v5.0.0-rc1

! Read the migration guide (https://github.com/dotnet/MQTTnet/wiki/Upgrading-guide) before migrating to version 5!

Changes

• Memory usage optimizations (thanks to @mregen)
• Performance optimizations (thanks to @mregen)
• Removal of no longer supported .NET Frameworks (BREAKING CHANGE)
• Changed code signing and nuget certificate
• Namespace changes (BREAKING CHANGE)
• Removal of Managed Client (BREAKING CHANGE)
• Client: MQTT 5.0.0 is now the default version when connecting with a server (BREAKING CHANGE)

v4.3.7.1207

• Core: Fixed issue when parsing AUTH packet with 0 length body (#2039).
• nuget: Changed code signing and nuget certificate (BREAKING CHANGE).
• TopicTemplates: Updated samples, parameter validation (#2022).
• ManagedClient: Switch SubscribeAsync/UnsubscribeAsync to IEnumerable (#2026).
• Server: Fix LoadingRetainedMessageAsync not executed (#2025).

v4.3.6.1152

• [Client] Restored Server and Port behavior of client options (#2005).

v4.3.5.1141

• [Client] Fix None of the discovered or specified addresses match the socket address family. (#1997).
• [Client] Remove the obsolete attribute from the WithConnectionUri methods (#1979).

v4.3.4.1084

• [Core] Optimized packet serialization of PUBACK and PUBREC packets for protocol version 5.0.0 (#1939, thanks to @Y-Sindo).
• [Core] The package inspector is now fully async (#1941).
• [Client] Added a dedicated exception when the client is not connected (#1954, thanks to @marcpiulachs).
• [Client] The client will now throw a MqttClientUnexpectedDisconnectReceivedException when publishing a QoS 0 message which leads to a server disconnect (BREAKING CHANGE!, #1974, thanks to @fazho).
• [Client] Exposed the certificate selection event handler in client options (#1984).
• [Server] The server will no longer send NoMatchingSubscribers when the actual subscription was non success (#1965, BREAKING CHANGE!).
• [Server] Fixed broken support for null in AddServer method in ASP.NET integration (#1981).
• [ManagedClient] Added a new event (SubscriptionsChangedAsync) which is fired when a subscription or unsubscription was made (#1894, thanks to @pdufrene).
• [ManagedClient] Fixed race condition when server shuts down while subscribing (#1987, thanks to @marve).
• [TopicTemplate] Added new extension which provides a template engine for topics (#1932, thanks to @simonthum).

v4.3.3.952

• [Server] Added new events for delivered and dropped messages (#1866, thanks to @kallayj).
• [Server] The server will no longer treat a client which is receiving a large payload as alive. The packet must be received completely within the keep alive boundaries (BREAKING CHANGE!, #1883).
• [Server] Fixed "service not registered" exception in ASP.NET integration (#1889).

v4.3.2.930

• [Client] Added support for custom CA chain validation (#1851, thanks to @rido-min).
• [Client] Fixed handling of unobserved tasks exceptions (#1871).
• [Client] Fixed not specified ReasonCode when using SendExtendedAuthenticationExchangeDataAsync (#1882, thanks to @rido-min).
• [Server] Fixed not working UpdateRetainedMessageAsync public api (#1858, thanks to @kimdiego2098).
• [Server] Added support for custom DISCONNECT packets when stopping the server or disconnect a client (BREAKING CHANGE!, #1846).
• [Server] Added new property to stop the server from accepting new connections even if it is running (#1846).

v4.3.1.873

• [Client] Fixed wrong TLS options handling (#1830).
• [Client] Fixed NullReferenceExeption when performing a Ping when the client is not connected (#1831).

v4.3.0.858

• [Client] Fixed PlatformNotSupportedException when using Blazor (#1755, thanks to @Nickztar).
• [Client] Added hot reload of client certificates (#1781).
• [Client] Added several new option builders and aligned usage (#1781, BREAKING CHANGE!).
• [Client] Added support for RemoteCertificateValidationCallback for .NET 4.5.2, 4.6.1 and 4.8 (#1806, thanks to @troky).
• [Client] Fixed wrong logging of obsolete feature when connection was not successful (#1801, thanks to @ramonsmits).
• [Client] Fixed NullReferenceException when performing several actions when not connected (#1800, thanks to @ramonsmits).
• [RpcClient] Added support for passing custom parameters to topic generation context (#1798, thanks to @Temppus).
• [Server] Fixed NullReferenceException in retained messages management (#1762, thanks to @logicaloud).
• [Server] Exposed new option which allows disabling packet fragmentation (#1753).
• [Server] Expired sessions will no longer be used when a client connects (#1756).
• [Server] Fixed an issue in connection handling for ASP.NET connections (#1819, thanks to @CZEMacLeod).

v4.2.1.781

• [Core] Add validation of maximum string lengths (#1718).
• [Core] Added .NET 4.8 builds (#1729).
• [Core] Exposed more details of DISCONNECT packet in log (#1729).
• [Core] Fixed ArgumentNullException in ConvertPayloadToString (#1745, thanks to @ramonsmits).
• [Client] Added overloads for setting packet payload and will payload (#1720).
• [Client] The proper connect result is now exposed in the Disconnected event when authentication fails (#1139).
• [Client] Exposed UseDefaultCredentials and more for Web Socket options and proxy options (#1734, thanks to @impworks).
• [Client] Exposed more TLS options (#1729).
• [Client] Fixed wrong return code conversion (#1729).
• [Client] Added an option to avoid throwing an exception when the server returned a proper non success (but valid) response (#1681).
• [Server] Improved performance by changing internal locking strategy for subscriptions (#1716, thanks to @zeheng).
• [Server] Fixed exceptions when clients are connecting and disconnecting very fast while accessing the client status for connection validation (#1742).
• [Server] Exposed more properties in ClientConnectedEventArgs (#1738).