# MQTTBroker Control A lightweight, fully-featured MQTT broker implementation. ## Syntax **MQTTBroker** ## Remarks The MQTTBroker control provides a lightweight, fully-featured MQTT broker implementation with support for version 3.1.1. The control supports plaintext and TLS-enabled connections over both standard TCP and WebSockets. ### Configuring Listeners The [AddBrokerListener](#addbrokerlistener-method-mqttbroker-control) method adds a new listener to the Listeners collection. Any listeners must be configured before starting the broker. Multiple protocols can be supported by adding different listeners. The control supports the following protocols: | | | | --- | --- | | 0 (mbpTCP) | Plaintext TCP | | 1 (mbpTLS) | SSL/TLS over TCP | | 2 (mbpWS) | Plaintext WebSocket | | 3 (mbpWSS) | SSL/TLS over WebSocket | Multiple protocols can be enabled (each on a different port): ```csharp // Plaintext TCP mqttbroker.AddBrokerListener("127.0.0.1", PLAIN_PORT, (int)MQTTBrokerProtocols.mbpTCP, 0, null, null, null); // TCP with TLS mqttbroker.AddBrokerListener("127.0.0.1", SSL_PORT, (int)MQTTBrokerProtocols.mbpTLS, (int)CertStoreTypes.cstPFXFile, "test1.pfx", "test", "*"); // Plaintext WebSocket mqttbroker.AddBrokerListener("127.0.0.1", WS_PORT, (int)MQTTBrokerProtocols.mbpWS, 0, null, null, null); // WebSocket with TLS mqttbroker.AddBrokerListener("127.0.0.1", WSS_PORT, (int)MQTTBrokerProtocols.mbpWSS, (int)CertStoreTypes.cstPFXFile, "test2.pfx", "test", "*"); ``` Once all listeners have been added, the broker can be started via the [StartListening](#startlistening-method-mqttbroker-control) method. ### Handling Sessions When an MQTT client requests a session, the [SessionRequest](#sessionrequest-event-mqttbroker-control) event will fire with session details. The *UserName* and *Password* parameters can be checked before setting *Accept* to True to accept the session request. *Accept* can be set to False to reject the session request. ```csharp broker.OnSessionRequest += (s,e) => { // Check e.UserName and e.Password if needed // Set Accept to true to accept the session request e.Accept = true; }; ``` ### Handling Subscriptions When an MQTT client requests to subscribe to a topic, the [Subscribe](#subscribe-event-mqttbroker-control) event will fire. The *ClientId* is used to identify this client in subsequent actions. The *TopicFilter* is the requested topic the client wishes to subscribe to. The *RequestedQoS* is the client's preferred QoS level. *ReturnCode* is used to confirm the maximum QoS level granted for this subscription or indicate a failure. This can be less than the client's *RequestedQoS*. | | | | --- | --- | | 0x00 | Success - Maximum QoS 0 | | 0x01 | Success - Maximum QoS 1 | | 0x02 | Success - Maximum QoS 2 | | 0x80 | Failure | When a client requests to unsubscribe from a topic, the [Unsubscribe](#unsubscribe-event-mqttbroker-control) event will fire, specifying which *TopicFilter* the client is unsubscribing from. ### Incoming Messages The MQTTBroker control will automatically forward received messages to any subscribed clients. Events can be used to record the state of any incoming messages. The [MessageReceiving](#messagereceiving-event-mqttbroker-control) event fires when a message is initially received and contains message metadata. The [IncomingMessageStatus](#incomingmessagestatus-event-mqttbroker-control) event fires each time an incoming message's state is updated. - MessageId: A unique identifier for this message. - DUP: Whether or not the server has indicated that this message is a duplicate of another message received previously. - QoS: The message's QoS level. - Retain: Whether or not this message was received as a result of subscribing to a topic. - PacketId: The message packet Id. This will always be -1 if QoS is 0. - State: Information about the incoming message's state. - 6 - For an incoming QoS 1 message, which has been received from the client, but prior to sending the PUBACK for it. When the PUBACK is sent, the state will change to 10. - 7 - For an incoming QoS 2 message, which has been received from a client, but prior to sending the PUBREC for it, - 8 - For an incoming QoS 2 message, which has sent the PUBREC, but waiting to receive the PUBREL for it. - 9 - For an incoming QoS 2 message, which has received the PUBREL, but prior to sending the PUBCOMP for it. When the PUBCOMP is sent, the state will change to 10. - 10 - Message successfully received. The [MessageReceived](#messagereceived-event-mqttbroker-control) event fires when the message has completed the acknowledgment process with the client, depending on the QoS level. ### Outgoing Messages The MQTTBroker control will automatically forward received messages to any subscribed clients. Events can be used to record the state of any incoming messages. The [MessageSending](#messagesending-event-mqttbroker-control) event fires when a message is initially sent to a client and contains message metadata. The [OutgoingMessageStatus](#outgoingmessagestatus-event-mqttbroker-control) event fires each time an outgoing message's state is updated. - MessageId: A unique identifier for this message. - DUP: Whether or not the server has indicated that this message is a duplicate of another message sent previously. - QoS: The message's QoS level. - Retain: Whether or not this message is a retained message. - PacketId: The message packet Id. This will always be -1 if QoS is 0. - State: Information about the outgoing message's state. - 1 - Outgoing message is waiting to be sent - 2 - For an outgoing QoS 1 message, which has been sent to the client and waiting for the PUBACK. When the PUBACK is received, the state will change to 10. - 3 - For an outgoing QoS 2 message, which has been sent to the client and waiting for the PUBREC. - 4 - For an outgoing QoS 2 message, which has received the PUBREC, prior to sending the PUBREL for it. - 5 - For an outgoing QoS 2 message, which has sent the PUBREL. When the PUBCOMP is received, the state will change to 10. - 10 - Message successfully sent. ### Saving and Loading Sessions The [SaveSession](#savesession-method-mqttbroker-control) method saves the current state of a client session, including message queues and subscription data, for later retrieval. [SaveSession](#savesession-method-mqttbroker-control) returns a JSON string representing the client's subscriptions and messages. This can later be loaded via [LoadSession](#loadsession-method-mqttbroker-control) to restore the client's state. The format should be a JSON string with the following parameters: ```csharp string sessiondata = broker.SaveSession("Client1"); // sessiondata may contain a JSON string with information like this: { "ClientId":"Client1", "Subscriptions":[{ // A collection of the client's subscribed topics "Topic":"topic name", "QoS":2, }], "IncomingMessages": [{ // A collection of incoming messages "MessageId":1, // The incoming message's ID "Topic":"A", // The incoming message's topic "Payload":"54657374", // hexadecimal message payload "QoS":2, // The incoming message's QoS level "DUP":false, // Whether this message is a duplicate "Retain":false, // Whether this is a retained message "PacketId":1, // This message's packet ID "State":3 // See IncomingMessageStatus event for State details }], "OutgoingMessages":[{ // A collection of outgoing messages "MessageId":2, "Topic":"A", "Payload":"54657374", "QoS":2, "DUP":false, "Retain":false, "PacketId":2, "State":3 // See OutgoingMessageStatus event for State details }] } // Later, the LoadSession method can be used to load the session data broker.LoadSession(sessiondata); ``` ## Property List *The following is the full list of the properties of the control with short descriptions. Click on the links for further details.* | | | | --- | --- | | [ConnectionCount](#connectioncount-property-mqttbroker-control) | The number of records in the Connection arrays. | | [ConnectionClientId](#connectionclientid-property-mqttbroker-control) | A unique identifier for the client. | | [ConnectionId](#connectionid-property-mqttbroker-control) | This property contains an identifier generated by the control to identify each connection. | | [ConnectionKeepAlive](#connectionkeepalive-property-mqttbroker-control) | When set to 1, KEEPALIVE packets are enabled (for long connections). | | [ConnectionLocalHost](#connectionlocalhost-property-mqttbroker-control) | This property shows the IP address of the interface through which the connection is passing. | | [ConnectionLocalPort](#connectionlocalport-property-mqttbroker-control) | This property shows the Transmission Control Protocol (TCP) port on the local host through which the connection is passing. | | [ConnectionProtocol](#connectionprotocol-property-mqttbroker-control) | The protocol of the connected client. | | [ConnectionRemoteHost](#connectionremotehost-property-mqttbroker-control) | This property shows the IP address of the remote host through which the connection is coming. | | [ConnectionRemotePort](#connectionremoteport-property-mqttbroker-control) | This property shows the Transmission Control Protocol (TCP) port on the remote host through which the connection is coming. | | [ConnectionUserName](#connectionusername-property-mqttbroker-control) | The username for this connected client. | | [DefaultIdleTimeout](#defaultidletimeout-property-mqttbroker-control) | This property includes the default idle timeout for inactive clients. | | [ListenerCount](#listenercount-property-mqttbroker-control) | The number of records in the Listener arrays. | | [ListenerLocalHost](#listenerlocalhost-property-mqttbroker-control) | The name of the local host or user-assigned IP interface through which connections are initiated or accepted. | | [ListenerLocalPort](#listenerlocalport-property-mqttbroker-control) | This property includes the port in the local host for this listener. | | [ListenerProtocol](#listenerprotocol-property-mqttbroker-control) | The control supports the following protocols: 0 (mbpTCP) Plaintext TCP 1 (mbpTLS) SSL/TLS over TCP 2 (mbpWS) Plaintext WebSocket 3 (mbpWSS) SSL/TLS over WebSocket . | | [ListenerSSLAuthenticateClients](#listenersslauthenticateclients-property-mqttbroker-control) | If set to True, the server asks the client(s) for a certificate. | | [ListenerSSLCertStore](#listenersslcertstore-property-mqttbroker-control) | The name of the certificate store for the listener's certificate. | | [ListenerSSLCertStorePassword](#listenersslcertstorepassword-property-mqttbroker-control) | This is the password of the SSL certificate. | | [ListenerSSLCertStoreType](#listenersslcertstoretype-property-mqttbroker-control) | This is the type of certificate store for this certificate. | | [ListenerSSLCertSubject](#listenersslcertsubject-property-mqttbroker-control) | The subject of the SSL certificate. | | [Listening](#listening-property-mqttbroker-control) | This property indicates whether the control is listening for incoming connections on LocalPort. | | [MessageCount](#messagecount-property-mqttbroker-control) | The number of records in the Message arrays. | | [MessageId](#messageid-property-mqttbroker-control) | Message identifier used to associate the message state. | | [MessagePayload](#messagepayload-property-mqttbroker-control) | This message's raw data payload. | | [MessageTopic](#messagetopic-property-mqttbroker-control) | This message's topic. | | [SessionCount](#sessioncount-property-mqttbroker-control) | The number of records in the Session arrays. | | [SessionClientId](#sessionclientid-property-mqttbroker-control) | A unique identifier for the client. | | [SessionIncomingMessages](#sessionincomingmessages-property-mqttbroker-control) | A collection of incoming messages. | | [SessionOutgoingMessages](#sessionoutgoingmessages-property-mqttbroker-control) | A collection of outgoing messages. | | [SessionSubGrantedQoS](#sessionsubgrantedqos-property-mqttbroker-control) | The subscription's granted QoS level for the client. | | [SessionSubTopicFilters](#sessionsubtopicfilters-property-mqttbroker-control) | The subscription topic filters for this client session. | | [SSLProvider](#sslprovider-property-mqttbroker-control) | The Secure Sockets Layer/Transport Layer Security (SSL/TLS) implementation to use. | ## Method List *The following is the full list of the methods of the control with short descriptions. Click on the links for further details.* | | | | --- | --- | | [AddBrokerListener](#addbrokerlistener-method-mqttbroker-control) | Creates a new listener for the broker service. | | [Config](#config-method-mqttbroker-control) | Sets or retrieves a configuration setting. | | [Disconnect](#disconnect-method-mqttbroker-control) | This method disconnects the specified client. | | [DoEvents](#doevents-method-mqttbroker-control) | This method processes events from the internal message queue. | | [Interrupt](#interrupt-method-mqttbroker-control) | This method interrupts a synchronous send to the remote host. | | [LoadSession](#loadsession-method-mqttbroker-control) | Restores session data for a specified client, enabling resumption of pending operations or message delivery. | | [Reset](#reset-method-mqttbroker-control) | This method will reset the control. | | [SaveSession](#savesession-method-mqttbroker-control) | Saves the current state of a client session, including message queues and subscription data, for later retrieval. | | [Shutdown](#shutdown-method-mqttbroker-control) | This method shuts down the server. | | [StartListening](#startlistening-method-mqttbroker-control) | This method starts listening for incoming connections. | | [StopListening](#stoplistening-method-mqttbroker-control) | This method stops listening for new connections. | ## Event List *The following is the full list of the events fired by the control with short descriptions. Click on the links for further details.* | | | | --- | --- | | [Connected](#connected-event-mqttbroker-control) | This event is fired immediately after a connection completes (or fails). | | [ConnectionRequest](#connectionrequest-event-mqttbroker-control) | This event is fired when a request for connection comes from a remote host. | | [Disconnected](#disconnected-event-mqttbroker-control) | This event is fired when a connection is closed. | | [Error](#error-event-mqttbroker-control) | This event fires information about errors during data delivery. | | [IncomingMessageStatus](#incomingmessagestatus-event-mqttbroker-control) | Fires when an incoming message's state is updated. | | [Log](#log-event-mqttbroker-control) | Fires once for each log message. | | [MessageReceived](#messagereceived-event-mqttbroker-control) | Fires when a new message is received from a client. | | [MessageReceiving](#messagereceiving-event-mqttbroker-control) | Fires when a message is initially received from a client. | | [MessageSending](#messagesending-event-mqttbroker-control) | Fires when a message is initially sent to a client. | | [MessageSent](#messagesent-event-mqttbroker-control) | Fires after a message is successfully delivered to a client, confirming transmission. | | [OutgoingMessageStatus](#outgoingmessagestatus-event-mqttbroker-control) | Fired to provide the current delivery status of an outgoing message. Includes success or failure metadata. | | [SessionRemoved](#sessionremoved-event-mqttbroker-control) | Fired when a client session is removed, indicating all resources associated with the session are cleaned up. | | [SessionRequest](#sessionrequest-event-mqttbroker-control) | Fires when a new session is requested. | | [SSLClientAuthentication](#sslclientauthentication-event-mqttbroker-control) | This event is fired when the client presents its credentials to the server. | | [SSLStatus](#sslstatus-event-mqttbroker-control) | This event is fired to show the progress of the secure connection. | | [Subscribe](#subscribe-event-mqttbroker-control) | Fires when a client requests to subscribe to a topic. | | [Unsubscribe](#unsubscribe-event-mqttbroker-control) | Fires when a client unsubscribes from a topic, removing its subscription data. | ## Config Settings *The following is a list of config settings for the control with short descriptions. Click on the links for further details.* | | | | --- | --- | | [ConnectionTimeout](#ConnectionTimeout) | Sets a separate timeout value for establishing a connection. | | [EnableFallback](#EnableFallback) | Whether to try the other addresses the remote host resolves to when a connection attempt fails. | | [FallbackTimeout](#FallbackTimeout) | The maximum time in milliseconds to spend on connection attempts when EnableFallback is enabled. | | [FirewallAutoDetect](#FirewallAutoDetect) | Tells the control whether or not to automatically detect and use firewall system settings, if available. | | [FirewallHost](#FirewallHost) | Name or IP address of firewall (optional). | | [FirewallHTTPVersion](#FirewallHTTPVersion) | The HTTP version to be used when connecting through a tunneling proxy. | | [FirewallPassword](#FirewallPassword) | Password to be used if authentication is to be used when connecting through the firewall. | | [FirewallPort](#FirewallPort) | The TCP port for the FirewallHost;. | | [FirewallType](#FirewallType) | Determines the type of firewall to connect through. | | [FirewallUser](#FirewallUser) | A user name if authentication is to be used connecting through a firewall. | | [KeepAliveInterval](#KeepAliveInterval) | The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received. | | [KeepAliveTime](#KeepAliveTime) | The inactivity time in milliseconds before a TCP keep-alive packet is sent. | | [Linger](#Linger) | When set to True, connections are terminated gracefully. | | [LingerTime](#LingerTime) | Time in seconds to have the connection linger. | | [LocalHost](#LocalHost) | The name of the local host through which connections are initiated or accepted. | | [LocalPort](#LocalPort) | The port in the local host where the control binds. | | [MaxLineLength](#MaxLineLength) | The maximum amount of data to accumulate when no EOL is found. | | [MaxTransferRate](#MaxTransferRate) | The transfer rate limit in bytes per second. | | [ProxyExceptionsList](#ProxyExceptionsList) | A semicolon separated list of hosts and IPs to bypass when using a proxy. | | [TCPKeepAlive](#TCPKeepAlive) | Determines whether or not the keep alive socket option is enabled. | | [TcpNoDelay](#TcpNoDelay) | Whether or not to delay when sending packets. | | [UseIPv6](#UseIPv6) | Whether to use IPv6. | | [UseNTLMv2](#UseNTLMv2) | Whether to use NTLM V2. | | [LogSSLPackets](#LogSSLPackets) | Controls whether SSL packets are logged when using the internal security API. | | [OpenSSLCADir](#OpenSSLCADir) | The path to a directory containing CA certificates. | | [OpenSSLCAFile](#OpenSSLCAFile) | Name of the file containing the list of CA's trusted by your application. | | [OpenSSLCipherList](#OpenSSLCipherList) | A string that controls the ciphers to be used by SSL. | | [OpenSSLPrngSeedData](#OpenSSLPrngSeedData) | The data to seed the pseudo random number generator (PRNG). | | [ReuseSSLSession](#ReuseSSLSession) | Determines if the SSL session is reused. | | [SSLCACerts](#SSLCACerts) | A newline separated list of CA certificates to be included when performing an SSL handshake. | | [SSLCheckCRL](#SSLCheckCRL) | Whether to check the Certificate Revocation List for the server certificate. | | [SSLCheckOCSP](#SSLCheckOCSP) | Whether to use OCSP to check the status of the server certificate. | | [SSLCipherStrength](#SSLCipherStrength) | The minimum cipher strength used for bulk encryption. | | [SSLClientCACerts](#SSLClientCACerts) | A newline separated list of CA certificates to use during SSL client certificate validation. | | [SSLEnabledCipherSuites](#SSLEnabledCipherSuites) | The cipher suite to be used in an SSL negotiation. | | [SSLEnabledProtocols](#SSLEnabledProtocols) | Used to enable/disable the supported security protocols. | | [SSLEnableRenegotiation](#SSLEnableRenegotiation) | Whether the renegotiation_info SSL extension is supported. | | [SSLIncludeCertChain](#SSLIncludeCertChain) | Whether the entire certificate chain is included in the SSLServerAuthentication event. | | [SSLKeyLogFile](#SSLKeyLogFile) | The location of a file where per-session secrets are written for debugging purposes. | | [SSLNegotiatedCipher](#SSLNegotiatedCipher) | Returns the negotiated cipher suite. | | [SSLNegotiatedCipherStrength](#SSLNegotiatedCipherStrength) | Returns the negotiated cipher suite strength. | | [SSLNegotiatedCipherSuite](#SSLNegotiatedCipherSuite) | Returns the negotiated cipher suite. | | [SSLNegotiatedKeyExchange](#SSLNegotiatedKeyExchange) | Returns the negotiated key exchange algorithm. | | [SSLNegotiatedKeyExchangeStrength](#SSLNegotiatedKeyExchangeStrength) | Returns the negotiated key exchange algorithm strength. | | [SSLNegotiatedVersion](#SSLNegotiatedVersion) | Returns the negotiated protocol version. | | [SSLSecurityFlags](#SSLSecurityFlags) | Flags that control certificate verification. | | [SSLServerCACerts](#SSLServerCACerts) | A newline separated list of CA certificates to use during SSL server certificate validation. | | [TLS12SignatureAlgorithms](#TLS12SignatureAlgorithms) | Defines the allowed TLS 1.2 signature algorithms when SSLProvider is set to Internal. | | [TLS12SupportedGroups](#TLS12SupportedGroups) | The supported groups for ECC. | | [TLS13KeyShareGroups](#TLS13KeyShareGroups) | The groups for which to pregenerate key shares. | | [TLS13SignatureAlgorithms](#TLS13SignatureAlgorithms) | The allowed certificate signature algorithms. | | [TLS13SupportedGroups](#TLS13SupportedGroups) | The supported groups for (EC)DHE key exchange. | | [AbsoluteTimeout](#AbsoluteTimeout) | Determines whether timeouts are inactivity timeouts or absolute timeouts. | | [FirewallData](#FirewallData) | Used to send extra data to the firewall. | | [InBufferSize](#InBufferSize) | The size in bytes of the incoming queue of the socket. | | [OutBufferSize](#OutBufferSize) | The size in bytes of the outgoing queue of the socket. | | [CodePage](#CodePage) | The system code page used for Unicode to Multibyte translations. | | [MaskSensitiveData](#MaskSensitiveData) | Whether sensitive data is masked in log messages. | | [UseInternalSecurityAPI](#UseInternalSecurityAPI) | Whether or not to use the system security libraries or an internal implementation. | # ConnectionCount Property ([MQTTBroker](#mqttbroker-control) Control) The number of records in the Connection arrays. ## Syntax ```text mqttbrokercontrol.ConnectionCount ``` ## Default Value 0 ## Remarks This property controls the size of the following arrays: - [ConnectionClientId](#connectionclientid-property-mqttbroker-control) - [ConnectionId](#connectionid-property-mqttbroker-control) - [ConnectionKeepAlive](#connectionkeepalive-property-mqttbroker-control) - [ConnectionLocalHost](#connectionlocalhost-property-mqttbroker-control) - [ConnectionLocalPort](#connectionlocalport-property-mqttbroker-control) - [ConnectionProtocol](#connectionprotocol-property-mqttbroker-control) - [ConnectionRemoteHost](#connectionremotehost-property-mqttbroker-control) - [ConnectionRemotePort](#connectionremoteport-property-mqttbroker-control) - [ConnectionUserName](#connectionusername-property-mqttbroker-control) The array indices start at *0* and end at *ConnectionCount - 1*. This property is read-only and not available at design time. ## Data Type Integer # ConnectionClientId Property ([MQTTBroker](#mqttbroker-control) Control) A unique identifier for the client. ## Syntax ```text mqttbrokercontrol.ConnectionClientId(ConnectionId) ``` ## Default Value "" ## Remarks A unique identifier for the client. The *ConnectionId* parameter specifies the index of the item in the array. The size of the array is controlled by the [ConnectionCount](#connectioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type String # ConnectionId Property ([MQTTBroker](#mqttbroker-control) Control) This property contains an identifier generated by the control to identify each connection. ## Syntax ```text mqttbrokercontrol.ConnectionId(ConnectionId) ``` ## Default Value 0 ## Remarks This field contains an identifier generated by the component to identify each connection. This identifier is unique to this connection. The *ConnectionId* parameter specifies the index of the item in the array. The size of the array is controlled by the [ConnectionCount](#connectioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type Integer # ConnectionKeepAlive Property ([MQTTBroker](#mqttbroker-control) Control) When set to 1, KEEPALIVE packets are enabled (for long connections). ## Syntax ```text mqttbrokercontrol.ConnectionKeepAlive(ConnectionId) ``` ## Default Value 0 ## Remarks When set to 1, KEEPALIVE packets are enabled (for long connections). This property enables the SO_KEEPALIVE option on the incoming connections. This option prevents long connections from timing out in case of inactivity. NOTE: System Transmission Control Protocol (TCP)/IP stack implementations are not required to support SO_KEEPALIVE. This property is shared among incoming connections. When the property is set, the corresponding value is set for incoming connections as they are accepted. Existing connections are not modified. The *ConnectionId* parameter specifies the index of the item in the array. The size of the array is controlled by the [ConnectionCount](#connectioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type Integer # ConnectionLocalHost Property ([MQTTBroker](#mqttbroker-control) Control) This property shows the IP address of the interface through which the connection is passing. ## Syntax ```text mqttbrokercontrol.ConnectionLocalHost(ConnectionId) ``` ## Default Value "" ## Remarks This field shows the IP address of the interface through which the connection is passing. LocalAddress is important for multihomed hosts so that it can be used to find the particular network interface through which an individual connection is going. The *ConnectionId* parameter specifies the index of the item in the array. The size of the array is controlled by the [ConnectionCount](#connectioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type String # ConnectionLocalPort Property ([MQTTBroker](#mqttbroker-control) Control) This property shows the Transmission Control Protocol (TCP) port on the local host through which the connection is passing. ## Syntax ```text mqttbrokercontrol.ConnectionLocalPort(ConnectionId) ``` ## Default Value 0 ## Remarks This field shows the Transmission Control Protocol (TCP) port on the local host through which the connection is passing. The *ConnectionId* parameter specifies the index of the item in the array. The size of the array is controlled by the [ConnectionCount](#connectioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type Integer # ConnectionProtocol Property ([MQTTBroker](#mqttbroker-control) Control) The protocol of the connected client. ## Syntax ```text mqttbrokercontrol.ConnectionProtocol(ConnectionId) ``` ## Possible Values ```text mbpTCP(0), mbpTLS(1), mbpWS(2), mbpWSS(3) ``` ## Default Value 0 ## Remarks The protocol of the connected client. The control supports the following protocols: | | | | --- | --- | | 0 (mbpTCP) | Plaintext TCP | | 1 (mbpTLS) | SSL/TLS over TCP | | 2 (mbpWS) | Plaintext WebSocket | | 3 (mbpWSS) | SSL/TLS over WebSocket | The *ConnectionId* parameter specifies the index of the item in the array. The size of the array is controlled by the [ConnectionCount](#connectioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type Integer # ConnectionRemoteHost Property ([MQTTBroker](#mqttbroker-control) Control) This property shows the IP address of the remote host through which the connection is coming. ## Syntax ```text mqttbrokercontrol.ConnectionRemoteHost(ConnectionId) ``` ## Default Value "" ## Remarks This field shows the IP address of the remote host through which the connection is coming. The connection must be valid or an error will be fired. If the component is configured to use a SOCKS firewall, the value assigned to this property may be preceded with an "*". If this is the case, the host name is passed to the firewall unresolved and the firewall performs the DNS resolution. The *ConnectionId* parameter specifies the index of the item in the array. The size of the array is controlled by the [ConnectionCount](#connectioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type String # ConnectionRemotePort Property ([MQTTBroker](#mqttbroker-control) Control) This property shows the Transmission Control Protocol (TCP) port on the remote host through which the connection is coming. ## Syntax ```text mqttbrokercontrol.ConnectionRemotePort(ConnectionId) ``` ## Default Value 0 ## Remarks This field shows the Transmission Control Protocol (TCP) port on the remote host through which the connection is coming. The connection must be valid or an error will be fired. The *ConnectionId* parameter specifies the index of the item in the array. The size of the array is controlled by the [ConnectionCount](#connectioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type Integer # ConnectionUserName Property ([MQTTBroker](#mqttbroker-control) Control) The username for this connected client. ## Syntax ```text mqttbrokercontrol.ConnectionUserName(ConnectionId) ``` ## Default Value "" ## Remarks The username for this connected client. The *ConnectionId* parameter specifies the index of the item in the array. The size of the array is controlled by the [ConnectionCount](#connectioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type String # DefaultIdleTimeout Property ([MQTTBroker](#mqttbroker-control) Control) This property includes the default idle timeout for inactive clients. ## Syntax ```text mqttbrokercontrol.DefaultIdleTimeout[=integer] ``` ## Default Value 0 ## Remarks This property specifies the idle timeout (in seconds) for clients. When set to a positive value, the control will disconnect idle clients after the specified timeout. This applies only to clients that have not sent or received data within DefaultIdleTimeout seconds. If set to 0 (default), no idle timeout is applied. NOTE: [DoEvents](#doevents-method-mqttbroker-control) must be called for the control to check existing connections. ## Data Type Integer # ListenerCount Property ([MQTTBroker](#mqttbroker-control) Control) The number of records in the Listener arrays. ## Syntax ```text mqttbrokercontrol.ListenerCount ``` ## Default Value 0 ## Remarks This property controls the size of the following arrays: - [ListenerLocalHost](#listenerlocalhost-property-mqttbroker-control) - [ListenerLocalPort](#listenerlocalport-property-mqttbroker-control) - [ListenerProtocol](#listenerprotocol-property-mqttbroker-control) - [ListenerSSLAuthenticateClients](#listenersslauthenticateclients-property-mqttbroker-control) - [ListenerSSLCertStore](#listenersslcertstore-property-mqttbroker-control) - [ListenerSSLCertStorePassword](#listenersslcertstorepassword-property-mqttbroker-control) - [ListenerSSLCertStoreType](#listenersslcertstoretype-property-mqttbroker-control) - [ListenerSSLCertSubject](#listenersslcertsubject-property-mqttbroker-control) The array indices start at *0* and end at *ListenerCount - 1*. This property is read-only and not available at design time. ## Data Type Integer # ListenerLocalHost Property ([MQTTBroker](#mqttbroker-control) Control) The name of the local host or user-assigned IP interface through which connections are initiated or accepted. ## Syntax ```text mqttbrokercontrol.ListenerLocalHost(ListenerIndex) ``` ## Default Value "" ## Remarks The name of the local host or user-assigned IP interface through which connections are initiated or accepted. The *ListenerIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [ListenerCount](#listenercount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type String # ListenerLocalPort Property ([MQTTBroker](#mqttbroker-control) Control) This property includes the port in the local host for this listener. ## Syntax ```text mqttbrokercontrol.ListenerLocalPort(ListenerIndex) ``` ## Default Value 0 ## Remarks This field includes the port in the local host for this listener. The *ListenerIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [ListenerCount](#listenercount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type Integer # ListenerProtocol Property ([MQTTBroker](#mqttbroker-control) Control) The control supports the following protocols: 0 (mbpTCP) Plaintext TCP 1 (mbpTLS) SSL/TLS over TCP 2 (mbpWS) Plaintext WebSocket 3 (mbpWSS) SSL/TLS over WebSocket . ## Syntax ```text mqttbrokercontrol.ListenerProtocol(ListenerIndex) ``` ## Possible Values ```text mbpTCP(0), mbpTLS(1), mbpWS(2), mbpWSS(3) ``` ## Default Value 0 ## Remarks The control supports the following protocols: | | | | --- | --- | | 0 (mbpTCP) | Plaintext TCP | | 1 (mbpTLS) | SSL/TLS over TCP | | 2 (mbpWS) | Plaintext WebSocket | | 3 (mbpWSS) | SSL/TLS over WebSocket | The *ListenerIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [ListenerCount](#listenercount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type Integer # ListenerSSLAuthenticateClients Property ([MQTTBroker](#mqttbroker-control) Control) If set to True, the server asks the client(s) for a certificate. ## Syntax ```text mqttbrokercontrol.ListenerSSLAuthenticateClients(ListenerIndex) ``` ## Default Value False ## Remarks If set to True, the server asks the client(s) for a certificate. This is used in conjunction with the SSLClientAuthentication event. Please refer to the documentation of the SSLClientAuthentication event for details. The *ListenerIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [ListenerCount](#listenercount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type Boolean # ListenerSSLCertStore Property ([MQTTBroker](#mqttbroker-control) Control) The name of the certificate store for the listener's certificate. ## Syntax ```text mqttbrokercontrol.ListenerSSLCertStore(ListenerIndex) ``` ## Default Value "MY" ## Remarks The name of the certificate store for the listener's certificate. The [ListenerStoreType](#MQTTBroker_p_ListenerStoreType) property denotes the type of the certificate store specified by [ListenerStore](#MQTTBroker_p_ListenerStore). If the store is password-protected, specify the password in [ListenerStorePassword](#MQTTBroker_p_ListenerStorePassword). [ListenerStore](#MQTTBroker_p_ListenerStore) is used in conjunction with the [ListenerSubject](#MQTTBroker_p_ListenerSubject) property to specify client certificates. If [ListenerStore](#MQTTBroker_p_ListenerStore) has a value, and [ListenerSubject](#MQTTBroker_p_ListenerSubject) or [ListenerEncoded](#MQTTBroker_p_ListenerEncoded) is set, a search for a certificate is initiated. Please see the [ListenerSubject](#MQTTBroker_p_ListenerSubject) property for details. Designations of certificate stores are platform dependent. The following designations are the most common User and Machine certificate stores in Windows: | | | | --- | --- | | MY | A certificate store holding personal certificates with their associated private keys. | | CA | Certifying authority certificates. | | ROOT | Root certificates. | When the certificate store type is *cstPFXFile*, this property must be set to the name of the file. When the type is *cstPFXBlob*, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store). The *ListenerIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [ListenerCount](#listenercount-property-mqttbroker-control) property. To read or write binary data to the property, a Variant (Byte Array) version is provided in **.ListenerSSLCertStoreB**. This property is read-only and not available at design time. ## Data Type Binary String # ListenerSSLCertStorePassword Property ([MQTTBroker](#mqttbroker-control) Control) This is the password of the SSL certificate. ## Syntax ```text mqttbrokercontrol.ListenerSSLCertStorePassword(ListenerIndex) ``` ## Default Value "" ## Remarks This is the password of the SSL certificate. The *ListenerIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [ListenerCount](#listenercount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type String # ListenerSSLCertStoreType Property ([MQTTBroker](#mqttbroker-control) Control) This is the type of certificate store for this certificate. ## Syntax ```text mqttbrokercontrol.ListenerSSLCertStoreType(ListenerIndex) ``` ## Possible Values ```text cstUser(0), cstMachine(1), cstPFXFile(2), cstPFXBlob(3), cstJKSFile(4), cstJKSBlob(5), cstPEMKeyFile(6), cstPEMKeyBlob(7), cstPublicKeyFile(8), cstPublicKeyBlob(9), cstSSHPublicKeyBlob(10), cstP7BFile(11), cstP7BBlob(12), cstSSHPublicKeyFile(13), cstPPKFile(14), cstPPKBlob(15), cstXMLFile(16), cstXMLBlob(17), cstJWKFile(18), cstJWKBlob(19), cstSecurityKey(20), cstBCFKSFile(21), cstBCFKSBlob(22), cstPKCS11(23), cstAuto(99) ``` ## Default Value 0 ## Remarks This is the type of certificate store for this certificate. Designations of certificate stores are platform dependent. The following designations are the most common User and Machine certificate stores in Windows: | | | | --- | --- | | MY | A certificate store holding personal certificates with their associated private keys. | | CA | Certifying authority certificates. | | ROOT | Root certificates. | When the certificate store type is *cstPFXFile*, this property must be set to the name of the file. When the type is *cstPFXBlob*, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store). The *ListenerIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [ListenerCount](#listenercount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type Integer # ListenerSSLCertSubject Property ([MQTTBroker](#mqttbroker-control) Control) The subject of the SSL certificate. ## Syntax ```text mqttbrokercontrol.ListenerSSLCertSubject(ListenerIndex) ``` ## Default Value "" ## Remarks The subject of the SSL certificate. The certificate subject is a comma-separated list of distinguished name fields and values. For instance, "CN=www.server.com, OU=test, C=US, E=example@email.com". Common fields and their meanings are as follows: | Field | Meaning | | --- | --- | | CN | Common Name. This is commonly a hostname like www.server.com. | | O | Organization | | OU | Organizational Unit | | L | Locality | | S | State | | C | Country | | E | Email Address | If a field value contains a comma, it must be quoted. The *ListenerIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [ListenerCount](#listenercount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type String # Listening Property ([MQTTBroker](#mqttbroker-control) Control) This property indicates whether the control is listening for incoming connections on LocalPort. ## Syntax ```text mqttbrokercontrol.Listening ``` ## Default Value False ## Remarks This property indicates whether the control is listening for connections on the port specified by the LocalPort property. Use the [StartListening](#startlistening-method-mqttbroker-control) and [StopListening](#stoplistening-method-mqttbroker-control) methods to control whether the control is listening. This property is read-only and not available at design time. ## Data Type Boolean # MessageCount Property ([MQTTBroker](#mqttbroker-control) Control) The number of records in the Message arrays. ## Syntax ```text mqttbrokercontrol.MessageCount ``` ## Default Value 0 ## Remarks This property controls the size of the following arrays: - [MessageId](#messageid-property-mqttbroker-control) - [MessagePayload](#messagepayload-property-mqttbroker-control) - [MessageTopic](#messagetopic-property-mqttbroker-control) The array indices start at *0* and end at *MessageCount - 1*. This property is read-only and not available at design time. ## Data Type Integer # MessageId Property ([MQTTBroker](#mqttbroker-control) Control) Message identifier used to associate the message state. ## Syntax ```text mqttbrokercontrol.MessageId(MessageIndex) ``` ## Default Value 0 ## Remarks Message identifier used to associate the message state. The *MessageIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [MessageCount](#messagecount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type Long64 # MessagePayload Property ([MQTTBroker](#mqttbroker-control) Control) This message's raw data payload. ## Syntax ```text mqttbrokercontrol.MessagePayload(MessageIndex) ``` ## Default Value "" ## Remarks This message's raw data payload. The *MessageIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [MessageCount](#messagecount-property-mqttbroker-control) property. To read or write binary data to the property, a Variant (Byte Array) version is provided in **.MessagePayloadB**. This property is read-only and not available at design time. ## Data Type Binary String # MessageTopic Property ([MQTTBroker](#mqttbroker-control) Control) This message's topic. ## Syntax ```text mqttbrokercontrol.MessageTopic(MessageIndex) ``` ## Default Value "" ## Remarks This message's topic. The *MessageIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [MessageCount](#messagecount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type String # SessionCount Property ([MQTTBroker](#mqttbroker-control) Control) The number of records in the Session arrays. ## Syntax ```text mqttbrokercontrol.SessionCount ``` ## Default Value 0 ## Remarks This property controls the size of the following arrays: - [SessionClientId](#sessionclientid-property-mqttbroker-control) - [SessionIncomingMessages](#sessionincomingmessages-property-mqttbroker-control) - [SessionOutgoingMessages](#sessionoutgoingmessages-property-mqttbroker-control) - [SessionSubGrantedQoS](#sessionsubgrantedqos-property-mqttbroker-control) - [SessionSubTopicFilters](#sessionsubtopicfilters-property-mqttbroker-control) The array indices start at *0* and end at *SessionCount - 1*. This property is read-only and not available at design time. ## Data Type Integer # SessionClientId Property ([MQTTBroker](#mqttbroker-control) Control) A unique identifier for the client. ## Syntax ```text mqttbrokercontrol.SessionClientId(SessionIndex) ``` ## Default Value "" ## Remarks A unique identifier for the client. The *SessionIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [SessionCount](#sessioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type String # SessionIncomingMessages Property ([MQTTBroker](#mqttbroker-control) Control) A collection of incoming messages. ## Syntax ```text mqttbrokercontrol.SessionIncomingMessages(SessionIndex) ``` ## Default Value "" ## Remarks A collection of incoming messages. The *SessionIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [SessionCount](#sessioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type String # SessionOutgoingMessages Property ([MQTTBroker](#mqttbroker-control) Control) A collection of outgoing messages. ## Syntax ```text mqttbrokercontrol.SessionOutgoingMessages(SessionIndex) ``` ## Default Value "" ## Remarks A collection of outgoing messages. The *SessionIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [SessionCount](#sessioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type String # SessionSubGrantedQoS Property ([MQTTBroker](#mqttbroker-control) Control) The subscription's granted QoS level for the client. ## Syntax ```text mqttbrokercontrol.SessionSubGrantedQoS(SessionIndex) ``` ## Default Value "" ## Remarks The subscription's granted QoS level for the client. The *SessionIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [SessionCount](#sessioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type String # SessionSubTopicFilters Property ([MQTTBroker](#mqttbroker-control) Control) The subscription topic filters for this client session. ## Syntax ```text mqttbrokercontrol.SessionSubTopicFilters(SessionIndex) ``` ## Default Value "" ## Remarks The subscription topic filters for this client session. The *SessionIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [SessionCount](#sessioncount-property-mqttbroker-control) property. This property is read-only and not available at design time. ## Data Type String # SSLProvider Property ([MQTTBroker](#mqttbroker-control) Control) The Secure Sockets Layer/Transport Layer Security (SSL/TLS) implementation to use. ## Syntax ```text mqttbrokercontrol.SSLProvider[=integer] ``` ## Possible Values ```text sslpAutomatic(0), sslpPlatform(1), sslpInternal(2) ``` ## Default Value 0 ## Remarks This property specifies the SSL/TLS implementation to use. In most cases the default value of *0* (Automatic) is recommended and should not be changed. When set to *0* (Automatic), the control will select whether to use the platform implementation or the internal implementation depending on the operating system as well as the TLS version being used. Possible values are as follows: | | | | --- | --- | | 0 (sslpAutomatic - default) | Automatically selects the appropriate implementation. | | 1 (sslpPlatform) | Uses the platform/system implementation. | | 2 (sslpInternal) | Uses the internal implementation. | **Additional Notes** In most cases using the default value (Automatic) is recommended. The control will select a provider depending on the current platform. When Automatic is selected, the platform implementation is used by default. When TLS 1.3 is enabled via [SSLEnabledProtocols](#SSLEnabledProtocols), the control will always try and use the platform implementation. If the platform TLS 1.3 implementation is not available, the internal implementation will be used. ## Data Type Integer # AddBrokerListener Method ([MQTTBroker](#mqttbroker-control) Control) Creates a new listener for the broker service. ## Syntax ```text mqttbrokercontrol.AddBrokerListener LocalHost, LocalPort, Protocol, SSLCertStoreType, SSLCertStore, SSLCertStorePassword, SSLCertSubject ``` ## Remarks *AddBrokerListener* adds a new listener to the Listeners collection. Any listeners must be configured before starting the broker. Multiple protocols can be supported by adding different listeners. The control supports the following protocols: | | | | --- | --- | | 0 (mbpTCP) | Plaintext TCP | | 1 (mbpTLS) | SSL/TLS over TCP | | 2 (mbpWS) | Plaintext WebSocket | | 3 (mbpWSS) | SSL/TLS over WebSocket | Certificate details can be provided via the following parameters: | | | | --- | --- | | SSLCertStoreType | The type of certificate store for this certificate. | | SSLCertStore | The name of the certificate store for the client certificate. This can be null for plaintext. | | SSLCertStorePassword | If the type of certificate store requires a password, this field is used to specify the password needed to open the certificate store. | | SSLCertSubject | The subject of the certificate used for client authentication. | Multiple protocols can be enabled (each on a different port): ```csharp // Plaintext TCP mqttbroker.AddBrokerListener("127.0.0.1", PLAIN_PORT, (int)MQTTBrokerProtocols.mbpTCP, 0, null, null, null); // TCP with TLS mqttbroker.AddBrokerListener("127.0.0.1", SSL_PORT, (int)MQTTBrokerProtocols.mbpTLS, (int)CertStoreTypes.cstPFXFile, "test1.pfx", "test", "*"); // Plaintext WebSocket mqttbroker.AddBrokerListener("127.0.0.1", WS_PORT, (int)MQTTBrokerProtocols.mbpWS, 0, null, null, null); // WebSocket with TLS mqttbroker.AddBrokerListener("127.0.0.1", WSS_PORT, (int)MQTTBrokerProtocols.mbpWSS, (int)CertStoreTypes.cstPFXFile, "test2.pfx", "test", "*"); ``` # Config Method ([MQTTBroker](#mqttbroker-control) Control) Sets or retrieves a configuration setting. ## Syntax ```text mqttbrokercontrol.Config ConfigurationString ``` ## Remarks Config is a generic method available in every control. It is used to set and retrieve [configuration settings](#config-settings-mqttbroker-control) for the control. These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the control, access to these *internal properties* is provided through the Config method. To set a configuration setting named *PROPERTY*, you must call *Config("PROPERTY=VALUE")*, where *VALUE* is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter). To read (query) the value of a [configuration setting](#config-settings-mqttbroker-control), you must call *Config("PROPERTY")*. The value will be returned as a string. # Disconnect Method ([MQTTBroker](#mqttbroker-control) Control) This method disconnects the specified client. ## Syntax ```text mqttbrokercontrol.Disconnect ConnectionId ``` ## Remarks Calling this method will disconnect the client specified by the *ConnectionId* parameter. # DoEvents Method ([MQTTBroker](#mqttbroker-control) Control) This method processes events from the internal message queue. ## Syntax ```text mqttbrokercontrol.DoEvents ``` ## Remarks When DoEvents is called, the control processes any available events. If no events are available, it waits for a preset period of time, and then returns. # Interrupt Method ([MQTTBroker](#mqttbroker-control) Control) This method interrupts a synchronous send to the remote host. ## Syntax ```text mqttbrokercontrol.Interrupt ConnectionId ``` ## Remarks This property is called using the Connection Id if you wish to interrupt a connection and stop a file from uploading without disconnecting the client connected to the control. If you use SendFile to upload a file, the control will run synchronously on that Connection Id until it is completed. # LoadSession Method ([MQTTBroker](#mqttbroker-control) Control) Restores session data for a specified client, enabling resumption of pending operations or message delivery. ## Syntax ```text mqttbrokercontrol.LoadSession sessionInfo ``` ## Remarks The LoadSession method is used to load prior client session information if required. This can be used after shutting down a broker to preserve session data and ensure messages can be redelivered once the broker is restarted. The [SaveSession](#savesession-method-mqttbroker-control) method can be used to save session data, and the resulting string can be provided to the LoadSession method. The format should be a JSON string with the following parameters: ```csharp { "ClientId":"Client1", "Subscriptions":[{ // A collection of the client's subscribed topics "Topic":"topic name", "QoS":2, }], "IncomingMessages": [{ // A collection of incoming messages "MessageId":1, // The incoming message's ID "Topic":"A", // The incoming message's topic "Payload":"54657374", // hexadecimal message payload "QoS":2, // The incoming message's QoS level "DUP":false, // Whether this message is a duplicate "Retain":false, // Whether this is a retained message "PacketId":1, // This message's packet ID "State":3 // See IncomingMessageStatus event for State details }], "OutgoingMessages":[{ // A collection of outgoing messages "MessageId":2, "Topic":"A", "Payload":"54657374", "QoS":2, "DUP":false, "Retain":false, "PacketId":2, "State":3 // See OutgoingMessageStatus event for State details }] } ``` **Session data can be saved with [SaveSession](#savesession-method-mqttbroker-control), then later loaded with LoadSession** ```csharp string sessiondata = broker.SaveSession("Client1"); // sessiondata contains session information for Client1 ... broker.LoadSession(sessiondata); ``` # Reset Method ([MQTTBroker](#mqttbroker-control) Control) This method will reset the control. ## Syntax ```text mqttbrokercontrol.Reset ``` ## Remarks This method will reset the control's properties to their default values. # SaveSession Method ([MQTTBroker](#mqttbroker-control) Control) Saves the current state of a client session, including message queues and subscription data, for later retrieval. ## Syntax ```text mqttbrokercontrol.SaveSession clientId ``` ## Remarks Returns a JSON string representing the client's subscriptions and messages. This can later be loaded via [LoadSession](#loadsession-method-mqttbroker-control) to restore the client's state. The format should be a JSON string with the following parameters: ```csharp string sessiondata = broker.SaveSession("Client1"); // sessiondata may contain a JSON string with information like this: { "ClientId":"Client1", "Subscriptions":[{ // A collection of the client's subscribed topics "Topic":"topic name", "QoS":2, }], "IncomingMessages": [{ // A collection of incoming messages "MessageId":1, // The incoming message's ID "Topic":"A", // The incoming message's topic "Payload":"54657374", // hexadecimal message payload "QoS":2, // The incoming message's QoS level "DUP":false, // Whether this message is a duplicate "Retain":false, // Whether this is a retained message "PacketId":1, // This message's packet ID "State":3 // See IncomingMessageStatus event for State details }], "OutgoingMessages":[{ // A collection of outgoing messages "MessageId":2, "Topic":"A", "Payload":"54657374", "QoS":2, "DUP":false, "Retain":false, "PacketId":2, "State":3 // See OutgoingMessageStatus event for State details }] } ``` # Shutdown Method ([MQTTBroker](#mqttbroker-control) Control) This method shuts down the server. ## Syntax ```text mqttbrokercontrol.Shutdown ``` ## Remarks This method shuts down the server. Calling this method is equivalent to calling [StopListening](#stoplistening-method-mqttbroker-control) and then breaking every client connection by calling [Disconnect](#disconnect-method-mqttbroker-control). # StartListening Method ([MQTTBroker](#mqttbroker-control) Control) This method starts listening for incoming connections. ## Syntax ```text mqttbrokercontrol.StartListening ``` ## Remarks This method begins listening for incoming connections on the port specified by LocalPort. Once listening, events will fire as new clients connect and data are transferred. To stop listening for new connections, call [StopListening](#stoplistening-method-mqttbroker-control). To stop listening for new connections and to disconnect all existing clients, call [Shutdown](#shutdown-method-mqttbroker-control). # StopListening Method ([MQTTBroker](#mqttbroker-control) Control) This method stops listening for new connections. ## Syntax ```text mqttbrokercontrol.StopListening ``` ## Remarks This method stops listening for new connections. After being called, any new connection attempts will be rejected. Calling this method does not disconnect existing connections. To stop listening and to disconnect all existing clients, call [Shutdown](#shutdown-method-mqttbroker-control) instead. # Connected Event ([MQTTBroker](#mqttbroker-control) Control) This event is fired immediately after a connection completes (or fails). ## Syntax ```text Sub mqttbrokercontrol_Connected(ConnectionId As Integer, StatusCode As Integer, Description As String) ``` ## Remarks If the connection is made normally, *StatusCode* is 0, and *Description* is "OK". If the connection fails, *StatusCode* has the error code returned by the system. *Description* contains a description of this code. The value of *StatusCode* is equal to the value of the system error. The corresponding Visual Basic error code can be obtained by adding 15001 to this value. Please refer to the [Error Codes](#trappable-errors-mqttbroker-control) section for more information. # ConnectionRequest Event ([MQTTBroker](#mqttbroker-control) Control) This event is fired when a request for connection comes from a remote host. ## Syntax ```text Sub mqttbrokercontrol_ConnectionRequest(Address As String, Port As Integer, Accept As Boolean) ``` ## Remarks This event indicates an incoming connection. The connection is accepted by default. *Address* and *Port* will contain information about the remote host requesting the inbound connection. If you want to refuse it, you can set the *Accept* parameter to False. # Disconnected Event ([MQTTBroker](#mqttbroker-control) Control) This event is fired when a connection is closed. ## Syntax ```text Sub mqttbrokercontrol_Disconnected(ConnectionId As Integer, StatusCode As Integer, Description As String) ``` ## Remarks If the connection is broken normally, *StatusCode* is 0, and *Description* is "OK". If the connection is broken for any other reason, *StatusCode* has the error code returned by the system. *Description* contains a description of this code. The value of *StatusCode* is equal to the value of the system error. The corresponding Visual Basic error code can be obtained by adding 15001 to this value. Please refer to the [Error Codes](#trappable-errors-mqttbroker-control) section for more information. # Error Event ([MQTTBroker](#mqttbroker-control) Control) This event fires information about errors during data delivery. ## Syntax ```text Sub mqttbrokercontrol_Error(ConnectionId As Integer, ErrorCode As Integer, Description As String) ``` ## Remarks The Error event is fired in case of exceptional conditions during message processing. Normally, the control fails with an error. *ErrorCode* contains an error code and *Description* contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the [Error Codes](#trappable-errors-mqttbroker-control) section. *ConnectionId* indicates the connection for which the error is applicable. # IncomingMessageStatus Event ([MQTTBroker](#mqttbroker-control) Control) Fires when an incoming message's state is updated. ## Syntax ```text Sub mqttbrokercontrol_IncomingMessageStatus(ConnectionId As Integer, ClientId As String, MessageId As Long64, DUP As Boolean, QoS As Integer, Retain As Boolean, PacketId As Integer, State As Integer) ``` ## Remarks The *IncomingMessageStatus* event fires each time an incoming message's state is updated. - MessageId: A unique identifier for this message. - DUP: Whether or not the server has indicated that this message is a duplicate of another message received previously. - QoS: The message's QoS level. - Retain: Whether or not this message was received as a result of subscribing to a topic. - PacketId: The message packet Id. This will always be -1 if QoS is 0. - State: Information about the incoming message's state. - 6 - For an incoming QoS 1 message, which has been received from the client, but prior to sending the PUBACK for it. When the PUBACK is sent, the state will change to 10. - 7 - For an incoming QoS 2 message, which has been received from a client, but prior to sending the PUBREC for it, - 8 - For an incoming QoS 2 message, which has sent the PUBREC, but waiting to receive the PUBREL for it. - 9 - For an incoming QoS 2 message, which has received the PUBREL, but prior to sending the PUBCOMP for it. When the PUBCOMP is sent, the state will change to 10. - 10 - Message successfully received. # Log Event ([MQTTBroker](#mqttbroker-control) Control) Fires once for each log message. ## Syntax ```text Sub mqttbrokercontrol_Log(ConnectionId As Integer, LogLevel As Integer, Message As String, LogType As String) ``` ## Remarks This event fires once for each log message generated by the control. The verbosity is controlled by the [LogLevel](#LogLevel) setting. *LogLevel* indicates the level of the *Message*. Possible values are: | | | | --- | --- | | 0 (None) | No events are logged. | | 1 (Info - default) | Informational events are logged. | | 2 (Verbose) | Detailed data is logged. | | 3 (Debug) | Debug data is logged. | *LogType* identifies the type of log entry. Possible values are: - Info: General information about the control. - Session: Session status messages. - Frame: Frame status messages. # MessageReceived Event ([MQTTBroker](#mqttbroker-control) Control) Fires when a new message is received from a client. ## Syntax ```text Sub mqttbrokercontrol_MessageReceived(ConnectionId As Integer, ClientId As String, MessageId As Long64) ``` ## Remarks This event fires each time a message is received from a client. # MessageReceiving Event ([MQTTBroker](#mqttbroker-control) Control) Fires when a message is initially received from a client. ## Syntax ```text Sub mqttbrokercontrol_MessageReceiving(ConnectionId As Integer, ClientId As String, MessageId As Long64, DUP As Boolean, QoS As Integer, Retain As Boolean, PacketId As Integer) ``` ## Remarks The MessageReceiving event fires once for each incoming message immediately after it is received from a client. - MessageId: A unique identifier for this message. - DUP: Whether or not the server has indicated that this message is a duplicate of another message sent previously. - QoS: The message's QoS level. - Retain: Whether or not this message was received as a result of subscribing to a topic. - PacketId: The message packet Id. This will always be -1 if QoS is 0. # MessageSending Event ([MQTTBroker](#mqttbroker-control) Control) Fires when a message is initially sent to a client. ## Syntax ```text Sub mqttbrokercontrol_MessageSending(ConnectionId As Integer, ClientId As String, MessageId As Long64, DUP As Boolean, QoS As Integer, Retain As Boolean, PacketId As Integer) ``` ## Remarks The MessageSending fires once for each outgoing message immediately after it is sent to a client. - MessageId: A unique identifier for this message. - DUP: Whether or not the server has indicated that this message is a duplicate of another message sent previously. - QoS: The message's QoS level. - Retain: Whether or not this message was received as a result of subscribing to a topic. - PacketId: The message packet Id. This will always be -1 if QoS is 0. # MessageSent Event ([MQTTBroker](#mqttbroker-control) Control) Fires after a message is successfully delivered to a client, confirming transmission. ## Syntax ```text Sub mqttbrokercontrol_MessageSent(ConnectionId As Integer, ClientId As String, MessageId As Long64) ``` ## Remarks This event fires each time a message is delivered to a client. # OutgoingMessageStatus Event ([MQTTBroker](#mqttbroker-control) Control) Fired to provide the current delivery status of an outgoing message. Includes success or failure metadata. ## Syntax ```text Sub mqttbrokercontrol_OutgoingMessageStatus(ConnectionId As Integer, ClientId As String, MessageId As Long64, DUP As Boolean, QoS As Integer, Retain As Boolean, PacketId As Integer, State As Integer) ``` ## Remarks The *OutgoingMessageStatus* event fires each time an outgoing message's state is updated. - MessageId: A unique identifier for this message. - DUP: Whether or not the server has indicated that this message is a duplicate of another message sent previously. - QoS: The message's QoS level. - Retain: Whether or not this message is a retained message. - PacketId: The message packet Id. This will always be -1 if QoS is 0. - State: Information about the outgoing message's state. - 1 - Outgoing message is waiting to be sent - 2 - For an outgoing QoS 1 message, which has been sent to the client and waiting for the PUBACK. When the PUBACK is received, the state will change to 10. - 3 - For an outgoing QoS 2 message, which has been sent to the client and waiting for the PUBREC. - 4 - For an outgoing QoS 2 message, which has received the PUBREC, prior to sending the PUBREL for it. - 5 - For an outgoing QoS 2 message, which has sent the PUBREL. When the PUBCOMP is received, the state will change to 10. - 10 - Message successfully sent. # SessionRemoved Event ([MQTTBroker](#mqttbroker-control) Control) Fired when a client session is removed, indicating all resources associated with the session are cleaned up. ## Syntax ```text Sub mqttbrokercontrol_SessionRemoved(ClientId As String) ``` ## Remarks The client with the associated *ClientId* will also be removed from the Sessions collection when this event returns. # SessionRequest Event ([MQTTBroker](#mqttbroker-control) Control) Fires when a new session is requested. ## Syntax ```text Sub mqttbrokercontrol_SessionRequest(ConnectionId As Integer, ClientId As String, UserName As String, Password As String, IsNew As Boolean, Accept As Boolean) ``` ## Remarks *UserName* and *Password* contain authentication credentials which can be verified in this event. *IsNew* denotes whether this is a clean session from the client. *Accept* can be set to false to reject the client. Set *Accept* to true to accept this client. **Example:** ```csharp broker.OnSessionRequest += (s,e) => { // Check e.UserName and e.Password if needed // Set Accept to true to accept the session request e.Accept = true; }; ``` # SSLClientAuthentication Event ([MQTTBroker](#mqttbroker-control) Control) This event is fired when the client presents its credentials to the server. ## Syntax ```text Sub mqttbrokercontrol_SSLClientAuthentication(ConnectionId As Integer, CertEncoded As String, CertSubject As String, CertIssuer As String, Status As String, Accept As Boolean) ``` ## Remarks This event enables the server to decide whether or not to continue. The *Accept* parameter is a recommendation on whether to continue or to close the connection. This is just a suggestion: application software must use its own logic to determine whether or not to continue. When *Accept* is False, *Status* shows why the verification failed (otherwise, *Status* contains the string "OK"). # SSLStatus Event ([MQTTBroker](#mqttbroker-control) Control) This event is fired to show the progress of the secure connection. ## Syntax ```text Sub mqttbrokercontrol_SSLStatus(ConnectionId As Integer, Message As String) ``` ## Remarks The event is fired for informational and logging purposes only. It is used to track the progress of the connection. # Subscribe Event ([MQTTBroker](#mqttbroker-control) Control) Fires when a client requests to subscribe to a topic. ## Syntax ```text Sub mqttbrokercontrol_Subscribe(ConnectionId As Integer, ClientId As String, TopicFilter As String, RequestedQoS As Integer, ReturnCode As Integer) ``` ## Remarks The *ClientId* is used to identify this client in subsequent actions. The *TopicFilter* is the requested topic the client wishes to subscribe to. The *RequestedQoS* is the client's preferred QoS level. *ReturnCode* is used to confirm the maximum QoS level granted for this subscription or indicate a failure. This can be less than the client's *RequestedQoS*. | | | | --- | --- | | 0x00 | Success - Maximum QoS 0 | | 0x01 | Success - Maximum QoS 1 | | 0x02 | Success - Maximum QoS 2 | | 0x80 | Failure | # Unsubscribe Event ([MQTTBroker](#mqttbroker-control) Control) Fires when a client unsubscribes from a topic, removing its subscription data. ## Syntax ```text Sub mqttbrokercontrol_Unsubscribe(ConnectionId As Integer, ClientId As String, TopicFilter As String) ``` ## Remarks The *TopicFilter* shows the topic this client is unsubscribing from. # Config Settings ([MQTTBroker](#mqttbroker-control) Control) The control accepts one or more of the following *configuration settings*. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the control, access to these *internal properties* is provided through the [Config](#config-method-mqttbroker-control) method. ### TCPClient Config Settings **ConnectionTimeout**: Sets a separate timeout value for establishing a connection.When set, this configuration setting allows you to specify a different timeout value for establishing a connection. Otherwise, the control will use Timeout for establishing a connection and transmitting/receiving data. **EnableFallback**: Whether to try the other addresses the remote host resolves to when a connection attempt fails.When set to True and RemoteHost resolves to more than one address, the control will try the remaining addresses in turn if the connection to the first one fails, and only fails with an error once every address has been tried. The error reported is the one from the last attempt. Use [FallbackTimeout](#FallbackTimeout) to limit the total time spent. NOTE: Only addresses of the same IP version as the first one are tried, this setting does not fall back from IPv6 to IPv4. Selecting between IPv6 and IPv4 is done by [UseIPv6](#UseIPv6) when the host is resolved. This setting must be set before the connection is established. The default value for this setting is False. **FallbackTimeout**: The maximum time in milliseconds to spend on connection attempts when EnableFallback is enabled.This setting limits the total time that the control will spend on all of the connection attempts made when [EnableFallback](#EnableFallback) is enabled. The default value is 0, in which case each attempt uses the operating system's own connection timeout. NOTE: This setting only applies when [EnableFallback](#EnableFallback) is True. It is unrelated to [ConnectionTimeout](#ConnectionTimeout), which is specified in seconds and applies to the Connected operation as a whole. **FirewallAutoDetect**: Tells the control whether or not to automatically detect and use firewall system settings, if available.This configuration setting is provided for use by controls that do not directly expose Firewall properties. **FirewallHost**: Name or IP address of firewall (optional).If a [FirewallHost](#FirewallHost) is given, requested connections will be authenticated through the specified firewall when connecting. If the [FirewallHost](#FirewallHost) setting is set to a Domain Name, a DNS request is initiated. Upon successful termination of the request, the [FirewallHost](#FirewallHost) setting is set to the corresponding address. If the search is not successful, an error is returned. NOTE: This setting is provided for use by controls that do not directly expose Firewall properties. **FirewallHTTPVersion**: The HTTP version to be used when connecting through a tunneling proxy.When [FirewallType](#FirewallType) is set to a tunneling proxy, this setting dictates which HTTP version is used when connecting. **FirewallPassword**: Password to be used if authentication is to be used when connecting through the firewall.If [FirewallHost](#FirewallHost) is specified, the [FirewallUser](#FirewallUser) and [FirewallPassword](#FirewallPassword) settings are used to connect and authenticate to the given firewall. If the authentication fails, the control fails with an error. NOTE: This setting is provided for use by controls that do not directly expose Firewall properties. **FirewallPort**: The TCP port for the FirewallHost;.The [FirewallPort](#FirewallPort) is set automatically when [FirewallType](#FirewallType) is set to a valid value. NOTE: This configuration setting is provided for use by controls that do not directly expose Firewall properties. **FirewallType**: Determines the type of firewall to connect through.Possible values are as follows: | | | | --- | --- | | 0 | No firewall (default setting). | | 1 | Connect through a tunneling proxy. [FirewallPort](#FirewallPort) is set to 80. | | 2 | Connect through a SOCKS4 Proxy. [FirewallPort](#FirewallPort) is set to 1080. | | 3 | Connect through a SOCKS5 Proxy. [FirewallPort](#FirewallPort) is set to 1080. | | 10 | Connect through a SOCKS4A Proxy. [FirewallPort](#FirewallPort) is set to 1080. | NOTE: This setting is provided for use by controls that do not directly expose Firewall properties. **FirewallUser**: A user name if authentication is to be used connecting through a firewall.If the [FirewallHost](#FirewallHost) is specified, the [FirewallUser](#FirewallUser) and [FirewallPassword](#FirewallPassword) settings are used to connect and authenticate to the Firewall. If the authentication fails, the control fails with an error. NOTE: This setting is provided for use by controls that do not directly expose Firewall properties. **KeepAliveInterval**: The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.When set, [TCPKeepAlive](#TCPKeepAlive) will automatically be set to True. A TCP keep-alive packet will be sent after a period of inactivity as defined by [KeepAliveTime](#KeepAliveTime). If no acknowledgment is received from the remote host, the keep-alive packet will be sent again. This configuration setting specifies the interval at which the successive keep-alive packets are sent in milliseconds. This system default if this value is not specified here is 1 second. NOTE: This value is not applicable in macOS. **KeepAliveTime**: The inactivity time in milliseconds before a TCP keep-alive packet is sent.When set, [TCPKeepAlive](#TCPKeepAlive) will automatically be set to True. By default, the operating system will determine the time a connection is idle before a Transmission Control Protocol (TCP) keep-alive packet is sent. This system default if this value is not specified here is 2 hours. In many cases, a shorter interval is more useful. Set this value to the desired interval in milliseconds. **Linger**: When set to True, connections are terminated gracefully.This property controls how a connection is closed. The default is True. In the case that Linger is True (default), two scenarios determine how long the connection will linger. In the first, if [LingerTime](#LingerTime) is 0 (default), the system will attempt to send pending data for a connection until the default IP timeout expires. In the second scenario, if [LingerTime](#LingerTime) is a positive value, the system will attempt to send pending data until the specified [LingerTime](#LingerTime) is reached. If this attempt fails, then the system will reset the connection. The default behavior (which is also the default mode for stream sockets) might result in a long delay in closing the connection. Although the control returns control immediately, the system could hold system resources until all pending data are sent (even after your application closes). Setting this property to False forces an immediate disconnection. If you know that the other side has received all the data you sent (e.g., by a client acknowledgment), setting this property to False might be the appropriate course of action. **LingerTime**: Time in seconds to have the connection linger. LingerTime is the time, in seconds, the socket connection will linger. This value is 0 by default, which means it will use the default IP timeout. **LocalHost**: The name of the local host through which connections are initiated or accepted. The LocalHost setting contains the name of the local host as obtained by the *gethostname()* system call, or if the user has assigned an IP address, the value of that address. In multihomed hosts (machines with more than one IP interface), setting LocalHost to the value of an interface will make the control initiate connections (or accept in the case of server controls) only through that interface. If the control is connected, the LocalHost setting shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multihomed hosts (machines with more than one IP interface). **LocalPort**: The port in the local host where the control binds. This configuration setting must be set before a connection is attempted. It instructs the control to bind to a specific port (or communication endpoint) in the local machine. Setting this to 0 (default) enables the system to choose a port at random. The chosen port will be shown by LocalPort after the connection is established. LocalPort cannot be changed once a connection is made. Any attempt to set this when a connection is active will generate an error. This configuration setting is useful when trying to connect to services that require a trusted port on the client side. An example is the remote shell (rsh) service in UNIX systems. **MaxLineLength**: The maximum amount of data to accumulate when no EOL is found.[MaxLineLength](#MaxLineLength) is the size of an internal buffer, which holds received data while waiting for an EOL string. If an EOL string is found in the input stream before [MaxLineLength](#MaxLineLength) bytes are received, the DataIn event is fired with the *EOL* parameter set to True, and the buffer is reset. If no EOL is found, and [MaxLineLength](#MaxLineLength) bytes are accumulated in the buffer, the DataIn event is fired with the *EOL* parameter set to False, and the buffer is reset. The minimum value for [MaxLineLength](#MaxLineLength) is 256 bytes. The default value is 2048 bytes. **MaxTransferRate**: The transfer rate limit in bytes per second.This configuration setting can be used to throttle outbound TCP traffic. Set this to the number of bytes to be sent per second. By default, this is not set and there is no limit. **ProxyExceptionsList**: A semicolon separated list of hosts and IPs to bypass when using a proxy.This configuration setting optionally specifies a semicolon-separated list of hostnames or IP addresses to bypass when a proxy is in use. When requests are made to hosts specified in this property, the proxy will not be used. For instance: *www.google.com;www.example.com* **TCPKeepAlive**: Determines whether or not the keep alive socket option is enabled.If set to True, the socket's keep-alive option is enabled and keep-alive packets will be sent periodically to maintain the connection. Set [KeepAliveTime](#KeepAliveTime) and [KeepAliveInterval](#KeepAliveInterval) to configure the timing of the keep-alive packets. NOTE: This value is not applicable in Java. **TcpNoDelay**: Whether or not to delay when sending packets. When set to True, the socket will send all data that are ready to send at once. When set to False, the socket will send smaller buffered packets of data at small intervals. This is known as the Nagle algorithm. By default, this configuration setting is set to False. **UseIPv6**: Whether to use IPv6.When set to *0* (default), the control will use IPv4 exclusively. When set to *1*, the control will use IPv6 exclusively. To instruct the control to prefer IPv6 addresses, but use IPv4 if IPv6 is not supported on the system, this setting should be set to *2*. The default value is *0*. Possible values are as follows: | | | | --- | --- | | 0 | IPv4 only | | 1 | IPv6 only | | 2 | IPv6 with IPv4 fallback | **UseNTLMv2**: Whether to use NTLM V2.When authenticating with NTLM, this setting specifies whether NTLM V2 is used. By default this value is True and NTLM V2 will be used. Set this to False to use NTLM V1. ### SSL Config Settings **LogSSLPackets**: Controls whether SSL packets are logged when using the internal security API.When [SSLProvider](#sslprovider-property-mqttbroker-control) is set to *Internal*, this configuration setting controls whether Secure Sockets Layer (SSL) packets should be logged. By default, this configuration setting is *False*, as it is useful only for debugging purposes. When enabled, SSL packet logs are output using the [SSLStatus](#sslstatus-event-mqttbroker-control) event, which will fire each time an SSL packet is sent or received. Enabling this configuration setting has no effect if [SSLProvider](#sslprovider-property-mqttbroker-control) is set to *Platform*. **OpenSSLCADir**: The path to a directory containing CA certificates.This functionality is available only when the provider is OpenSSL. The path set by this property should point to a directory containing CA certificates in PEM format. The files each contain one CA certificate. The files are looked up by the CA subject name hash value, which must hence be available. If more than one CA certificate with the same name hash value exist, the extension must be different (e.g., 9d66eef0.0, 9d66eef0.1). OpenSSL recommends the use of the c_rehash utility to create the necessary links. Please refer to the OpenSSL man page SSL_CTX_load_verify_locations(3) for details. **OpenSSLCAFile**: Name of the file containing the list of CA's trusted by your application.This functionality is available only when the provider is OpenSSL. The file set by this property should contain a list of CA certificates in PEM format. The file can contain several CA certificates identified by the following sequences: -----BEGIN CERTIFICATE----- ... (CA certificate in base64 encoding) ... -----END CERTIFICATE----- Before, between, and after the certificate text is allowed, which can be used, for example, for descriptions of the certificates. Refer to the OpenSSL man page SSL_CTX_load_verify_locations(3) for details. **OpenSSLCipherList**: A string that controls the ciphers to be used by SSL.This functionality is available only when the provider is OpenSSL. The format of this string is described in the OpenSSL man page ciphers(1) section "CIPHER LIST FORMAT". Please refer to it for details. The default string "DEFAULT" is determined at compile time and is normally equivalent to "ALL:!ADH:RC4+RSA:+SSLv2:@STRENGTH". **OpenSSLPrngSeedData**: The data to seed the pseudo random number generator (PRNG).This functionality is available only when the provider is OpenSSL. By default, OpenSSL uses the device file "/dev/urandom" to seed the PRNG, and setting OpenSSLPrngSeedData is not required. If set, the string specified is used to seed the PRNG. **ReuseSSLSession**: Determines if the SSL session is reused. If set to True, the control will reuse the context if and only if the following criteria are met: - The target host name is the same. - The system cache entry has not expired (default timeout is 10 hours). - The application process that calls the function is the same. - The logon session is the same. - The instance of the control is the same. **SSLCACerts**: A newline separated list of CA certificates to be included when performing an SSL handshake.When [SSLProvider](#sslprovider-property-mqttbroker-control) is set to *Internal*, this configuration setting specifies one or more CA certificates to be included with the SSLCert property. Some servers or clients require the entire chain, including CA certificates, to be presented when performing SSL authentication. The value of this configuration setting is a newline-separated (CR/LF) list of certificates. For instance: ```text -----BEGIN CERTIFICATE----- MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw ... Intermediate Cert ... eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w F0I1XhM+pKj7FjDr+XNj -----END CERTIFICATE----- \r \n -----BEGIN CERTIFICATE----- MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp ... Root Cert ... d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA -----END CERTIFICATE----- ``` **SSLCheckCRL**: Whether to check the Certificate Revocation List for the server certificate.This configuration setting specifies whether the control will check the Certificate Revocation List (CRL) specified by the server certificate. If set to 1 or 2, the control will first obtain the list of CRL URLs from the server certificate's CRL distribution points extension. The control will then make HTTP requests to each CRL endpoint to check the validity of the server's certificate. If the certificate has been revoked or any other issues are found during validation the control fails with an error. When set to 0 (default), the CRL check will not be performed by the control. When set to 1, it will attempt to perform the CRL check, but it will continue without an error if the server's certificate does not support CRL. When set to 2, it will perform the CRL check and will throw an error if CRL is not supported. This configuration setting is supported only in the Java, C#, and C++ editions. In the C++ edition, it is supported only on Windows operating systems. **SSLCheckOCSP**: Whether to use OCSP to check the status of the server certificate.This configuration setting specifies whether the control will use OCSP to check the validity of the server certificate. If set to 1 or 2, the control will first obtain the Online Certificate Status Protocol (OCSP) URL from the server certificate's OCSP extension. The control will then locate the issuing certificate and make an HTTP request to the OCSP endpoint to check the validity of the server's certificate. If the certificate has been revoked or any other issues are found during validation, the control fails with an error. When set to 0 (default), the control will not perform an OCSP check. When set to 1, it will attempt to perform the OCSP check, but it will continue without an error if the server's certificate does not support OCSP. When set to 2, it will perform the OCSP check and will throw an error if OCSP is not supported. This configuration setting is supported only in the Java, C#, and C++ editions. In the C++ edition, it is supported only on Windows operating systems. **SSLCipherStrength**: The minimum cipher strength used for bulk encryption. This minimum cipher strength is largely dependent on the security modules installed on the system. If the cipher strength specified is not supported, an error will be returned when connections are initiated. NOTE: This configuration setting contains the minimum cipher strength requested from the security library. The actual cipher strength used for the connection is shown by the [SSLStatus](#sslstatus-event-mqttbroker-control) event. Use this configuration setting with caution. Requesting a lower cipher strength than necessary could potentially cause serious security vulnerabilities in your application. When the provider is OpenSSL, [SSLCipherStrength](#SSLCipherStrength) is currently not supported. This functionality is instead made available through the [OpenSSLCipherList](#OpenSSLCipherList) configuration setting. **SSLClientCACerts**: A newline separated list of CA certificates to use during SSL client certificate validation.This configuration setting is only applicable to server components (e.g., TCPServer) see [SSLServerCACerts](#SSLServerCACerts) for client components (e.g., TCPClient). This setting can be used to optionally specify one or more CA certificates to be used when verifying the client certificate that is presented by the client during the SSL handshake when SSLAuthenticateClients is enabled. When verifying the client's certificate, the certificates trusted by the system will be used as part of the verification process. If the client's CA certificates are not installed to the trusted system store, they may be specified here so they are included when performing the verification process. This configuration setting should be set only if the client's CA certificates are not already trusted on the system and cannot be installed to the trusted system store. The value of this configuration setting is a newline-separated (CR/LF) list of certificates. For instance: ```text -----BEGIN CERTIFICATE----- MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw ... Intermediate Cert ... eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w F0I1XhM+pKj7FjDr+XNj -----END CERTIFICATE----- \r \n -----BEGIN CERTIFICATE----- MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp ... Root Cert ... d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA -----END CERTIFICATE----- ``` **SSLEnabledCipherSuites**: The cipher suite to be used in an SSL negotiation.This configuration setting enables the cipher suites to be used in SSL negotiation. By default, the enabled cipher suites will include all available ciphers ("*"). The special value "*" means that the control will pick all of the supported cipher suites. If [SSLEnabledCipherSuites](#SSLEnabledCipherSuites) is set to any other value, only the specified cipher suites will be considered. Multiple cipher suites are separated by semicolons. Example values when [SSLProvider](#sslprovider-property-mqttbroker-control) is set to *Platform* include the following: ```text obj.config("SSLEnabledCipherSuites=*"); obj.config("SSLEnabledCipherSuites=CALG_AES_256"); obj.config("SSLEnabledCipherSuites=CALG_AES_256;CALG_3DES"); ``` Possible values when [SSLProvider](#sslprovider-property-mqttbroker-control) is set to *Platform* include the following: - CALG_3DES - CALG_3DES_112 - CALG_AES - CALG_AES_128 - CALG_AES_192 - CALG_AES_256 - CALG_AGREEDKEY_ANY - CALG_CYLINK_MEK - CALG_DES - CALG_DESX - CALG_DH_EPHEM - CALG_DH_SF - CALG_DSS_SIGN - CALG_ECDH - CALG_ECDH_EPHEM - CALG_ECDSA - CALG_ECMQV - CALG_HASH_REPLACE_OWF - CALG_HUGHES_MD5 - CALG_HMAC - CALG_KEA_KEYX - CALG_MAC - CALG_MD2 - CALG_MD4 - CALG_MD5 - CALG_NO_SIGN - CALG_OID_INFO_CNG_ONLY - CALG_OID_INFO_PARAMETERS - CALG_PCT1_MASTER - CALG_RC2 - CALG_RC4 - CALG_RC5 - CALG_RSA_KEYX - CALG_RSA_SIGN - CALG_SCHANNEL_ENC_KEY - CALG_SCHANNEL_MAC_KEY - CALG_SCHANNEL_MASTER_HASH - CALG_SEAL - CALG_SHA - CALG_SHA1 - CALG_SHA_256 - CALG_SHA_384 - CALG_SHA_512 - CALG_SKIPJACK - CALG_SSL2_MASTER - CALG_SSL3_MASTER - CALG_SSL3_SHAMD5 - CALG_TEK - CALG_TLS1_MASTER - CALG_TLS1PRF Example values when [SSLProvider](#sslprovider-property-mqttbroker-control) is set to *Internal*include the following: ```text obj.config("SSLEnabledCipherSuites=*"); obj.config("SSLEnabledCipherSuites=TLS_DHE_DSS_WITH_AES_128_CBC_SHA"); obj.config("SSLEnabledCipherSuites=TLS_DHE_DSS_WITH_AES_128_CBC_SHA;TLS_ECDH_RSA_WITH_AES_128_CBC_SHA"); ``` Possible values when [SSLProvider](#sslprovider-property-mqttbroker-control) is set to *Internal* include the following: - TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 - TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 - TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 - TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 - TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 - TLS_RSA_WITH_AES_256_GCM_SHA384 - TLS_RSA_WITH_AES_128_GCM_SHA256 - TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 - TLS_DHE_DSS_WITH_AES_256_GCM_SHA384 - TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 - TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 - TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 - TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 - TLS_DHE_DSS_WITH_AES_128_GCM_SHA256 - TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 - TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 - TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 - TLS_DHE_DSS_WITH_AES_256_CBC_SHA256 - TLS_RSA_WITH_AES_256_CBC_SHA256 - TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 - TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 - TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 - TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 - TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 - TLS_RSA_WITH_AES_128_CBC_SHA256 - TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 - TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 - TLS_DHE_DSS_WITH_AES_128_CBC_SHA256 - TLS_RSA_WITH_AES_256_CBC_SHA - TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA - TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA - TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA - TLS_DHE_RSA_WITH_AES_256_CBC_SHA - TLS_ECDH_RSA_WITH_AES_256_CBC_SHA - TLS_DHE_DSS_WITH_AES_256_CBC_SHA - TLS_RSA_WITH_AES_128_CBC_SHA - TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA - TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA - TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA - TLS_ECDH_RSA_WITH_AES_128_CBC_SHA - TLS_DHE_RSA_WITH_AES_128_CBC_SHA - TLS_DHE_DSS_WITH_AES_128_CBC_SHA - TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA - TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA - TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA - TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA - TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA - TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA - TLS_RSA_WITH_3DES_EDE_CBC_SHA - TLS_RSA_WITH_DES_CBC_SHA - TLS_DHE_RSA_WITH_DES_CBC_SHA - TLS_DHE_DSS_WITH_DES_CBC_SHA - TLS_RSA_WITH_RC4_128_MD5 - TLS_RSA_WITH_RC4_128_SHA When TLS 1.3 is negotiated (see [SSLEnabledProtocols](#SSLEnabledProtocols)), only the following cipher suites are supported: - TLS_AES_256_GCM_SHA384 - TLS_CHACHA20_POLY1305_SHA256 - TLS_AES_128_GCM_SHA256 [SSLEnabledCipherSuites](#SSLEnabledCipherSuites) is used together with [SSLCipherStrength](#SSLCipherStrength). **SSLEnabledProtocols**: Used to enable/disable the supported security protocols.This configuration setting is used to enable or disable the supported security protocols. Not all supported protocols are enabled by default. The default value is *4032* for client components, and *3072* for server components. To specify a combination of enabled protocol versions set this config to the binary *OR* of one or more of the following values: | | | | --- | --- | | TLS1.3 | 12288 (Hex 3000) | | TLS1.2 | 3072 (Hex C00) (Default - Client and Server) | | TLS1.1 | 768 (Hex 300) (Default - Client) | | TLS1 | 192 (Hex C0) (Default - Client) | | SSL3 | 48 (Hex 30) | | SSL2 | 12 (Hex 0C) | Note that only TLS 1.2 is enabled for server components that accept incoming connections. This adheres to industry standards to ensure a secure connection. Client components enable TLS 1.0, TLS 1.1, and TLS 1.2 by default and will negotiate the highest mutually supported version when connecting to a server, which should be TLS 1.2 in most cases. **SSLEnabledProtocols: Transport Layer Security (TLS) 1.3 Notes:** By default when TLS 1.3 is enabled, the control will first try to use the platform TLS 1.3 implementation when the [SSLProvider](#sslprovider-property-mqttbroker-control) is set to Automatic for all editions. If the platform TLS 1.3 implementation is not available, the internal implementation will be used. In editions that are designed to run on Windows, [SSLProvider](#sslprovider-property-mqttbroker-control) can be set to Platform to use the platform implementation instead of the internal implementation. When configured in this manner, please note that the platform provider is supported only on Windows 11/Windows Server 2022 and up. The default internal provider is available on all platforms and is not restricted to any specific OS version. If set to *1* (Platform provider), please be aware of the following notes: - The platform provider is available only on Windows 11/Windows Server 2022 and up. - [SSLEnabledCipherSuites](#SSLEnabledCipherSuites) and other similar SSL configuration settings are not supported. - If [SSLEnabledProtocols](#SSLEnabledProtocols) includes both TLS 1.3 and TLS 1.2, these restrictions are still applicable even if TLS 1.2 is negotiated. Enabling TLS 1.3 with the platform provider changes the implementation used for all TLS versions. **SSLEnabledProtocols: SSL2 and SSL3 Notes: ** SSL 2.0 and 3.0 are not supported by the control when the [SSLProvider](#sslprovider-property-mqttbroker-control) is set to internal. To use SSL 2.0 or SSL 3.0, the platform security API must have the protocols enabled and [SSLProvider](#sslprovider-property-mqttbroker-control) needs to be set to platform. **SSLEnableRenegotiation**: Whether the renegotiation_info SSL extension is supported.This configuration setting specifies whether the renegotiation_info SSL extension will be used in the request when using the internal security API. This configuration setting is *False* by default, but it can be set to *True* to enable the extension. This configuration setting is applicable only when [SSLProvider](#sslprovider-property-mqttbroker-control) is set to *Internal*. **SSLIncludeCertChain**: Whether the entire certificate chain is included in the SSLServerAuthentication event.This configuration setting specifies whether the Encoded parameter of the SSLServerAuthentication event contains the full certificate chain. By default this value is False and only the leaf certificate will be present in the Encoded parameter of the SSLServerAuthentication event. If set to True, all certificates returned by the server will be present in the Encoded parameter of the SSLServerAuthentication event. This includes the leaf certificate, any intermediate certificate, and the root certificate. **SSLKeyLogFile**: The location of a file where per-session secrets are written for debugging purposes.This configuration setting optionally specifies the full path to a file on disk where per-session secrets are stored for debugging purposes. When set, the control will save the session secrets in the same format as the SSLKEYLOGFILE environment variable functionality used by most major browsers and tools, such as Chrome, Firefox, and cURL. This file can then be used in tools such as Wireshark to decrypt TLS traffic for debugging purposes. When writing to this file, the control will only append, it will not overwrite previous values. NOTE: This configuration setting is applicable only when [SSLProvider](#sslprovider-property-mqttbroker-control) is set to *Internal*. **SSLNegotiatedCipher**: Returns the negotiated cipher suite.This configuration setting returns the cipher suite negotiated during the SSL handshake. NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: ```csharp server.Config("SSLNegotiatedCipher[connId]"); ``` **SSLNegotiatedCipherStrength**: Returns the negotiated cipher suite strength.This configuration setting returns the strength of the cipher suite negotiated during the SSL handshake. NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: ```csharp server.Config("SSLNegotiatedCipherStrength[connId]"); ``` **SSLNegotiatedCipherSuite**: Returns the negotiated cipher suite.This configuration setting returns the cipher suite negotiated during the SSL handshake represented as a single string. NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: ```csharp server.Config("SSLNegotiatedCipherSuite[connId]"); ``` **SSLNegotiatedKeyExchange**: Returns the negotiated key exchange algorithm.This configuration setting returns the key exchange algorithm negotiated during the SSL handshake. NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: ```csharp server.Config("SSLNegotiatedKeyExchange[connId]"); ``` **SSLNegotiatedKeyExchangeStrength**: Returns the negotiated key exchange algorithm strength.This configuration setting returns the strength of the key exchange algorithm negotiated during the SSL handshake. NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: ```csharp server.Config("SSLNegotiatedKeyExchangeStrength[connId]"); ``` **SSLNegotiatedVersion**: Returns the negotiated protocol version.This configuration setting returns the protocol version negotiated during the SSL handshake. NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: ```csharp server.Config("SSLNegotiatedVersion[connId]"); ``` **SSLSecurityFlags**: Flags that control certificate verification.The following flags are defined (specified in hexadecimal notation). They can be ORed together to exclude multiple conditions: | | | | --- | --- | | 0x00000001 | Ignore time validity status of certificate. | | 0x00000002 | Ignore time validity status of CTL. | | 0x00000004 | Ignore non-nested certificate times. | | 0x00000010 | Allow unknown certificate authority. | | 0x00000020 | Ignore wrong certificate usage. | | 0x00000100 | Ignore unknown certificate revocation status. | | 0x00000200 | Ignore unknown CTL signer revocation status. | | 0x00000400 | Ignore unknown certificate authority revocation status. | | 0x00000800 | Ignore unknown root revocation status. | | 0x00008000 | Allow test root certificate. | | 0x00004000 | Trust test root certificate. | | 0x80000000 | Ignore non-matching CN (certificate CN non-matching server name). | This functionality is currently not available when the provider is OpenSSL. **SSLServerCACerts**: A newline separated list of CA certificates to use during SSL server certificate validation.This configuration setting is only used by client components (e.g., TCPClient) see [SSLClientCACerts](#SSLClientCACerts) for server components (e.g., TCPServer). This configuration setting can be used to optionally specify one or more CA certificates to be used when connecting to the server and verifying the server certificate. When verifying the server's certificate, the certificates trusted by the system will be used as part of the verification process. If the server's CA certificates are not installed to the trusted system store, they may be specified here so they are included when performing the verification process. This configuration setting should be set only if the server's CA certificates are not already trusted on the system and cannot be installed to the trusted system store. The value of this configuration setting is a newline-separated (CR/LF) list of certificates. For instance: ```text -----BEGIN CERTIFICATE----- MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw ... Intermediate Cert... eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w F0I1XhM+pKj7FjDr+XNj -----END CERTIFICATE----- \r \n -----BEGIN CERTIFICATE----- MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp ... Root Cert... d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA -----END CERTIFICATE----- ``` **TLS12SignatureAlgorithms**: Defines the allowed TLS 1.2 signature algorithms when SSLProvider is set to Internal.This configuration setting specifies the allowed server certificate signature algorithms when [SSLProvider](#sslprovider-property-mqttbroker-control) is set to *Internal* and [SSLEnabledProtocols](#SSLEnabledProtocols) is set to allow TLS 1.2. When specified the control will verify that the server certificate signature algorithm is among the values specified in this configuration setting. If the server certificate signature algorithm is unsupported, the control fails with an error. The format of this value is a comma-separated list of hash-signature combinations. For instance: ```csharp component.SSLProvider = TCPClientSSLProviders.sslpInternal; component.Config("SSLEnabledProtocols=3072"); //TLS 1.2 component.Config("TLS12SignatureAlgorithms=sha256-rsa,sha256-dsa,sha1-rsa,sha1-dsa"); ``` The default value for this configuration setting is *sha512-ecdsa,sha512-rsa,sha512-dsa,sha384-ecdsa,sha384-rsa,sha384-dsa,sha256-ecdsa,sha256-rsa,sha256-dsa,sha224-ecdsa,sha224-rsa,sha224-dsa,sha1-ecdsa,sha1-rsa,sha1-dsa*. To not restrict the server's certificate signature algorithm, specify an empty string as the value for this configuration setting, which will cause the signature_algorithms TLS 1.2 extension to not be sent. **TLS12SupportedGroups**: The supported groups for ECC.This configuration setting specifies a comma-separated list of named groups used in TLS 1.2 for ECC. The default value is *ecdhe_secp256r1,ecdhe_secp384r1,ecdhe_secp521r1*. When using TLS 1.2 and [SSLProvider](#sslprovider-property-mqttbroker-control) is set to *Internal*, the values refer to the supported groups for ECC. The following values are supported: - "ecdhe_secp256r1" (default) - "ecdhe_secp384r1" (default) - "ecdhe_secp521r1" (default) **TLS13KeyShareGroups**: The groups for which to pregenerate key shares.This configuration setting specifies a comma-separated list of named groups used in TLS 1.3 for key exchange. The groups specified here will have key share data pregenerated locally before establishing a connection. This can prevent an additional roundtrip during the handshake if the group is supported by the server. The default value is set to balance common supported groups and the computational resources required to generate key shares. As a result, only some groups are included by default in this configuration setting. NOTE: All supported groups can always be used during the handshake even if not listed here, but if a group is used that is not present in this list, it will incur an additional roundtrip and time to generate the key share for that group. In most cases, this configuration setting does not need to be modified. This should be modified only if there is a specific reason to do so. The default value is *ecdhe_x25519,ecdhe_secp256r1,ecdhe_secp384r1,ffdhe_2048,ffdhe_3072* The values are ordered from most preferred to least preferred. The following values are supported: - "ecdhe_x25519" (default) - "ecdhe_x448" - "ecdhe_secp256r1" (default) - "ecdhe_secp384r1" (default) - "ecdhe_secp521r1" - "ffdhe_2048" (default) - "ffdhe_3072" (default) - "ffdhe_4096" - "ffdhe_6144" - "ffdhe_8192" **TLS13SignatureAlgorithms**: The allowed certificate signature algorithms.This configuration setting holds a comma-separated list of allowed signature algorithms. Possible values include the following: - "ed25519" (default) - "ed448" (default) - "ecdsa_secp256r1_sha256" (default) - "ecdsa_secp384r1_sha384" (default) - "ecdsa_secp521r1_sha512" (default) - "rsa_pkcs1_sha256" (default) - "rsa_pkcs1_sha384" (default) - "rsa_pkcs1_sha512" (default) - "rsa_pss_sha256" (default) - "rsa_pss_sha384" (default) - "rsa_pss_sha512" (default) The default value is *rsa_pss_sha256,rsa_pss_sha384,rsa_pss_sha512,rsa_pkcs1_sha256,rsa_pkcs1_sha384,rsa_pkcs1_sha512,ecdsa_secp256r1_sha256,ecdsa_secp384r1_sha384,ecdsa_secp521r1_sha512,ed25519,ed448*. This configuration setting is applicable only when [SSLEnabledProtocols](#SSLEnabledProtocols) includes TLS 1.3. **TLS13SupportedGroups**: The supported groups for (EC)DHE key exchange.This configuration setting specifies a comma-separated list of named groups used in TLS 1.3 for key exchange. This configuration setting should be modified only if there is a specific reason to do so. The default value is *ecdhe_x25519,ecdhe_x448,ecdhe_secp256r1,ecdhe_secp384r1,ecdhe_secp521r1,ffdhe_2048,ffdhe_3072,ffdhe_4096,ffdhe_6144,ffdhe_8192,mlkem_512,mlkem_768,mlkem_1024,x25519_mlkem_768,secp256r1_mlkem_768* The values are ordered from most preferred to least preferred. The following values are supported: - "ecdhe_x25519" (default) - "ecdhe_x448" (default) - "ecdhe_secp256r1" (default) - "ecdhe_secp384r1" (default) - "ecdhe_secp521r1" (default) - "ffdhe_2048" (default) - "ffdhe_3072" (default) - "ffdhe_4096" (default) - "ffdhe_6144" (default) - "ffdhe_8192" (default) - "mlkem_512" (default) - "mlkem_768" (default) - "mlkem_1024" (default) - "x25519_mlkem_768" (default) - "secp256r1_mlkem_768" (default) Post-quantum algorithms (*mlkem_512,mlkem_768,mlkem_1024,x25519_mlkem_768,secp256r1_mlkem_768*) in our components rely on the operating system's underlying cryptographic primitives. The following platforms are currently supported: - Windows Server 2025 - Windows 11 24H2 - Windows 11 25H2 ### Socket Config Settings **AbsoluteTimeout**: Determines whether timeouts are inactivity timeouts or absolute timeouts.If [AbsoluteTimeout](#AbsoluteTimeout) is set to True, any method that does not complete within Timeout seconds will be aborted. By default, *AbsoluteTimeout* is False, and the timeout is an inactivity timeout. NOTE: This option is not valid for User Datagram Protocol (UDP) ports. **FirewallData**: Used to send extra data to the firewall.When the firewall is a tunneling proxy, use this property to send custom (additional) headers to the firewall (e.g., headers for custom authentication schemes). **InBufferSize**: The size in bytes of the incoming queue of the socket.This is the size of an internal queue in the Transmission Control Protocol (TCP)/IP stack. You can increase or decrease its size depending on the amount of data that you will be receiving. In some cases, increasing the value of the *InBufferSize* setting can provide significant improvements in performance. Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the control is activated the *InBufferSize* reverts to its defined size. The same happens if you attempt to make it too large or too small. **OutBufferSize**: The size in bytes of the outgoing queue of the socket.This is the size of an internal queue in the TCP/IP stack. You can increase or decrease its size depending on the amount of data that you will be sending. In some cases, increasing the value of the *OutBufferSize* setting can provide significant improvements in performance. Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the control is activated the *OutBufferSize* reverts to its defined size. The same happens if you attempt to make it too large or too small. ### Base Config Settings **CodePage**: The system code page used for Unicode to Multibyte translations.The default code page is Unicode UTF-8 (65001). The following is a list of valid code page identifiers: | | | | --- | --- | | Identifier | Name | | 037 | IBM EBCDIC - U.S./Canada | | 437 | OEM - United States | | 500 | IBM EBCDIC - International | | 708 | Arabic - ASMO 708 | | 709 | Arabic - ASMO 449+, BCON V4 | | 710 | Arabic - Transparent Arabic | | 720 | Arabic - Transparent ASMO | | 737 | OEM - Greek (formerly 437G) | | 775 | OEM - Baltic | | 850 | OEM - Multilingual Latin I | | 852 | OEM - Latin II | | 855 | OEM - Cyrillic (primarily Russian) | | 857 | OEM - Turkish | | 858 | OEM - Multilingual Latin I + Euro symbol | | 860 | OEM - Portuguese | | 861 | OEM - Icelandic | | 862 | OEM - Hebrew | | 863 | OEM - Canadian-French | | 864 | OEM - Arabic | | 865 | OEM - Nordic | | 866 | OEM - Russian | | 869 | OEM - Modern Greek | | 870 | IBM EBCDIC - Multilingual/ROECE (Latin-2) | | 874 | ANSI/OEM - Thai (same as 28605, ISO 8859-15) | | 875 | IBM EBCDIC - Modern Greek | | 932 | ANSI/OEM - Japanese, Shift-JIS | | 936 | ANSI/OEM - Simplified Chinese (PRC, Singapore) | | 949 | ANSI/OEM - Korean (Unified Hangul Code) | | 950 | ANSI/OEM - Traditional Chinese (Taiwan; Hong Kong SAR, PRC) | | 1026 | IBM EBCDIC - Turkish (Latin-5) | | 1047 | IBM EBCDIC - Latin 1/Open System | | 1140 | IBM EBCDIC - U.S./Canada (037 + Euro symbol) | | 1141 | IBM EBCDIC - Germany (20273 + Euro symbol) | | 1142 | IBM EBCDIC - Denmark/Norway (20277 + Euro symbol) | | 1143 | IBM EBCDIC - Finland/Sweden (20278 + Euro symbol) | | 1144 | IBM EBCDIC - Italy (20280 + Euro symbol) | | 1145 | IBM EBCDIC - Latin America/Spain (20284 + Euro symbol) | | 1146 | IBM EBCDIC - United Kingdom (20285 + Euro symbol) | | 1147 | IBM EBCDIC - France (20297 + Euro symbol) | | 1148 | IBM EBCDIC - International (500 + Euro symbol) | | 1149 | IBM EBCDIC - Icelandic (20871 + Euro symbol) | | 1200 | Unicode UCS-2 Little-Endian (BMP of ISO 10646) | | 1201 | Unicode UCS-2 Big-Endian | | 1250 | ANSI - Central European | | 1251 | ANSI - Cyrillic | | 1252 | ANSI - Latin I | | 1253 | ANSI - Greek | | 1254 | ANSI - Turkish | | 1255 | ANSI - Hebrew | | 1256 | ANSI - Arabic | | 1257 | ANSI - Baltic | | 1258 | ANSI/OEM - Vietnamese | | 1361 | Korean (Johab) | | 10000 | MAC - Roman | | 10001 | MAC - Japanese | | 10002 | MAC - Traditional Chinese (Big5) | | 10003 | MAC - Korean | | 10004 | MAC - Arabic | | 10005 | MAC - Hebrew | | 10006 | MAC - Greek I | | 10007 | MAC - Cyrillic | | 10008 | MAC - Simplified Chinese (GB 2312) | | 10010 | MAC - Romania | | 10017 | MAC - Ukraine | | 10021 | MAC - Thai | | 10029 | MAC - Latin II | | 10079 | MAC - Icelandic | | 10081 | MAC - Turkish | | 10082 | MAC - Croatia | | 12000 | Unicode UCS-4 Little-Endian | | 12001 | Unicode UCS-4 Big-Endian | | 20000 | CNS - Taiwan | | 20001 | TCA - Taiwan | | 20002 | Eten - Taiwan | | 20003 | IBM5550 - Taiwan | | 20004 | TeleText - Taiwan | | 20005 | Wang - Taiwan | | 20105 | IA5 IRV International Alphabet No. 5 (7-bit) | | 20106 | IA5 German (7-bit) | | 20107 | IA5 Swedish (7-bit) | | 20108 | IA5 Norwegian (7-bit) | | 20127 | US-ASCII (7-bit) | | 20261 | T.61 | | 20269 | ISO 6937 Non-Spacing Accent | | 20273 | IBM EBCDIC - Germany | | 20277 | IBM EBCDIC - Denmark/Norway | | 20278 | IBM EBCDIC - Finland/Sweden | | 20280 | IBM EBCDIC - Italy | | 20284 | IBM EBCDIC - Latin America/Spain | | 20285 | IBM EBCDIC - United Kingdom | | 20290 | IBM EBCDIC - Japanese Katakana Extended | | 20297 | IBM EBCDIC - France | | 20420 | IBM EBCDIC - Arabic | | 20423 | IBM EBCDIC - Greek | | 20424 | IBM EBCDIC - Hebrew | | 20833 | IBM EBCDIC - Korean Extended | | 20838 | IBM EBCDIC - Thai | | 20866 | Russian - KOI8-R | | 20871 | IBM EBCDIC - Icelandic | | 20880 | IBM EBCDIC - Cyrillic (Russian) | | 20905 | IBM EBCDIC - Turkish | | 20924 | IBM EBCDIC - Latin-1/Open System (1047 + Euro symbol) | | 20932 | JIS X 0208-1990 & 0121-1990 | | 20936 | Simplified Chinese (GB2312) | | 21025 | IBM EBCDIC - Cyrillic (Serbian, Bulgarian) | | 21027 | Extended Alpha Lowercase | | 21866 | Ukrainian (KOI8-U) | | 28591 | ISO 8859-1 Latin I | | 28592 | ISO 8859-2 Central Europe | | 28593 | ISO 8859-3 Latin 3 | | 28594 | ISO 8859-4 Baltic | | 28595 | ISO 8859-5 Cyrillic | | 28596 | ISO 8859-6 Arabic | | 28597 | ISO 8859-7 Greek | | 28598 | ISO 8859-8 Hebrew | | 28599 | ISO 8859-9 Latin 5 | | 28605 | ISO 8859-15 Latin 9 | | 29001 | Europa 3 | | 38598 | ISO 8859-8 Hebrew | | 50220 | ISO 2022 Japanese with no halfwidth Katakana | | 50221 | ISO 2022 Japanese with halfwidth Katakana | | 50222 | ISO 2022 Japanese JIS X 0201-1989 | | 50225 | ISO 2022 Korean | | 50227 | ISO 2022 Simplified Chinese | | 50229 | ISO 2022 Traditional Chinese | | 50930 | Japanese (Katakana) Extended | | 50931 | US/Canada and Japanese | | 50933 | Korean Extended and Korean | | 50935 | Simplified Chinese Extended and Simplified Chinese | | 50936 | Simplified Chinese | | 50937 | US/Canada and Traditional Chinese | | 50939 | Japanese (Latin) Extended and Japanese | | 51932 | EUC - Japanese | | 51936 | EUC - Simplified Chinese | | 51949 | EUC - Korean | | 51950 | EUC - Traditional Chinese | | 52936 | HZ-GB2312 Simplified Chinese | | 54936 | Windows XP: GB18030 Simplified Chinese (4 Byte) | | 57002 | ISCII Devanagari | | 57003 | ISCII Bengali | | 57004 | ISCII Tamil | | 57005 | ISCII Telugu | | 57006 | ISCII Assamese | | 57007 | ISCII Oriya | | 57008 | ISCII Kannada | | 57009 | ISCII Malayalam | | 57010 | ISCII Gujarati | | 57011 | ISCII Punjabi | | 65000 | Unicode UTF-7 | | 65001 | Unicode UTF-8 | The following is a list of valid code page identifiers for Mac OS only: | | | | --- | --- | | Identifier | Name | | 1 | ASCII | | 2 | NEXTSTEP | | 3 | JapaneseEUC | | 4 | UTF8 | | 5 | ISOLatin1 | | 6 | Symbol | | 7 | NonLossyASCII | | 8 | ShiftJIS | | 9 | ISOLatin2 | | 10 | Unicode | | 11 | WindowsCP1251 | | 12 | WindowsCP1252 | | 13 | WindowsCP1253 | | 14 | WindowsCP1254 | | 15 | WindowsCP1250 | | 21 | ISO2022JP | | 30 | MacOSRoman | | 10 | UTF16String | | 0x90000100 | UTF16BigEndian | | 0x94000100 | UTF16LittleEndian | | 0x8c000100 | UTF32String | | 0x98000100 | UTF32BigEndian | | 0x9c000100 | UTF32LittleEndian | | 65536 | Proprietary | **MaskSensitiveData**: Whether sensitive data is masked in log messages.In certain circumstances it may be beneficial to mask sensitive data, like passwords, in log messages. Set this to *True* to mask sensitive data. The default is *True*. **UseInternalSecurityAPI**: Whether or not to use the system security libraries or an internal implementation. When set to *False*, the control will use the system security libraries by default to perform cryptographic functions where applicable. Setting this configuration setting to *True* tells the control to use the internal implementation instead of using the system security libraries. This setting is set to *False* by default on all platforms. # Trappable Errors ([MQTTBroker](#mqttbroker-control) Control) ### MQTTBroker Errors | | | | --- | --- | | 20601 | MQTT protocol error. Refer to the error message for more information. | | 20602 | Invalid topic name. Refer to the error message for more information. | ### TCPClient Errors | | | | --- | --- | | 20101 | You cannot change the RemotePort at this time. A connection is in progress. | | 20102 | You cannot change the RemoteHost (Server) at this time. A connection is in progress. | | 20103 | The RemoteHost address is invalid (0.0.0.0). | | 20105 | Already connected. If you want to reconnect, close the current connection first. | | 20107 | You cannot change the LocalPort at this time. A connection is in progress. | | 20108 | You cannot change the LocalHost at this time. A connection is in progress. | | 20113 | You cannot change [MaxLineLength](#MaxLineLength) at this time. A connection is in progress. | | 20117 | RemotePort cannot be zero. Please specify a valid service port number. | | 20118 | You cannot change the UseConnection option while the control is active. | | 20136 | Operation would block. | | 20202 | Timeout. | | 20212 | Action impossible in control's present state. | | 20213 | Action impossible while not connected. | | 20214 | Action impossible while listening. | | 20302 | Timeout. | | 20303 | Could not open file. | | 20435 | Unable to convert string to selected CodePage. | | 21106 | Already connecting. If you want to reconnect, close the current connection first. | | 21118 | You need to connect first. | | 21120 | You cannot change the LocalHost at this time. A connection is in progress. | | 21121 | Connection dropped by remote host. | ### SSL Errors | | | | --- | --- | | 20271 | Cannot load specified security library. | | 20272 | Cannot open certificate store. | | 20273 | Cannot find specified certificate. | | 20274 | Cannot acquire security credentials. | | 20275 | Cannot find certificate chain. | | 20276 | Cannot verify certificate chain. | | 20277 | Error during handshake. | | 20281 | Error verifying certificate. | | 20282 | Could not find client certificate. | | 20283 | Could not find server certificate. | | 20284 | Error encrypting data. | | 20285 | Error decrypting data. | ### TCP/IP Errors | | | | --- | --- | | 25005 | [10004] Interrupted system call. | | 25010 | [10009] Bad file number. | | 25014 | [10013] Access denied. | | 25015 | [10014] Bad address. | | 25023 | [10022] Invalid argument. | | 25025 | [10024] Too many open files. | | 25036 | [10035] Operation would block. | | 25037 | [10036] Operation now in progress. | | 25038 | [10037] Operation already in progress. | | 25039 | [10038] Socket operation on nonsocket. | | 25040 | [10039] Destination address required. | | 25041 | [10040] Message is too long. | | 25042 | [10041] Protocol wrong type for socket. | | 25043 | [10042] Bad protocol option. | | 25044 | [10043] Protocol is not supported. | | 25045 | [10044] Socket type is not supported. | | 25046 | [10045] Operation is not supported on socket. | | 25047 | [10046] Protocol family is not supported. | | 25048 | [10047] Address family is not supported by protocol family. | | 25049 | [10048] Address already in use. | | 25050 | [10049] Cannot assign requested address. | | 25051 | [10050] Network is down. | | 25052 | [10051] Network is unreachable. | | 25053 | [10052] Net dropped connection or reset. | | 25054 | [10053] Software caused connection abort. | | 25055 | [10054] Connection reset by peer. | | 25056 | [10055] No buffer space available. | | 25057 | [10056] Socket is already connected. | | 25058 | [10057] Socket is not connected. | | 25059 | [10058] Cannot send after socket shutdown. | | 25060 | [10059] Too many references, cannot splice. | | 25061 | [10060] Connection timed out. | | 25062 | [10061] Connection refused. | | 25063 | [10062] Too many levels of symbolic links. | | 25064 | [10063] File name is too long. | | 25065 | [10064] Host is down. | | 25066 | [10065] No route to host. | | 25067 | [10066] Directory is not empty | | 25068 | [10067] Too many processes. | | 25069 | [10068] Too many users. | | 25070 | [10069] Disc Quota Exceeded. | | 25071 | [10070] Stale NFS file handle. | | 25072 | [10071] Too many levels of remote in path. | | 25092 | [10091] Network subsystem is unavailable. | | 25093 | [10092] WINSOCK DLL Version out of range. | | 25094 | [10093] Winsock is not loaded yet. | | 26002 | [11001] Host not found. | | 26003 | [11002] Nonauthoritative 'Host not found' (try again or check DNS setup). | | 26004 | [11003] Nonrecoverable errors: FORMERR, REFUSED, NOTIMP. | | 26005 | [11004] Valid name, no data record (check DNS setup). |