThrowIfNull(options);
        {
            throw new ArgumentNullException(nameof(options));
        }
        return _client.StopAsync(options);
    }
@@ -18,10 +18,7 @@ public static class MqttClientStatusExtensions
    public static Task DisconnectAsync(this MqttClientStatus clientStatus)
    {
-        if (clientStatus == null)
+        ArgumentNullException.ThrowIfNull(clientStatus);
        {
            throw new ArgumentNullException(nameof(clientStatus));
        }
        return clientStatus.DisconnectAsync(DefaultDisconnectOptions);
    }
@@ -42,10 +42,7 @@ public sealed class MqttSessionStatus
    public Task DeliverApplicationMessageAsync(MqttApplicationMessage applicationMessage)
    {
-        if (applicationMessage == null)
+        ArgumentNullException.ThrowIfNull(applicationMessage);
        {
            throw new ArgumentNullException(nameof(applicationMessage));
        }
        var packetBusItem = new MqttPacketBusItem(MqttPublishPacketFactory.Create(applicationMessage));
        _session.EnqueueDataPacket(packetBusItem);
@@ -55,10 +52,7 @@ public sealed class MqttSessionStatus
    public Task EnqueueApplicationMessageAsync(MqttApplicationMessage applicationMessage)
    {
-        if (applicationMessage == null)
+        ArgumentNullException.ThrowIfNull(applicationMessage);
        {
            throw new ArgumentNullException(nameof(applicationMessage));
        }
        _session.EnqueueDataPacket(new MqttPacketBusItem(MqttPublishPacketFactory.Create(applicationMessage)));
@@ -18,10 +18,7 @@ namespace MQTTnet.Server
        public MqttServerStopOptionsBuilder WithDefaultClientDisconnectOptions(Action<MqttServerClientDisconnectOptionsBuilder> builder)
        {
-            if (builder == null)
+            ArgumentNullException.ThrowIfNull(builder);
            {
                throw new ArgumentNullException(nameof(builder));
            }
            var optionsBuilder = new MqttServerClientDisconnectOptionsBuilder();
            builder.Invoke(optionsBuilder);
@@ -14,7 +14,7 @@ namespace MQTTnet.TestApp
        public static void ForwardToConsole(MqttNetEventLogger logger)
        {
-            if (logger == null) throw new ArgumentNullException(nameof(logger));
+            ArgumentNullException.ThrowIfNull(logger);
            logger.LogMessagePublished -= PrintToConsole;
            logger.LogMessagePublished += PrintToConsole;
@@ -43,7 +43,9 @@ namespace MQTTnet.TestApp
        {
            try
            {
-                var options = new MqttServerOptions();
+                var options = new MqttServerOptionsBuilder()
                    .WithDefaultEndpoint()
                    .Build();
                // Extend the timestamp for all messages from clients.
                // Protect several topics from being subscribed from every client.
@@ -3,16 +3,16 @@
 // See the LICENSE file in the project root for more information.
 using System;
-using System.Collections.Generic;
+using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using MQTTnet.Exceptions;
 using MQTTnet.Formatter;
 using MQTTnet.Internal;
 using MQTTnet.Packets;
 using MQTTnet.Protocol;
 using MQTTnet.Server;
 using MQTTnet.Server.EnhancedAuthentication;
 namespace MQTTnet.Tests.Clients.MqttClient
 {
@@ -24,10 +24,8 @@ namespace MQTTnet.Tests.Clients.MqttClient
        public async Task Connect_To_Invalid_Server_Port_Not_Opened()
        {
            var client = new MqttClientFactory().CreateMqttClient();
-            using (var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(5)))
+            using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(5));
-            {
+            await client.ConnectAsync(new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1", 12345).Build(), timeout.Token);
                await client.ConnectAsync(new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1", 12345).Build(), timeout.Token);
            }
        }
        [TestMethod]
@@ -35,10 +33,8 @@ namespace MQTTnet.Tests.Clients.MqttClient
        public async Task Connect_To_Invalid_Server_Wrong_IP()
        {
            var client = new MqttClientFactory().CreateMqttClient();
-            using (var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(2)))
+            using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(2));
-            {
+            await client.ConnectAsync(new MqttClientOptionsBuilder().WithTcpServer("1.2.3.4").Build(), timeout.Token);
                await client.ConnectAsync(new MqttClientOptionsBuilder().WithTcpServer("1.2.3.4").Build(), timeout.Token);
            }
        }
        [TestMethod]
@@ -53,179 +49,229 @@ namespace MQTTnet.Tests.Clients.MqttClient
        public async Task ConnectTimeout_Throws_Exception()
        {
            var factory = new MqttClientFactory();
-            using (var client = factory.CreateMqttClient())
+            using var client = factory.CreateMqttClient();
            var disconnectHandlerCalled = false;
            try
            {
-                var disconnectHandlerCalled = false;
+                client.DisconnectedAsync += _ =>
                try
                {
-                    client.DisconnectedAsync += args =>
+                    disconnectHandlerCalled = true;
-                    {
+                    return CompletedTask.Instance;
-                        disconnectHandlerCalled = true;
+                };
                        return CompletedTask.Instance;
                    };
-                    await client.ConnectAsync(new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1").Build());
+                await client.ConnectAsync(new MqttClientOptionsBuilder().WithTcpServer("127.0.0.1").Build());
-                    Assert.Fail("Must fail!");
+                Assert.Fail("Must fail!");
                }
                catch (Exception exception)
                {
                    Assert.IsNotNull(exception);
                    Assert.IsInstanceOfType(exception, typeof(MqttCommunicationException));
                }
                await LongTestDelay(); // disconnected handler is called async
                Assert.IsTrue(disconnectHandlerCalled);
            }
            catch (Exception exception)
            {
                Assert.IsNotNull(exception);
                Assert.IsInstanceOfType(exception, typeof(MqttCommunicationException));
            }
            await LongTestDelay(); // disconnected handler is called async
            Assert.IsTrue(disconnectHandlerCalled);
        }
        [TestMethod]
        public async Task Disconnect_Clean()
        {
-            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
+            using var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500);
            var server = await testEnvironment.StartServer();
            ClientDisconnectedEventArgs eventArgs = null;
            server.ClientDisconnectedAsync += args =>
            {
-                var server = await testEnvironment.StartServer();
+                eventArgs = args;
                return CompletedTask.Instance;
            };
-                ClientDisconnectedEventArgs eventArgs = null;
+            var client = await testEnvironment.ConnectClient();
                server.ClientDisconnectedAsync += args =>
                {
                    eventArgs = args;
                    return CompletedTask.Instance;
                };
-                var client = await testEnvironment.ConnectClient();
+            var disconnectOptions = testEnvironment.ClientFactory.CreateClientDisconnectOptionsBuilder().WithReason(MqttClientDisconnectOptionsReason.MessageRateTooHigh).Build();
-                var disconnectOptions = testEnvironment.ClientFactory.CreateClientDisconnectOptionsBuilder().WithReason(MqttClientDisconnectOptionsReason.MessageRateTooHigh).Build();
+            // Perform a clean disconnect.
            await client.DisconnectAsync(disconnectOptions);
-                // Perform a clean disconnect.
+            await LongTestDelay();
                await client.DisconnectAsync(disconnectOptions);
-                await LongTestDelay();
+            Assert.IsNotNull(eventArgs);
-
+            Assert.AreEqual(MqttClientDisconnectType.Clean, eventArgs.DisconnectType);
                Assert.IsNotNull(eventArgs);
                Assert.AreEqual(MqttClientDisconnectType.Clean, eventArgs.DisconnectType);
            }
        }
        [TestMethod]
        public async Task Disconnect_Clean_With_Custom_Reason()
        {
-            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
+            using var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500);
            var server = await testEnvironment.StartServer();
            ClientDisconnectedEventArgs eventArgs = null;
            server.ClientDisconnectedAsync += args =>
            {
-                var server = await testEnvironment.StartServer();
+                eventArgs = args;
                return CompletedTask.Instance;
            };
-                ClientDisconnectedEventArgs eventArgs = null;
+            var client = await testEnvironment.ConnectClient();
                server.ClientDisconnectedAsync += args =>
                {
                    eventArgs = args;
                    return CompletedTask.Instance;
                };
-                var client = await testEnvironment.ConnectClient();
+            var disconnectOptions = testEnvironment.ClientFactory.CreateClientDisconnectOptionsBuilder().WithReason(MqttClientDisconnectOptionsReason.MessageRateTooHigh).Build();
-                var disconnectOptions = testEnvironment.ClientFactory.CreateClientDisconnectOptionsBuilder().WithReason(MqttClientDisconnectOptionsReason.MessageRateTooHigh).Build();
+            // Perform a clean disconnect.
            await client.DisconnectAsync(disconnectOptions);
-                // Perform a clean disconnect.
+            await LongTestDelay();
                await client.DisconnectAsync(disconnectOptions);
-                await LongTestDelay();
+            Assert.IsNotNull(eventArgs);
-
+            Assert.AreEqual(MqttDisconnectReasonCode.MessageRateTooHigh, eventArgs.ReasonCode);
                Assert.IsNotNull(eventArgs);
                Assert.AreEqual(MqttDisconnectReasonCode.MessageRateTooHigh, eventArgs.ReasonCode);
            }
        }
        [TestMethod]
        public async Task Disconnect_Clean_With_User_Properties()
        {
-            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
+            using var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500);
-            {
+            var server = await testEnvironment.StartServer();
                var server = await testEnvironment.StartServer();
-                ClientDisconnectedEventArgs eventArgs = null;
+            ClientDisconnectedEventArgs eventArgs = null;
-                server.ClientDisconnectedAsync += args =>
+            server.ClientDisconnectedAsync += args =>
            {
                eventArgs = args;
                return CompletedTask.Instance;
            };
            var client = await testEnvironment.ConnectClient();
            var disconnectOptions = testEnvironment.ClientFactory.CreateClientDisconnectOptionsBuilder().WithUserProperty("test_name", "test_value").Build();
            // Perform a clean disconnect.
            await client.DisconnectAsync(disconnectOptions);
            await LongTestDelay();
            Assert.IsNotNull(eventArgs);
            Assert.IsNotNull(eventArgs.UserProperties);
            Assert.AreEqual(1, eventArgs.UserProperties.Count);
            Assert.AreEqual("test_name", eventArgs.UserProperties[0].Name);
            Assert.AreEqual("test_value", eventArgs.UserProperties[0].Value);
        }
        class TestClientKerberosAuthenticationHandler : IMqttEnhancedAuthenticationHandler
        {
            public async Task HandleEnhancedAuthenticationAsync(MqttEnhancedAuthenticationEventArgs eventArgs)
            {
                if (eventArgs.AuthenticationMethod != "GS2-KRB5")
                {
-                    eventArgs = args;
+                    throw new InvalidOperationException("Wrong authentication method");
-                    return CompletedTask.Instance;
+                }
                var sendOptions = new SendMqttEnhancedAuthenticationDataOptions
                {
                    Data = "initial context token"u8.ToArray()
                };
-                var client = await testEnvironment.ConnectClient();
+                await eventArgs.SendAsync(sendOptions, eventArgs.CancellationToken);
-                var disconnectOptions = testEnvironment.ClientFactory.CreateClientDisconnectOptionsBuilder().WithUserProperty("test_name", "test_value").Build();
+                var response = await eventArgs.ReceiveAsync(eventArgs.CancellationToken);
-                // Perform a clean disconnect.
+                Assert.AreEqual(Encoding.UTF8.GetString(response.AuthenticationData), "reply context token");
                await client.DisconnectAsync(disconnectOptions);
-                await LongTestDelay();
+                // No further data is required, but we have to fulfil the exchange.
                sendOptions = new SendMqttEnhancedAuthenticationDataOptions
                {
                    Data = []
                };
-                Assert.IsNotNull(eventArgs);
+                await eventArgs.SendAsync(sendOptions, eventArgs.CancellationToken);
                Assert.IsNotNull(eventArgs.UserProperties);
                Assert.AreEqual(1, eventArgs.UserProperties.Count);
                Assert.AreEqual("test_name", eventArgs.UserProperties[0].Name);
                Assert.AreEqual("test_value", eventArgs.UserProperties[0].Value);
            }
        }
        [TestMethod]
        public async Task Use_Enhanced_Authentication()
        {
            using var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500);
            var server = await testEnvironment.StartServer();
            server.ValidatingConnectionAsync += async args =>
            {
                if (args.AuthenticationMethod == "GS2-KRB5")
                {
                    var result = await args.ExchangeEnhancedAuthenticationAsync(new ExchangeEnhancedAuthenticationOptions(), args.CancellationToken);
                    Assert.AreEqual(Encoding.UTF8.GetString(result.AuthenticationData), "initial context token");
                    var authOptions = testEnvironment.ServerFactory.CreateExchangeExtendedAuthenticationOptionsBuilder().WithAuthenticationData("reply context token").Build();
                    result =  await args.ExchangeEnhancedAuthenticationAsync(authOptions, args.CancellationToken);
                    Assert.AreEqual(Encoding.UTF8.GetString(result.AuthenticationData), "");
                    args.ResponseAuthenticationData = "outcome of authentication"u8.ToArray();
                }
                else
                {
                    args.ReasonCode = MqttConnectReasonCode.BadAuthenticationMethod;
                }
            };
            // Use Kerberos sample from the MQTT RFC.
            var kerberosAuthenticationHandler = new TestClientKerberosAuthenticationHandler();
            var clientOptions = testEnvironment.CreateDefaultClientOptionsBuilder().WithEnhancedAuthentication("GS2-KRB5").WithEnhancedAuthenticationHandler(kerberosAuthenticationHandler);
            var client = await testEnvironment.ConnectClient(clientOptions);
            Assert.IsTrue(client.IsConnected);
        }
        [TestMethod]
        public async Task No_Unobserved_Exception()
        {
-            using (var testEnvironment = CreateTestEnvironment())
+            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
            {
-                testEnvironment.IgnoreClientLogErrors = true;
+                using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(0.5));
-
+                await client.ConnectAsync(options, timeout.Token);
                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();
            }
            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()
        {
-            using (var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500))
+            using var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500);
            var server = await testEnvironment.StartServer();
            server.ValidatingConnectionAsync += args =>
            {
-                var server = await testEnvironment.StartServer();
+                args.ResponseUserProperties = [new("Property", "Value")];
-                server.ValidatingConnectionAsync += args =>
+                args.ReasonCode = MqttConnectReasonCode.QuotaExceeded;
                {
                    args.ResponseUserProperties = new List<MqttUserProperty>
                    {
                        new MqttUserProperty("Property", "Value")
                    };
-                    args.ReasonCode = MqttConnectReasonCode.QuotaExceeded;
+                return CompletedTask.Instance;
            };
-                    return CompletedTask.Instance;
+            var client = testEnvironment.CreateClient();
                };
-                var client = testEnvironment.CreateClient();
+            var response = await client.ConnectAsync(testEnvironment.CreateDefaultClientOptionsBuilder().Build());
-                var response = await client.ConnectAsync(testEnvironment.CreateDefaultClientOptionsBuilder().Build());
+            Assert.IsNotNull(response);
-
+            Assert.AreEqual(MqttClientConnectResultCode.QuotaExceeded, response.ResultCode);
-                Assert.IsNotNull(response);
+            Assert.AreEqual(response.UserProperties[0].Name, "Property");
-                Assert.AreEqual(MqttClientConnectResultCode.QuotaExceeded, response.ResultCode);
+            Assert.AreEqual(response.UserProperties[0].Value, "Value");
                Assert.AreEqual(response.UserProperties[0].Name, "Property");
                Assert.AreEqual(response.UserProperties[0].Value, "Value");
            }
        }
        [TestMethod]
@@ -234,10 +280,8 @@ namespace MQTTnet.Tests.Clients.MqttClient
            try
            {
                var mqttFactory = new MqttClientFactory();
-                using (var mqttClient = mqttFactory.CreateMqttClient())
+                using var mqttClient = mqttFactory.CreateMqttClient();
-                {
+                await mqttClient.SubscribeAsync("test", MqttQualityOfServiceLevel.AtLeastOnce);
                    await mqttClient.SubscribeAsync("test", MqttQualityOfServiceLevel.AtLeastOnce);
                }
            }
            catch (MqttClientNotConnectedException exception)
            {
@@ -27,7 +27,7 @@ namespace MQTTnet.Tests.Clients.MqttClient
    [TestClass]
    public sealed class MqttClient_Tests : BaseTestClass
    {
-        [DataTestMethod]
+        [TestMethod]
        [DataRow(MqttQualityOfServiceLevel.ExactlyOnce)]
        [DataRow(MqttQualityOfServiceLevel.AtMostOnce)]
        [DataRow(MqttQualityOfServiceLevel.AtLeastOnce)]
@@ -11,10 +11,7 @@ namespace MQTTnet.Tests.Helpers
    {
        public static TestApplicationMessageReceivedHandler TrackReceivedMessages(this IMqttClient client)
        {
-            if (client == null)
+            ArgumentNullException.ThrowIfNull(client);
            {
                throw new ArgumentNullException(nameof(client));
            }
            return new TestApplicationMessageReceivedHandler(client);
        }
@@ -11,10 +11,7 @@ namespace MQTTnet.Tests.Helpers
    {
        public static object GetFieldValue(this object source, string fieldName)
        {
-            if (source == null)
+            ArgumentNullException.ThrowIfNull(source);
            {
                throw new ArgumentNullException(nameof(source));
            }
            var field = source.GetType().GetField(fieldName, BindingFlags.Instance | BindingFlags.NonPublic);
            if (field == null)
@@ -16,9 +16,10 @@
    <ItemGroup>
        <PackageReference Include="Microsoft.IO.RecyclableMemoryStream" Version="3.0.1" />
-        <PackageReference Include="MSTest.TestAdapter" Version="3.3.1" />
+        <PackageReference Include="MSTest.TestAdapter" Version="3.6.3" />
-        <PackageReference Include="MSTest.TestFramework" Version="3.3.1" />
+        <PackageReference Include="MSTest.TestFramework" Version="3.6.3" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
        <FrameworkReference Include="Microsoft.AspNetCore.App" />
    </ItemGroup>
@@ -2,10 +2,12 @@
 // 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.AspNetCore.Http;
 using MQTTnet.Channel;
 using MQTTnet.Internal;
 using System.Buffers;
 using System.IO;
 using System.Net;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
@@ -26,7 +28,7 @@ namespace MQTTnet.Tests.Mockups
            _stream = new MemoryStream(buffer);
        }
-        public string Endpoint { get; } = "<Test channel>";
+        public EndPoint RemoteEndPoint { get; set; }
        public bool IsSecureConnection { get; } = false;
@@ -18,10 +18,7 @@ namespace MQTTnet.Tests.Mockups
        public TestApplicationMessageReceivedHandler(IMqttClient mqttClient)
        {
-            if (mqttClient == null)
+            ArgumentNullException.ThrowIfNull(mqttClient);
            {
                throw new ArgumentNullException(nameof(mqttClient));
            }
            mqttClient.ApplicationMessageReceivedAsync += OnApplicationMessageReceivedAsync;
        }
@@ -102,10 +102,7 @@ namespace MQTTnet.Tests.Mockups
        public async Task<IMqttClient> ConnectClient(Action<MqttClientOptionsBuilder> configureOptions, TimeSpan timeout = default)
        {
-            if (configureOptions == null)
+            ArgumentNullException.ThrowIfNull(configureOptions);
            {
                throw new ArgumentNullException(nameof(configureOptions));
            }
            // Start with initial default values.
            var optionsBuilder = ClientFactory.CreateClientOptionsBuilder().WithProtocolVersion(_protocolVersion).WithTcpServer("127.0.0.1", ServerPort);
@@ -134,10 +131,7 @@ namespace MQTTnet.Tests.Mockups
        public async Task<IMqttClient> ConnectClient(MqttClientOptionsBuilder options, TimeSpan timeout = default)
        {
-            if (options == null)
+            ArgumentNullException.ThrowIfNull(options);
            {
                throw new ArgumentNullException(nameof(options));
            }
            options = options.WithTcpServer("127.0.0.1", ServerPort);
@@ -160,10 +154,7 @@ namespace MQTTnet.Tests.Mockups
        public async Task<IMqttClient> ConnectClient(MqttClientOptions options, TimeSpan timeout = default)
        {
-            if (options == null)
+            ArgumentNullException.ThrowIfNull(options);
            {
                throw new ArgumentNullException(nameof(options));
            }
            var client = CreateClient();
@@ -40,10 +40,11 @@ public class MqttTcpChannel_Tests
                },
                ct.Token);
            var remoteEndPoint = new DnsEndPoint("localhost", 50001);
            using var clientSocket = new CrossPlatformSocket(AddressFamily.InterNetwork, ProtocolType.Tcp);
-            await clientSocket.ConnectAsync(new DnsEndPoint("localhost", 50001), CancellationToken.None);
+            await clientSocket.ConnectAsync(remoteEndPoint, CancellationToken.None);
-            var tcpChannel = new MqttTcpChannel(clientSocket.GetStream(), "test", null);
+            var tcpChannel = new MqttTcpChannel(clientSocket.GetStream(), remoteEndPoint, null);
            await Task.Delay(100, ct.Token);
@@ -29,16 +29,17 @@ namespace MQTTnet.Tests.Server
                    return CompletedTask.Instance;
                };
-                await testEnvironment.ConnectClient(o => o.WithCredentials("TheUser"));
+                await testEnvironment.ConnectClient(o => o.WithCredentials("TheUser", "ThePassword"));
                await LongTestDelay();
                Assert.IsNotNull(eventArgs);
                Assert.IsTrue(eventArgs.ClientId.StartsWith(nameof(Fire_Client_Connected_Event)));
-                Assert.IsTrue(eventArgs.Endpoint.Contains("127.0.0.1"));
+                Assert.IsTrue(eventArgs.RemoteEndPoint.ToString().Contains("127.0.0.1"));
                Assert.AreEqual(MqttProtocolVersion.V311, eventArgs.ProtocolVersion);
                Assert.AreEqual("TheUser", eventArgs.UserName);
                Assert.AreEqual("ThePassword", eventArgs.Password);
            }
        }
@@ -56,7 +57,7 @@ namespace MQTTnet.Tests.Server
                    return CompletedTask.Instance;
                };
-                var client = await testEnvironment.ConnectClient(o => o.WithCredentials("TheUser"));
+                var client = await testEnvironment.ConnectClient(o => o.WithCredentials("TheUser", "ThePassword"));
                await client.DisconnectAsync();
                await LongTestDelay();
@@ -64,8 +65,11 @@ namespace MQTTnet.Tests.Server
                Assert.IsNotNull(eventArgs);
                Assert.IsTrue(eventArgs.ClientId.StartsWith(nameof(Fire_Client_Disconnected_Event)));
-                Assert.IsTrue(eventArgs.Endpoint.Contains("127.0.0.1"));
+                Assert.IsTrue(eventArgs.RemoteEndPoint.ToString().Contains("127.0.0.1"));
                Assert.AreEqual(MqttClientDisconnectType.Clean, eventArgs.DisconnectType);
                Assert.AreEqual("TheUser", eventArgs.UserName);
                Assert.AreEqual("ThePassword", eventArgs.Password);
            }
        }
@@ -83,7 +87,7 @@ namespace MQTTnet.Tests.Server
                    return CompletedTask.Instance;
                };
-                var client = await testEnvironment.ConnectClient();
+                var client = await testEnvironment.ConnectClient(o => o.WithCredentials("TheUser"));
                await client.SubscribeAsync("The/Topic", MqttQualityOfServiceLevel.AtLeastOnce);
                await LongTestDelay();
@@ -93,6 +97,7 @@ namespace MQTTnet.Tests.Server
                Assert.IsTrue(eventArgs.ClientId.StartsWith(nameof(Fire_Client_Subscribed_Event)));
                Assert.AreEqual("The/Topic", eventArgs.TopicFilter.Topic);
                Assert.AreEqual(MqttQualityOfServiceLevel.AtLeastOnce, eventArgs.TopicFilter.QualityOfServiceLevel);
                Assert.AreEqual("TheUser", eventArgs.UserName);
            }
        }
@@ -110,7 +115,7 @@ namespace MQTTnet.Tests.Server
                    return CompletedTask.Instance;
                };
-                var client = await testEnvironment.ConnectClient();
+                var client = await testEnvironment.ConnectClient(o => o.WithCredentials("TheUser"));
                await client.UnsubscribeAsync("The/Topic");
                await LongTestDelay();
@@ -119,6 +124,7 @@ namespace MQTTnet.Tests.Server
                Assert.IsTrue(eventArgs.ClientId.StartsWith(nameof(Fire_Client_Unsubscribed_Event)));
                Assert.AreEqual("The/Topic", eventArgs.TopicFilter);
                Assert.AreEqual("TheUser", eventArgs.UserName);
            }
        }
@@ -136,7 +142,7 @@ namespace MQTTnet.Tests.Server
                    return CompletedTask.Instance;
                };
-                var client = await testEnvironment.ConnectClient();
+                var client = await testEnvironment.ConnectClient(o => o.WithCredentials("TheUser"));
                await client.PublishStringAsync("The_Topic", "The_Payload");
                await LongTestDelay();
@@ -146,6 +152,7 @@ namespace MQTTnet.Tests.Server
                Assert.IsTrue(eventArgs.ClientId.StartsWith(nameof(Fire_Application_Message_Received_Event)));
                Assert.AreEqual("The_Topic", eventArgs.ApplicationMessage.Topic);
                Assert.AreEqual("The_Payload", eventArgs.ApplicationMessage.ConvertPayloadToString());
                Assert.AreEqual("TheUser", eventArgs.UserName);
            }
        }
@@ -182,7 +182,7 @@ namespace MQTTnet.Tests.Server
            }
        }
-        [DataTestMethod]
+        [TestMethod]
        [DataRow(MqttQualityOfServiceLevel.ExactlyOnce)]
        [DataRow(MqttQualityOfServiceLevel.AtLeastOnce)]
        public async Task Retry_If_Not_PubAck(MqttQualityOfServiceLevel qos)
@@ -20,7 +20,7 @@ namespace MQTTnet.Tests.Server
    [TestClass]
    public sealed class Subscribe_Tests : BaseTestClass
    {
-        [DataTestMethod]
+        [TestMethod]
        [DataRow("A", "A", true)]
        [DataRow("A", "B", false)]
        [DataRow("A", "#", true)]
@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 using System;
 using System.Net;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
@@ -18,7 +19,8 @@ public interface IMqttChannelAdapter : IDisposable
    long BytesSent { get; }
    X509Certificate2 ClientCertificate { get; }
-    string Endpoint { get; }
+
    EndPoint RemoteEndPoint { get; }
    bool IsSecureConnection { get; }
@@ -5,6 +5,7 @@
 using System;
 using System.Buffers;
 using System.IO;
 using System.Net;
 using System.Net.Sockets;
 using System.Runtime.InteropServices;
 using System.Security.Cryptography.X509Certificates;
@@ -38,10 +39,7 @@ public sealed class MqttChannelAdapter : Disposable, IMqttChannelAdapter
        PacketFormatterAdapter = packetFormatterAdapter ?? throw new ArgumentNullException(nameof(packetFormatterAdapter));
-        if (logger == null)
+        ArgumentNullException.ThrowIfNull(logger);
        {
            throw new ArgumentNullException(nameof(logger));
        }
        _logger = logger.WithSource(nameof(MqttChannelAdapter));
    }
@@ -54,7 +52,7 @@ public sealed class MqttChannelAdapter : Disposable, IMqttChannelAdapter
    public X509Certificate2 ClientCertificate => _channel.ClientCertificate;
-    public string Endpoint => _channel.Endpoint;
+    public EndPoint RemoteEndPoint => _channel.RemoteEndPoint;
    public bool IsSecureConnection => _channel.IsSecureConnection;
@@ -23,10 +23,7 @@ public sealed class MqttPacketInspector
    {
        _asyncEvent = asyncEvent ?? throw new ArgumentNullException(nameof(asyncEvent));
-        if (logger == null)
+        ArgumentNullException.ThrowIfNull(logger);
        {
            throw new ArgumentNullException(nameof(logger));
        }
        _logger = logger.WithSource(nameof(MqttPacketInspector));
    }
@@ -4,6 +4,7 @@
 using System;
 using System.Buffers;
 using System.Net;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading;
 using System.Threading.Tasks;
@@ -13,7 +14,7 @@ namespace MQTTnet.Channel;
 public interface IMqttChannel : IDisposable
 {
    X509Certificate2 ClientCertificate { get; }
-    string Endpoint { get; }
+    EndPoint RemoteEndPoint { get; }
    bool IsSecureConnection { get; }
@@ -14,10 +14,7 @@ public sealed class MqttClientConnectResultFactory
 {
    public MqttClientConnectResult Create(MqttConnAckPacket connAckPacket, MqttProtocolVersion protocolVersion)
    {
-        if (connAckPacket == null)
+        ArgumentNullException.ThrowIfNull(connAckPacket);
        {
            throw new ArgumentNullException(nameof(connAckPacket));
        }
        if (protocolVersion == MqttProtocolVersion.V500)
        {
@@ -68,10 +65,8 @@ public sealed class MqttClientConnectResultFactory
    static MqttClientConnectResult CreateForMqtt311(MqttConnAckPacket connAckPacket)
    {
-        if (connAckPacket == null)
+        ArgumentNullException.ThrowIfNull(connAckPacket);
-        {
+
            throw new ArgumentNullException(nameof(connAckPacket));
        }
        return new MqttClientConnectResult
        {
@@ -84,10 +79,7 @@ public sealed class MqttClientConnectResultFactory
    static MqttClientConnectResult CreateForMqtt500(MqttConnAckPacket connAckPacket)
    {
-        if (connAckPacket == null)
+        ArgumentNullException.ThrowIfNull(connAckPacket);
        {
            throw new ArgumentNullException(nameof(connAckPacket));
        }
        return new MqttClientConnectResult
        {
@@ -209,10 +209,7 @@ namespace MQTTnet.Diagnostics.Logger
        public static MqttNetSourceLogger WithSource(this IMqttNetLogger logger, string source)
        {
-            if (logger == null)
+            ArgumentNullException.ThrowIfNull(logger);
            {
                throw new ArgumentNullException(nameof(logger));
            }
            return new MqttNetSourceLogger(logger, source);
        }
@@ -12,10 +12,7 @@ public static class MqttClientDisconnectOptionsValidator
 {
    public static void ThrowIfNotSupported(MqttClientDisconnectOptions options, MqttProtocolVersion protocolVersion)
    {
-        if (options == null)
+        ArgumentNullException.ThrowIfNull(options);
        {
            throw new ArgumentNullException(nameof(options));
        }
        if (protocolVersion == MqttProtocolVersion.V500)
        {
@@ -1,66 +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.Packets;
 using MQTTnet.Protocol;
 namespace MQTTnet;
 public class MqttExtendedAuthenticationExchangeContext
 {
    public MqttExtendedAuthenticationExchangeContext(MqttAuthPacket authPacket, MqttClient client)
    {
        if (authPacket == null)
        {
            throw new ArgumentNullException(nameof(authPacket));
        }
        ReasonCode = authPacket.ReasonCode;
        ReasonString = authPacket.ReasonString;
        AuthenticationMethod = authPacket.AuthenticationMethod;
        AuthenticationData = authPacket.AuthenticationData;
        UserProperties = authPacket.UserProperties;
        Client = client ?? throw new ArgumentNullException(nameof(client));
    }
    /// <summary>
    ///     Gets the authentication data.
    ///     Hint: MQTT 5 feature only.
    /// </summary>
    public byte[] AuthenticationData { get; }
    /// <summary>
    ///     Gets the authentication method.
    ///     Hint: MQTT 5 feature only.
    /// </summary>
    public string AuthenticationMethod { get; }
    public MqttClient Client { get; }
    /// <summary>
    ///     Gets the reason code.
    ///     Hint: MQTT 5 feature only.
    /// </summary>
    public MqttAuthenticateReasonCode ReasonCode { get; }
    /// <summary>
    ///     Gets the reason string.
    ///     Hint: MQTT 5 feature only.
    /// </summary>
    public string ReasonString { get; }
    /// <summary>
    ///     Gets the user properties.
    ///     In MQTT 5, user properties are basic UTF-8 string key-value pairs that you can append to almost every type of MQTT
    ///     packet.
    ///     As long as you don’t exceed the maximum message size, you can use an unlimited number of user properties to add
    ///     metadata to MQTT messages and pass information between publisher, broker, and subscriber.
    ///     The feature is very similar to the HTTP header concept.
    ///     Hint: MQTT 5 feature only.
    /// </summary>
    public List<MqttUserProperty> UserProperties { get; }
 }
@@ -11,10 +11,7 @@ namespace MQTTnet.Formatter
    {
        public static MqttApplicationMessage Create(MqttPublishPacket publishPacket)
        {
-            if (publishPacket == null)
+            ArgumentNullException.ThrowIfNull(publishPacket);
            {
                throw new ArgumentNullException(nameof(publishPacket));
            }
            return new MqttApplicationMessage
            {
@@ -105,10 +105,7 @@ namespace MQTTnet.Formatter
        public void Write(MqttBufferWriter propertyWriter)
        {
-            if (propertyWriter == null)
+            ArgumentNullException.ThrowIfNull(propertyWriter);
            {
                throw new ArgumentNullException(nameof(propertyWriter));
            }
            WriteBinary(propertyWriter._buffer, 0, propertyWriter.Length);
        }
@@ -140,10 +137,7 @@ namespace MQTTnet.Formatter
        public void WriteBinary(byte[] buffer, int offset, int count)
        {
-            if (buffer == null)
+            ArgumentNullException.ThrowIfNull(buffer);
            {
                throw new ArgumentNullException(nameof(buffer));
            }
            if (count == 0)
            {
@@ -11,10 +11,7 @@ public static class MqttConnectPacketFactory
 {
    public static MqttConnectPacket Create(MqttClientOptions clientOptions)
    {
-        if (clientOptions == null)
+        ArgumentNullException.ThrowIfNull(clientOptions);
        {
            throw new ArgumentNullException(nameof(clientOptions));
        }
        var connectPacket = new MqttConnectPacket
        {
@@ -12,10 +12,7 @@ public static class MqttPubAckPacketFactory
 {
    public static MqttPubAckPacket Create(MqttApplicationMessageReceivedEventArgs applicationMessageReceivedEventArgs)
    {
-        if (applicationMessageReceivedEventArgs == null)
+        ArgumentNullException.ThrowIfNull(applicationMessageReceivedEventArgs);
        {
            throw new ArgumentNullException(nameof(applicationMessageReceivedEventArgs));
        }
        var pubAckPacket = new MqttPubAckPacket
        {
@@ -12,10 +12,7 @@ public static class MqttPubCompPacketFactory
 {
    public static MqttPubCompPacket Create(MqttPubRelPacket pubRelPacket, MqttApplicationMessageReceivedReasonCode reasonCode)
    {
-        if (pubRelPacket == null)
+        ArgumentNullException.ThrowIfNull(pubRelPacket);
        {
            throw new ArgumentNullException(nameof(pubRelPacket));
        }
        return new MqttPubCompPacket
        {
@@ -12,10 +12,7 @@ public static class MqttPubRecPacketFactory
 {
    public static MqttPubRecPacket Create(MqttApplicationMessageReceivedEventArgs applicationMessageReceivedEventArgs)
    {
-        if (applicationMessageReceivedEventArgs == null)
+        ArgumentNullException.ThrowIfNull(applicationMessageReceivedEventArgs);
        {
            throw new ArgumentNullException(nameof(applicationMessageReceivedEventArgs));
        }
        var pubRecPacket = Create(applicationMessageReceivedEventArgs.PublishPacket, applicationMessageReceivedEventArgs.ReasonCode);
        pubRecPacket.UserProperties = applicationMessageReceivedEventArgs.ResponseUserProperties;
@@ -12,10 +12,7 @@ public static class MqttPubRelPacketFactory
 {
    public static MqttPubRelPacket Create(MqttPubRecPacket pubRecPacket, MqttApplicationMessageReceivedReasonCode reasonCode)
    {
-        if (pubRecPacket == null)
+        ArgumentNullException.ThrowIfNull(pubRecPacket);
        {
            throw new ArgumentNullException(nameof(pubRecPacket));
        }
        return new MqttPubRelPacket
        {
@@ -12,10 +12,7 @@ namespace MQTTnet.Formatter
    {
        public static MqttPublishPacket Create(MqttApplicationMessage applicationMessage)
        {
-            if (applicationMessage == null)
+            ArgumentNullException.ThrowIfNull(applicationMessage);
            {
                throw new ArgumentNullException(nameof(applicationMessage));
            }
            // Copy all values to their matching counterparts.
            // The not supported values in MQTT 3.1.1 are not serialized (excluded) later.
@@ -11,10 +11,7 @@ public static class MqttSubscribePacketFactory
 {
    public static MqttSubscribePacket Create(MqttClientSubscribeOptions clientSubscribeOptions)
    {
-        if (clientSubscribeOptions == null)
+        ArgumentNullException.ThrowIfNull(clientSubscribeOptions);
        {
            throw new ArgumentNullException(nameof(clientSubscribeOptions));
        }
        var packet = new MqttSubscribePacket
        {
@@ -11,10 +11,7 @@ public static class MqttUnsubscribePacketFactory
 {
    public static MqttUnsubscribePacket Create(MqttClientUnsubscribeOptions clientUnsubscribeOptions)
    {
-        if (clientUnsubscribeOptions == null)
+        ArgumentNullException.ThrowIfNull(clientUnsubscribeOptions);
        {
            throw new ArgumentNullException(nameof(clientUnsubscribeOptions));
        }
        var packet = new MqttUnsubscribePacket
        {
@@ -2,24 +2,23 @@
 // 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.Formatter
+namespace MQTTnet.Formatter;
 public struct ReadFixedHeaderResult
 {
-    public struct ReadFixedHeaderResult
+    public static ReadFixedHeaderResult Canceled { get; } = new()
    {
-        public static ReadFixedHeaderResult Canceled { get; } = new ReadFixedHeaderResult
+        IsCanceled = true
-        {
+    };
            IsCanceled = true
        };
-        public static ReadFixedHeaderResult ConnectionClosed { get; } = new ReadFixedHeaderResult
+    public static ReadFixedHeaderResult ConnectionClosed { get; } = new()
-        {
+    {
-            IsConnectionClosed = true
+        IsConnectionClosed = true
-        };
+    };
-        public bool IsCanceled { get; set; }
+    public bool IsCanceled { get; set; }
-        public bool IsConnectionClosed { get; set; }
+    public bool IsConnectionClosed { get; init; }
-        public MqttFixedHeader FixedHeader { get; set; }
+    public MqttFixedHeader FixedHeader { get; init; }
    }
 }
@@ -18,9 +18,9 @@ namespace MQTTnet.Formatter.V3
    {
        const int FixedHeaderSize = 1;
-        static readonly MqttDisconnectPacket DisconnectPacket = new MqttDisconnectPacket();
+        static readonly MqttDisconnectPacket DisconnectPacket = new();
-        readonly MqttBufferReader _bufferReader = new MqttBufferReader();
+        readonly MqttBufferReader _bufferReader = new();
        readonly MqttBufferWriter _bufferWriter;
        readonly MqttProtocolVersion _mqttProtocolVersion;
@@ -68,10 +68,8 @@ namespace MQTTnet.Formatter.V3
                    {
                        return DecodeConnAckPacketV311(receivedMqttPacket.Body);
                    }
-                    else
+
-                    {
+                    return DecodeConnAckPacket(receivedMqttPacket.Body);
                        return DecodeConnAckPacket(receivedMqttPacket.Body);
                    }
                case MqttControlPacketType.Disconnect:
                    return DisconnectPacket;
@@ -91,10 +89,7 @@ namespace MQTTnet.Formatter.V3
        public MqttPacketBuffer Encode(MqttPacket packet)
        {
-            if (packet == null)
+            ArgumentNullException.ThrowIfNull(packet);
            {
                throw new ArgumentNullException(nameof(packet));
            }
            // Leave enough head space for max header size (fixed + 4 variable remaining length = 5 bytes)
            _bufferWriter.Reset(5);
@@ -109,10 +104,6 @@ namespace MQTTnet.Formatter.V3
                payload = publishPacket.Payload;
                remainingLength += (uint)payload.Length;
            }
            else
            {
                publishPacket = null;
            }
            var remainingLengthSize = MqttBufferWriter.GetVariableByteIntegerSize(remainingLength);
@@ -484,7 +475,16 @@ namespace MQTTnet.Formatter.V3
            ValidateConnectPacket(packet);
            bufferWriter.WriteString("MQTT");
-            bufferWriter.WriteByte(4); // 3.1.2.2 Protocol Level 4
+
            // 3.1.2.2 Protocol Level 4
            var protocolVersion = 4;
            if (packet.TryPrivate)
            {
                protocolVersion |= 0x80;
            }
            bufferWriter.WriteByte((byte)protocolVersion);
            byte connectFlags = 0x0;
            if (packet.CleanSession)
@@ -555,19 +555,15 @@ namespace MQTTnet.Formatter.V3
                    {
                        return EncodeConnectPacketV311(connectPacket, bufferWriter);
                    }
-                    else
+
-                    {
+                    return EncodeConnectPacket(connectPacket, bufferWriter);
                        return EncodeConnectPacket(connectPacket, bufferWriter);
                    }
                case MqttConnAckPacket connAckPacket:
                    if (_mqttProtocolVersion == MqttProtocolVersion.V311)
                    {
                        return EncodeConnAckPacketV311(connAckPacket, bufferWriter);
                    }
-                    else
+
-                    {
+                    return EncodeConnAckPacket(connAckPacket, bufferWriter);
                        return EncodeConnAckPacket(connAckPacket, bufferWriter);
                    }
                case MqttDisconnectPacket _:
                    return EncodeEmptyPacket(MqttControlPacketType.Disconnect);
                case MqttPingReqPacket _:
@@ -797,10 +793,7 @@ namespace MQTTnet.Formatter.V3
        void ValidateConnectPacket(MqttConnectPacket packet)
        {
-            if (packet == null)
+            ArgumentNullException.ThrowIfNull(packet);
            {
                throw new ArgumentNullException(nameof(packet));
            }
            if (string.IsNullOrEmpty(packet.ClientId) && !packet.CleanSession)
            {
@@ -13,7 +13,7 @@ namespace MQTTnet.Formatter.V5
 {
    public sealed class MqttV5PacketDecoder
    {
-        readonly MqttBufferReader _bufferReader = new MqttBufferReader();
+        readonly MqttBufferReader _bufferReader = new();
        public MqttPacket Decode(ReceivedMqttPacket receivedMqttPacket)
        {
@@ -25,10 +25,7 @@ public sealed class MqttV5PacketEncoder
    public MqttPacketBuffer Encode(MqttPacket packet)
    {
-        if (packet == null)
+        ArgumentNullException.ThrowIfNull(packet);
        {
            throw new ArgumentNullException(nameof(packet));
        }
        // Leave enough head space for max header size (fixed + 4 variable remaining length = 5 bytes)
        const int ReservedHeaderSize = 5;
@@ -230,10 +230,7 @@ namespace MQTTnet.Formatter.V5
        public void WriteTo(MqttBufferWriter target)
        {
-            if (target == null)
+            ArgumentNullException.ThrowIfNull(target);
            {
                throw new ArgumentNullException(nameof(target));
            }
            target.WriteVariableByteInteger((uint)_bufferWriter.Length);
            target.Write(_bufferWriter);
@@ -29,7 +29,7 @@ public interface IMqttClient : IDisposable
    Task<MqttClientPublishResult> PublishAsync(MqttApplicationMessage applicationMessage, CancellationToken cancellationToken = default);
-    Task SendExtendedAuthenticationExchangeDataAsync(MqttExtendedAuthenticationExchangeData data, CancellationToken cancellationToken = default);
+    Task SendEnhancedAuthenticationExchangeDataAsync(MqttEnhancedAuthenticationExchangeData data, CancellationToken cancellationToken = default);
    Task<MqttClientSubscribeResult> SubscribeAsync(MqttClientSubscribeOptions options, CancellationToken cancellationToken = default);
@@ -124,20 +124,14 @@ public sealed class CrossPlatformSocket : IDisposable
    public void Bind(EndPoint localEndPoint)
    {
-        if (localEndPoint is null)
+        ArgumentNullException.ThrowIfNull(localEndPoint);
        {
            throw new ArgumentNullException(nameof(localEndPoint));
        }
        _socket.Bind(localEndPoint);
    }
    public async Task ConnectAsync(EndPoint endPoint, CancellationToken cancellationToken)
    {
-        if (endPoint is null)
+        ArgumentNullException.ThrowIfNull(endPoint);
        {
            throw new ArgumentNullException(nameof(endPoint));
        }
        cancellationToken.ThrowIfCancellationRequested();
@@ -14,7 +14,7 @@ namespace MQTTnet.Implementations
    {
        public IMqttChannelAdapter CreateClientAdapter(MqttClientOptions options, MqttPacketInspector packetInspector, IMqttNetLogger logger)
        {
-            if (options == null) throw new ArgumentNullException(nameof(options));
+            ArgumentNullException.ThrowIfNull(options);
            IMqttChannel channel;
            switch (options.ChannelOptions)
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
christian	7715bf37dc	Remove package suffix for final release version	2024-12-30 11:54:00 +01:00
Christian	9dbe1e4b12	Fix support for enhanced authentication (#2132 ) * Implement enhanced authentication for client and server. * Update samples * Add abstraction layer * Merge master * Use dedicated class for public API. * Update release notes * Rename methods to fit naming scheme * Fix unit tests and samples	2024-12-25 14:17:20 +01:00
christian	f13b3eb6bb	Update release notes	2024-12-23 12:17:00 +01:00
Anton SmolkovandAnton Smolkov	8eb884fa5d	Add ability to get session from server by client id (#2131 ) Co-authored-by: Anton Smolkov <anton.smolkov@idp.zyfra.com>	2024-12-23 12:05:09 +01:00
Victornorandchristian	9f81a2bb71	Add deflate compressions options to MqttClientWebSocketOptionsBuilder (#2127 ) * fix: unused tryPrivate parameter in WithTryPrivate * Fix wrong usage of try private * feat: add option to provide deflate compression options to WebSocketOptionsBuilder --------- Co-authored-by: christian <6939810+chkr1011@users.noreply.github.com>	2024-12-23 11:21:46 +01:00
老九andchristian	e2f8d0f0ac	Added UserName property to various Server EventArgs. (#2123 ) * Added UserName property to various Server EventArgs. * InjectedMqttApplicationMessage: Add SenderUserName property. * Reformat code * Reformat code --------- Co-authored-by: christian <6939810+chkr1011@users.noreply.github.com>	2024-12-10 19:44:38 +01:00
Victornorandchristian	981ea02149	Unused parameter in WithTryPrivate causing client to send incorrect version byte in header. (#2125 ) * fix: unused tryPrivate parameter in WithTryPrivate * Fix wrong usage of try private --------- Co-authored-by: christian <6939810+chkr1011@users.noreply.github.com>	2024-12-10 19:37:29 +01:00
Christian	8566fd5395	Replace all _DataTestMethod_ (#2119 ) * Replace all DataTestMethod with TestMethod. * Update test nugets	2024-12-03 11:40:06 +01:00
老九andchristian	8089c6bdbc	Added EndPoint RemoteEndPoint {get;} property to channel (#2111 ) * Added EndPoint RemoteEndPoint{get;} property * Reformat code * Reformat code --------- Co-authored-by: christian <6939810+chkr1011@users.noreply.github.com>	2024-12-02 11:52:24 +01:00
christian	ef5b6c9b32	Merge remote-tracking branch 'origin/master'	2024-12-02 11:22:11 +01:00
christian	4aa4a12e47	Update release notes	2024-12-02 10:40:05 +01:00
老九	6bf2b4eaca	Cannot set any properties of tcpOptions when with WebSocketServer. (#2118 )	2024-12-02 10:24:03 +01:00
老九	6ef6b57064	Improve the compatibility of MqttClientOptionsBuilder.WithConnectionUri() (#2107 ) * Improve the compatibility of MqttClientOptionsBuilder.WithConnectionUri() method. * Force UseTls to true for secure schemes. * Add support for UnixDomainSocket.	2024-12-01 14:10:58 +01:00
老九	7d4027958c	Set the default value of SslProtocol to SslProtocols.None. (#2106 ) * Set the default value of SslProtocol to SslProtocols.None. * Add summary of SslProtocol.	2024-12-01 14:06:19 +01:00
老九	bdb74642c2	MqttClientFactory: Fix CreateLowLevelMqttClient not using method parameters (#2110 ) * Fix CreateLowLevelMqttClient not using method parameters. * Remove UseClientAdapterFactory()	2024-11-30 13:46:36 +01:00
Andrea Vouk	63d85184e1	Convert null checks to modern ThrowIfNull checks (#2089 ) Convert null check to modern ThrowIfNull checks	2024-10-26 11:41:58 +02:00
Christian	0506857f0d	Set max pending mesages per client to 1000 (#2096 ) Set max pending mesages per client to 1000.	2024-10-26 11:41:25 +02:00
christian	6417baa081	Fix nuget publish	2024-10-22 11:08:29 +02:00