# TCPServer Component The TCPServer Component is a generic Transmission Control Protocol (TCP) server component based on an asynchronous, event-driven architecture. It is designed to balance the load between connections for a fast, powerful server. ## Syntax ```text nsoftware.IPWorks.TCPServer ``` ## Remarks The TCPServer Component supports both plaintext and Secure Sockets Layer/Transport Layer Security (SSL/TLS) connections. When connecting over Secure Sockets Layer/Transport Layer Security (SSL/TLS) the SSLServerAuthentication event allows you to check the server identity and other security attributes. The [SSLStatus](#sslstatus-event-tcpserver-component) event provides information about the SSL handshake. Additional SSL-related settings are also supported through the [Config](#config-method-tcpserver-component) method. The **SSLCert** properties are used to select a certificate for the server. NOTE: A valid certificate MUST be selected before the server can function. TCPServer is the server complement of TCPClient, which is used to create client applications. They share a common design philosophy and interface. We expect you will find TCPServer as easy to use as TCPClient. By default, each instance of TCPServer can handle up to 1,000 simultaneous incoming connections. This number may be increased up to 100,000 or decreased to a lower value by using the [MaxConnections](#MaxConnections) configuration setting. The connections are identified by a *ConnectionId*, an Id generated by the component to identify each connection. This Id is unique to each connection. TCPServer's events also have *ConnectionId* as a parameter to identify the connection they relate to. Our main goal in designing TCPServer was to make it easy to use without sacrificing performance. The component has a minimum number of properties, and six events: [ConnectionRequest](#connectionrequest-event-tcpserver-component), [Connected](#connected-event-tcpserver-component), [DataIn](#datain-event-tcpserver-component), [Disconnected](#disconnected-event-tcpserver-component), [ReadyToSend](#readytosend-event-tcpserver-component), and [Error](#error-event-tcpserver-component). TCPServer can start to listen on a port by setting the [Listening](#listening-property-tcpserver-component) property to True. When a remote host asks for a connection, the [ConnectionRequest](#connectionrequest-event-tcpserver-component) event is fired. At that point, the connection can either be accepted or rejected. If the connection is accepted, a *ConnectionId* is assigned, and communication can start. From this point on, the operation is very similar to TCPClient. Data are sent by assigning the data string to the *Text* parameter of the [Send](#send-method-tcpserver-component) method. The address and port of the incoming connection can be found by querying the RemoteHost and RemotePort properties. **Threading in Server Applications** In .NET, all socket-based components perform all Socket.IO through asynchronous methods. Each call consumes a thread from the system's thread pool, and thus the number of concurrent calls is limited to the number of worker threads returned by ***System.Threading.ThreadPool.GetMaxThreads***. When using several components that can each create a socket connection or a single component that can create multiple socket connections, the application may enter a state in which all of the pool threads are in use for receiving. In a scenario such as this, the remote hosts may be waiting for data from the application before sending, but the application cannot send that data because all the threads are tied up waiting for inbound data. This is particularly important for server applications that use a daemon component. For example, say a server application 'S' has a max thread pool size of three, and clients 'A' and 'B' connect to it and each client uploads a large file. After all uploads are complete, 'S' enqueues an asynchronous read request in the thread pool for each client. Because no work is being done, the thread pool immediately consumes two threads that wait for any further data from 'A' and 'B'. While 'S' is still processing the first two files it has received, client 'C' connects and uploads a relatively small file. Similarly, once that upload has completed 'S' enqueues a third read request, and the thread pool immediately consumes the third and final thread to wait for further data from 'C'. Once 'S' completes processing any of the files, it will enqueue a send request. However, because all three threads are in use and waiting for data from the clients, the send operation cannot be completed. The entire system becomes deadlocked because each of the clients is waiting for data from the server, which cannot send that data because all of its pool threads are in turn waiting for data from the clients. To avoid a deadlock situation such as this, it is necessary to ensure that the maximum number of socket connections an application can make is always at least one less than the number of available worker threads. One method to achieve this is to call ***System.Threading.ThreadPool.SetMaxThreads*** during the application's startup to set the maximum number of threads to a value high enough to support the application for the duration of its execution. Another option is to trap an event such as [ConnectionRequest](#connectionrequest-event-tcpserver-component) and [Disconnected](#disconnected-event-tcpserver-component) from each component instance with logic to manage the maximum thread pool size according to the application's current needs. NOTE: Server components are designed to process events as they occur. To ensure that events are processed in a timely manner, [DoEvents](#doevents-method-tcpserver-component) should be called in a loop after the server is started. ## Property List *The following is the full list of the properties of the component with short descriptions. Click on the links for further details.* | | | | --- | --- | | [ConnectionBacklog](#connectionbacklog-property-tcpserver-component) | This property includes the maximum number of pending connections maintained by the Transmission Control Protocol (TCP)/IP subsystem. | | [Connections](#connections-property-tcpserver-component) | This property includes a collection of currently connected clients. | | [DefaultEOL](#defaulteol-property-tcpserver-component) | This property includes a default end-of-line (EOL) value to be used by incoming connections. | | [DefaultIdleTimeout](#defaultidletimeout-property-tcpserver-component) | This property includes the default idle timeout for inactive clients. | | [DefaultMaxLineLength](#defaultmaxlinelength-property-tcpserver-component) | The property includes the default maximum line length value for inbound connections. | | [DefaultSingleLineMode](#defaultsinglelinemode-property-tcpserver-component) | This property tells the component whether or not to treat new connections as line oriented. | | [DefaultTimeout](#defaulttimeout-property-tcpserver-component) | This property includes an initial timeout value to be used by incoming connections. | | [KeepAlive](#keepalive-property-tcpserver-component) | When True, KEEPALIVE packets are enabled (for long connections). | | [Linger](#linger-property-tcpserver-component) | When set to True, connections are terminated gracefully. | | [Listening](#listening-property-tcpserver-component) | This property indicates whether the component is listening for incoming connections on LocalPort. | | [LocalHost](#localhost-property-tcpserver-component) | The name of the local host or user-assigned IP interface through which connections are initiated or accepted. | | [LocalPort](#localport-property-tcpserver-component) | This property includes the Transmission Control Protocol (TCP) port in the local host where the component listens. | | [SSLAuthenticateClients](#sslauthenticateclients-property-tcpserver-component) | If set to True, the server asks the client(s) for a certificate. | | [SSLCert](#sslcert-property-tcpserver-component) | The certificate to be used during Secure Sockets Layer (SSL) negotiation. | | [SSLEnabled](#sslenabled-property-tcpserver-component) | This property indicates whether Transport Layer Security/Secure Sockets Layer (TLS/SSL) is enabled. | | [SSLProvider](#sslprovider-property-tcpserver-component) | The Secure Sockets Layer/Transport Layer Security (SSL/TLS) implementation to use. | | [SSLStartMode](#sslstartmode-property-tcpserver-component) | This property determines how the component starts the Secure Sockets Layer (SSL) negotiation. | ## Method List *The following is the full list of the methods of the component with short descriptions. Click on the links for further details.* | | | | --- | --- | | [ChangeRecordLength](#changerecordlength-method-tcpserver-component) | This method changes the length of received data records. | | [Config](#config-method-tcpserver-component) | Sets or retrieves a configuration setting. | | [Disconnect](#disconnect-method-tcpserver-component) | This method disconnects the specified client. | | [DoEvents](#doevents-method-tcpserver-component) | This method processes events from the internal message queue. | | [Interrupt](#interrupt-method-tcpserver-component) | This method interrupts a synchronous send to the remote host. | | [PauseData](#pausedata-method-tcpserver-component) | This method pauses data reception. | | [ProcessData](#processdata-method-tcpserver-component) | This method reenables data reception after a call to [PauseData](#pausedata-method-tcpserver-component) . | | [Reset](#reset-method-tcpserver-component) | This method will reset the component. | | [Send](#send-method-tcpserver-component) | This method sends binary data to the specified client. | | [SendBytes](#sendbytes-method-tcpserver-component) | This method sends binary data to the specified client. | | [SendFile](#sendfile-method-tcpserver-component) | This method sends the file to the remote host. | | [SendLine](#sendline-method-tcpserver-component) | This method sends a string followed by a new line. | | [SendText](#sendtext-method-tcpserver-component) | This method sends text to the specified client. | | [SetUploadStream](#setuploadstream-method-tcpserver-component) | This method uploads the data in the specified stream. | | [Shutdown](#shutdown-method-tcpserver-component) | This method shuts down the server. | | [StartListening](#startlistening-method-tcpserver-component) | This method starts listening for incoming connections. | | [StartSSL](#startssl-method-tcpserver-component) | This method starts the Secure Sockets Layer (SSL) negotiation on a connection. | | [StopListening](#stoplistening-method-tcpserver-component) | This method stops listening for new connections. | ## Event List *The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.* | | | | --- | --- | | [Connected](#connected-event-tcpserver-component) | This event is fired immediately after a connection completes (or fails). | | [ConnectionRequest](#connectionrequest-event-tcpserver-component) | This event is fired when a request for connection comes from a remote host. | | [DataIn](#datain-event-tcpserver-component) | This event is fired when data come in. | | [Disconnected](#disconnected-event-tcpserver-component) | This event is fired when a connection is closed. | | [Error](#error-event-tcpserver-component) | This event fires information about errors during data delivery. | | [ReadyToSend](#readytosend-event-tcpserver-component) | This event is fired when the component is ready to send data. | | [SSLClientAuthentication](#sslclientauthentication-event-tcpserver-component) | This event is fired when the client presents its credentials to the server. | | [SSLConnectionRequest](#sslconnectionrequest-event-tcpserver-component) | This event fires when a Secure Sockets Layer (SSL) connection is requested. | | [SSLStatus](#sslstatus-event-tcpserver-component) | This event is fired to show the progress of the secure connection. | ## Config Settings *The following is a list of config settings for the component with short descriptions. Click on the links for further details.* | | | | --- | --- | | [AllowedClients](#AllowedClients) | A comma-separated list of host names or IP addresses that can access the component. | | [BindExclusively](#BindExclusively) | Whether or not the component considers a local port reserved for exclusive use. | | [BlockedClients](#BlockedClients) | A comma-separated list of host names or IP addresses that cannot access the component. | | [CloseStreamAfterTransfer](#CloseStreamAfterTransfer) | If true, the component will close the upload or download stream after the transfer. | | [DefaultConnectionTimeout](#DefaultConnectionTimeout) | The inactivity timeout applied to the SSL handshake. | | [InBufferSize](#InBufferSize) | The size in bytes of the incoming queue of the socket. | | [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. | | [MaxConnections](#MaxConnections) | The maximum number of connections available. | | [OutBufferSize](#OutBufferSize) | The size in bytes of the outgoing queue of the socket. | | [PreferredDHGroupBits](#PreferredDHGroupBits) | Size of the Diffie-Hellman group, in bits. | | [TcpNoDelay](#TcpNoDelay) | Whether or not to delay when sending packets. | | [UseBackgroundThread](#UseBackgroundThread) | Whether threads created by the component are background threads. | | [UseIPv6](#UseIPv6) | Whether to use IPv6. | | [CACertFilePaths](#CACertFilePaths) | The paths to CA certificate files when using Mono on Unix/Linux. | | [LogSSLPackets](#LogSSLPackets) | Controls whether SSL packets are logged when using the internal security API. | | [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. | | [BuildInfo](#BuildInfo) | Information about the product's build. | | [GUIAvailable](#GUIAvailable) | Whether or not a message loop is available for processing events. | | [LicenseInfo](#LicenseInfo) | Information about the current license. | | [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. | # ConnectionBacklog Property ([TCPServer](#tcpserver-component) Component) This property includes the maximum number of pending connections maintained by the Transmission Control Protocol (TCP)/IP subsystem. ## Syntax ```text public int ConnectionBacklog { get; set; } ``` ## Default Value 5 ## Remarks This property contains the maximum number of pending connections maintained by the TCP/IP subsystem. This value reflects the SOMAXCONN option for the main listening socket. The default value for most systems is 5. You may set this property to a larger value if the server is expected to receive a large number of connections, and queuing them is desirable. This property is not available at design time. # Connections Property ([TCPServer](#tcpserver-component) Component) This property includes a collection of currently connected clients. ## Syntax ```text public ConnectionMap Connections { get; } ``` ## Remarks This property contains a collection of currently connected clients. All of the connections may be managed using this property. Each connection is described by the different fields of the [Connection](#connection-type) type. This collection is a hash-table type of collection, in which the Connection Id string is used as the key to the desired connection. You may acquire the key for a given connection through the [Connected](#connected-event-tcpserver-component) event. **Example (Broadcasting Data)** ```text foreach (Connection c in tcpserver1.Connections.Values) { c.DataToSend = "Broadcast Data"; } ``` This property is read-only. Please refer to the [Connection](#connection-type) type for a complete list of fields. # DefaultEOL Property ([TCPServer](#tcpserver-component) Component) This property includes a default end-of-line (EOL) value to be used by incoming connections. ## Syntax ```text public string DefaultEOL { get; set; } public byte[] DefaultEOLB { get; set; } ``` ## Default Value "" ## Remarks This property contains a default end-of-line (EOL) value to be used by incoming connections. Once the component accepts and establishes an inbound connection, it will set that connection's EOL to the value in this property. By default, this value is empty (""), meaning that data will be fired as it is received. # DefaultIdleTimeout Property ([TCPServer](#tcpserver-component) Component) This property includes the default idle timeout for inactive clients. ## Syntax ```text public int DefaultIdleTimeout { get; set; } ``` ## Default Value 0 ## Remarks This property specifies the idle timeout (in seconds) for clients. When set to a positive value, the component 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-tcpserver-component) must be called for the component to check existing connections. # DefaultMaxLineLength Property ([TCPServer](#tcpserver-component) Component) The property includes the default maximum line length value for inbound connections. ## Syntax ```text public int DefaultMaxLineLength { get; set; } ``` ## Default Value 2048 ## Remarks This property controls the default size of an internal buffer that holds received data while waiting for an end-of-line (EOL) string. The minimum value for this property is 256 bytes. The default value is 2048 bytes. # DefaultSingleLineMode Property ([TCPServer](#tcpserver-component) Component) This property tells the component whether or not to treat new connections as line oriented. ## Syntax ```text public bool DefaultSingleLineMode { get; set; } ``` ## Default Value False ## Remarks This property instructs the component whether or not to treat newly established connections as line-oriented protocols. If this value is True, newly accepted connections will read the incoming data stream as lines separated by a carriage return line feed (CRLF), carriage return (CR), or line feed (LF) and will ignore the end of lines (EOLs). # DefaultTimeout Property ([TCPServer](#tcpserver-component) Component) This property includes an initial timeout value to be used by incoming connections. ## Syntax ```text public int DefaultTimeout { get; set; } ``` ## Default Value 0 ## Remarks This property is used by the component to set the operational timeout value of all inbound connections once they are established. This property defines the timeout when sending data. When [SSLEnabled](#sslenabled-property-tcpserver-component) is False, a value of 0 means data will be sent asynchronously, and a positive value means data is sent synchronously. When [SSLEnabled](#sslenabled-property-tcpserver-component) is True, all data are sent synchronously regardless of the Timeout value. # KeepAlive Property ([TCPServer](#tcpserver-component) Component) When True, * KEEPALIVE * packets are enabled (for long connections). ## Syntax ```text public bool KeepAlive { get; set; } ``` ## Default Value False ## Remarks 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. # Linger Property ([TCPServer](#tcpserver-component) Component) When set to True, connections are terminated gracefully. ## Syntax ```text public bool Linger { get; set; } ``` ## Default Value True ## Remarks This property controls how a connection is closed. The default is True. In this case, the connection is closed only after all the data are sent. Setting it to False forces an abrupt (hard) disconnection. Any data that were in the sending queue may be lost. The default behavior (which is also the default mode for stream sockets) might result in an indefinite delay in closing the connection. Although the component returns control immediately, the system might indefinitely hold system resources until all pending data are sent (even after your application closes). This means that valuable system resources might be wasted. Setting this property to False forces an immediate disconnection. If you know that the other side has received all the data you have sent (e.g., by a client acknowledgment), then setting this property to False might be the appropriate course of action. 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. # Listening Property ([TCPServer](#tcpserver-component) Component) This property indicates whether the component is listening for incoming connections on LocalPort. ## Syntax ```text public bool Listening { get; } ``` ## Default Value False ## Remarks This property indicates whether the component is listening for connections on the port specified by the [LocalPort](#localport-property-tcpserver-component) property. Use the [StartListening](#startlistening-method-tcpserver-component) and [StopListening](#stoplistening-method-tcpserver-component) methods to control whether the component is listening. This property is read-only and not available at design time. # LocalHost Property ([TCPServer](#tcpserver-component) Component) The name of the local host or user-assigned IP interface through which connections are initiated or accepted. ## Syntax ```text public string LocalHost { get; set; } ``` ## Default Value "" ## Remarks This property 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 IP address of an interface will make the component initiate connections (or accept in the case of server components) only through that interface. It is recommended to provide an IP address rather than a hostname when setting this property to ensure the desired interface is used. If the component is connected, the LocalHost property 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). NOTE: LocalHost is not persistent. You must always set it in code, and never in the property window. # LocalPort Property ([TCPServer](#tcpserver-component) Component) This property includes the Transmission Control Protocol (TCP) port in the local host where the component listens. ## Syntax ```text public int LocalPort { get; set; } ``` ## Default Value 0 ## Remarks This property must be set before the component can start listening. If its value is 0, then the TCP/IP subsystem picks a port number at random. The port number can be found by checking the value of this property after the component is listening (i.e., after successfully assigning True to the [Listening](#listening-property-tcpserver-component) property). The service port is not shared among servers so two components cannot be listening on the same port at the same time. # SSLAuthenticateClients Property ([TCPServer](#tcpserver-component) Component) If set to True, the server asks the client(s) for a certificate. ## Syntax ```text public bool SSLAuthenticateClients { get; set; } ``` ## Default Value False ## Remarks This property is used in conjunction with the [SSLClientAuthentication](#sslclientauthentication-event-tcpserver-component) event. Please refer to the documentation of the [SSLClientAuthentication](#sslclientauthentication-event-tcpserver-component) event for details. # SSLCert Property ([TCPServer](#tcpserver-component) Component) The certificate to be used during Secure Sockets Layer (SSL) negotiation. ## Syntax ```text public Certificate SSLCert { get; set; } ``` ## Remarks This property includes the digital certificate that the component will use during SSL negotiation. Set this property to a valid certificate before starting SSL negotiation. To set a certificate, you may set the [Encoded](#Certificate_f_Encoded) field to the encoded certificate. To select a certificate, use the store and subject fields. Please refer to the [Certificate](#certificate-type) type for a complete list of fields. # SSLEnabled Property ([TCPServer](#tcpserver-component) Component) This property indicates whether Transport Layer Security/Secure Sockets Layer (TLS/SSL) is enabled. ## Syntax ```text public bool SSLEnabled { get; set; } ``` ## Default Value False ## Remarks This property specifies whether TLS/SSL is enabled in the component. When False (default), the component operates in plaintext mode. When True, TLS/SSL is enabled. TLS/SSL may also be enabled by setting [SSLStartMode](#sslstartmode-property-tcpserver-component). Setting [SSLStartMode](#sslstartmode-property-tcpserver-component) will automatically update this property value. This property is not available at design time. # SSLProvider Property ([TCPServer](#tcpserver-component) Component) The Secure Sockets Layer/Transport Layer Security (SSL/TLS) implementation to use. ## Syntax ```text public TCPServerSSLProviders SSLProvider { get; set; } enum TCPServerSSLProviders { sslpAutomatic, sslpPlatform, sslpInternal } ``` ## 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 component 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 component will select a provider depending on the current platform. When Automatic is selected, on Windows, the component will use the platform implementation. On Linux/macOS, the component will use the internal implementation. When TLS 1.3 is enabled via [SSLEnabledProtocols](#SSLEnabledProtocols), the component will always try and use the platform implementation. If the platform TLS 1.3 implementation is not available, the internal implementation will be used. The .NET Standard library will always use the internal implementation on all platforms. # SSLStartMode Property ([TCPServer](#tcpserver-component) Component) This property determines how the component starts the Secure Sockets Layer (SSL) negotiation. ## Syntax ```text public TCPServerSSLStartModes SSLStartMode { get; set; } enum TCPServerSSLStartModes { sslAutomatic, sslImplicit, sslExplicit, sslNone } ``` ## Default Value 3 ## Remarks The SSLStartMode property may have one of the following values: | | | | --- | --- | | 0 (sslAutomatic) | If the remote port is set to the standard plaintext port of the protocol (where applicable), the component will behave the same as if SSLStartMode is set to sslExplicit. In all other cases, SSL negotiation will be implicit (sslImplicit). | | 1 (sslImplicit) | The SSL negotiation will start immediately after the connection is established. | | 2 (sslExplicit) | The component will first connect in plaintext, and then will explicitly start SSL negotiation through a protocol command such as STARTTLS. | | 3 (sslNone - default) | No SSL negotiation; no SSL security. All communication will be in plaintext mode. | # ChangeRecordLength Method ([TCPServer](#tcpserver-component) Component) This method changes the length of received data records. ## Syntax ```text public void ChangeRecordLength(string connectionId, int recordLength); Async Version public async Task ChangeRecordLength(string connectionId, int recordLength); public async Task ChangeRecordLength(string connectionId, int recordLength, CancellationToken cancellationToken); ``` ## Remarks This method defines the length of data records to be received (in bytes) for the specified *ConnectionId*. If *RecordLength* is set to a positive value, the component will accumulate data until *RecordLength* bytes of data are received and only then will fire the [DataIn](#datain-event-tcpserver-component) event with data of the specified length *RecordLength*. This allows data to be received as records of known length. This method can be called at any time to change the record length, including within the [DataIn](#datain-event-tcpserver-component) event. A value of 0 (default) means this functionality is not used. # Config Method ([TCPServer](#tcpserver-component) Component) Sets or retrieves a configuration setting. ## Syntax ```text public string Config(string configurationString); Async Version public async Task Config(string configurationString); public async Task Config(string configurationString, CancellationToken cancellationToken); ``` ## Remarks Config is a generic method available in every component. It is used to set and retrieve [configuration settings](#config-settings-tcpserver-component) for the component. These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, 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-tcpserver-component), you must call *Config("PROPERTY")*. The value will be returned as a string. # Disconnect Method ([TCPServer](#tcpserver-component) Component) This method disconnects the specified client. ## Syntax ```text public void Disconnect(string connectionId); Async Version public async Task Disconnect(string connectionId); public async Task Disconnect(string connectionId, CancellationToken cancellationToken); ``` ## Remarks Calling this method will disconnect the client specified by the *ConnectionId* parameter. # DoEvents Method ([TCPServer](#tcpserver-component) Component) This method processes events from the internal message queue. ## Syntax ```text public void DoEvents(); Async Version public async Task DoEvents(); public async Task DoEvents(CancellationToken cancellationToken); ``` ## Remarks When DoEvents is called, the component processes any available events. If no events are available, it waits for a preset period of time, and then returns. # Interrupt Method ([TCPServer](#tcpserver-component) Component) This method interrupts a synchronous send to the remote host. ## Syntax ```text public void Interrupt(string connectionId); Async Version public async Task Interrupt(string connectionId); public async Task Interrupt(string connectionId, CancellationToken cancellationToken); ``` ## 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 component. If you use [SendFile](#sendfile-method-tcpserver-component) to upload a file, the component will run synchronously on that Connection Id until it is completed. # PauseData Method ([TCPServer](#tcpserver-component) Component) This method pauses data reception. ## Syntax ```text public void PauseData(string connectionId); Async Version public async Task PauseData(string connectionId); public async Task PauseData(string connectionId, CancellationToken cancellationToken); ``` ## Remarks This method pauses data reception for the connection identified by *ConnectionId* when called. While data reception is paused, the [DataIn](#datain-event-tcpserver-component) event will not fire for the specified connection. Call [ProcessData](#processdata-method-tcpserver-component) to reenable data reception. # ProcessData Method ([TCPServer](#tcpserver-component) Component) This method reenables data reception after a call to [PauseData](#pausedata-method-tcpserver-component) . ## Syntax ```text public void ProcessData(string connectionId); Async Version public async Task ProcessData(string connectionId); public async Task ProcessData(string connectionId, CancellationToken cancellationToken); ``` ## Remarks This method reenables data reception for the connection identified by *ConnectionId* after a previous call to [PauseData](#pausedata-method-tcpserver-component). When [PauseData](#pausedata-method-tcpserver-component) is called, the [DataIn](#datain-event-tcpserver-component) event will not fire for the specified connection. To reenable data reception and allow [DataIn](#datain-event-tcpserver-component) to fire, call this method. NOTE: This method is used only after previously calling [PauseData](#pausedata-method-tcpserver-component). It does not need to be called to process incoming data by default. # Reset Method ([TCPServer](#tcpserver-component) Component) This method will reset the component. ## Syntax ```text public void Reset(); Async Version public async Task Reset(); public async Task Reset(CancellationToken cancellationToken); ``` ## Remarks This method will reset the component's properties to their default values. # Send Method ([TCPServer](#tcpserver-component) Component) This method sends binary data to the specified client. ## Syntax ```text public void Send(string connectionId, byte[] text); Async Version public async Task Send(string connectionId, byte[] text); public async Task Send(string connectionId, byte[] text, CancellationToken cancellationToken); ``` ## Remarks This method sends binary data to the client identified by *ConnectionId*. To send text, use the [SendText](#sendtext-method-tcpserver-component) method instead. When [Timeout](#Connection_f_Timeout) is set to 0 and [SSLEnabled](#sslenabled-property-tcpserver-component) is set to False, the component will behave asynchronously. If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, the operation fails with exception 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again. . The BytesSent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the [ReadyToSend](#readytosend-event-tcpserver-component) event before attempting to send data again. NOTE: The [ReadyToSend](#readytosend-event-tcpserver-component) event is not fired when part of the data is sent successfully. When [SSLEnabled](#sslenabled-property-tcpserver-component) is True or [Timeout](#Connection_f_Timeout) is set to a positive value, the component behaves synchronously. # SendBytes Method ([TCPServer](#tcpserver-component) Component) This method sends binary data to the specified client. ## Syntax ```text public void SendBytes(string connectionId, byte[] data); Async Version public async Task SendBytes(string connectionId, byte[] data); public async Task SendBytes(string connectionId, byte[] data, CancellationToken cancellationToken); ``` ## Remarks This method sends binary data to the client identified by *ConnectionId*. To send text, use the [SendText](#sendtext-method-tcpserver-component) method instead. When [Timeout](#Connection_f_Timeout) is set to 0 and [SSLEnabled](#sslenabled-property-tcpserver-component) is set to False, the component will behave asynchronously. If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, the operation fails with exception 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again. . The BytesSent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the [ReadyToSend](#readytosend-event-tcpserver-component) event before attempting to send data again. NOTE: The [ReadyToSend](#readytosend-event-tcpserver-component) event is not fired when part of the data is sent successfully. When [SSLEnabled](#sslenabled-property-tcpserver-component) is True or [Timeout](#Connection_f_Timeout) is set to a positive value, the component behaves synchronously. # SendFile Method ([TCPServer](#tcpserver-component) Component) This method sends the file to the remote host. ## Syntax ```text public void SendFile(string connectionId, string fileName); Async Version public async Task SendFile(string connectionId, string fileName); public async Task SendFile(string connectionId, string fileName, CancellationToken cancellationToken); ``` ## Remarks This method sends the file to the client specified by the *ConnectionId*. Note: This method operate synchronously. [DefaultTimeout](#defaulttimeout-property-tcpserver-component) or [Timeout](#Connection_f_Timeout) must be set to a positive value before calling this method. # SendLine Method ([TCPServer](#tcpserver-component) Component) This method sends a string followed by a new line. ## Syntax ```text public void SendLine(string connectionId, string text); Async Version public async Task SendLine(string connectionId, string text); public async Task SendLine(string connectionId, string text, CancellationToken cancellationToken); ``` ## Remarks This method is used to send data with line-oriented protocols. The line is followed by CRLF (*"\r\n"*) . Please refer to the GetLine method and SingleLineMode property for more information. # SendText Method ([TCPServer](#tcpserver-component) Component) This method sends text to the specified client. ## Syntax ```text public void SendText(string connectionId, string text); Async Version public async Task SendText(string connectionId, string text); public async Task SendText(string connectionId, string text, CancellationToken cancellationToken); ``` ## Remarks This method sends text to the client identified by *ConnectionId*. To send binary data, use the [SendBytes](#sendbytes-method-tcpserver-component) method instead. When [Timeout](#Connection_f_Timeout) is set to 0 and [SSLEnabled](#sslenabled-property-tcpserver-component) is set to False, the component will behave asynchronously. If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, the operation fails with exception 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again. . The BytesSent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the [ReadyToSend](#readytosend-event-tcpserver-component) event before attempting to send data again. NOTE: The [ReadyToSend](#readytosend-event-tcpserver-component) event is not fired when part of the data is sent successfully. When [SSLEnabled](#sslenabled-property-tcpserver-component) is True or [Timeout](#Connection_f_Timeout) is set to a positive value, the component behaves synchronously. # SetUploadStream Method ([TCPServer](#tcpserver-component) Component) This method uploads the data in the specified stream. ## Syntax ```text public void SetUploadStream(string connectionId, System.IO.Stream stream); Async Version public async Task SetUploadStream(string connectionId, System.IO.Stream stream); public async Task SetUploadStream(string connectionId, System.IO.Stream stream, CancellationToken cancellationToken); ``` ## Remarks This method uploads the data in the specified stream to the connection identified by *ConnectionId*. The component will automatically close this stream if [CloseStreamAfterTransfer](#CloseStreamAfterTransfer) is *true* (default). # Shutdown Method ([TCPServer](#tcpserver-component) Component) This method shuts down the server. ## Syntax ```text public void Shutdown(); Async Version public async Task Shutdown(); public async Task Shutdown(CancellationToken cancellationToken); ``` ## Remarks This method shuts down the server. Calling this method is equivalent to calling [StopListening](#stoplistening-method-tcpserver-component) and then breaking every client connection by calling [Disconnect](#disconnect-method-tcpserver-component). # StartListening Method ([TCPServer](#tcpserver-component) Component) This method starts listening for incoming connections. ## Syntax ```text public void StartListening(); Async Version public async Task StartListening(); public async Task StartListening(CancellationToken cancellationToken); ``` ## Remarks This method begins listening for incoming connections on the port specified by [LocalPort](#localport-property-tcpserver-component). Once listening, events will fire as new clients connect and data are transferred. To stop listening for new connections, call [StopListening](#stoplistening-method-tcpserver-component). To stop listening for new connections and to disconnect all existing clients, call [Shutdown](#shutdown-method-tcpserver-component). # StartSSL Method ([TCPServer](#tcpserver-component) Component) This method starts the Secure Sockets Layer (SSL) negotiation on a connection. ## Syntax ```text public void StartSSL(string connectionId); Async Version public async Task StartSSL(string connectionId); public async Task StartSSL(string connectionId, CancellationToken cancellationToken); ``` ## Remarks This method is used to start the SSL negotiation on a plaintext connection. Please refer to the [SSLStartMode](#sslstartmode-property-tcpserver-component) property for more information. NOTE: The [Connected](#connected-event-tcpserver-component) event will fire again after the SSL negotiation is complete. # StopListening Method ([TCPServer](#tcpserver-component) Component) This method stops listening for new connections. ## Syntax ```text public void StopListening(); Async Version public async Task StopListening(); public async Task StopListening(CancellationToken cancellationToken); ``` ## 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-tcpserver-component) instead. # Connected Event ([TCPServer](#tcpserver-component) Component) This event is fired immediately after a connection completes (or fails). ## Syntax ```text public event OnConnectedHandler OnConnected; public delegate void OnConnectedHandler(object sender, TCPServerConnectedEventArgs e); public class TCPServerConnectedEventArgs : EventArgs { public string ConnectionId { get; } public int StatusCode { get; } public string Description { get; } } ``` ## 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. Please refer to the [Error Codes](#trappable-errors-tcpserver-component) section for more information. # ConnectionRequest Event ([TCPServer](#tcpserver-component) Component) This event is fired when a request for connection comes from a remote host. ## Syntax ```text public event OnConnectionRequestHandler OnConnectionRequest; public delegate void OnConnectionRequestHandler(object sender, TCPServerConnectionRequestEventArgs e); public class TCPServerConnectionRequestEventArgs : EventArgs { public string Address { get; } public int Port { get; } public bool Accept { get; set; } } ``` ## 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. # DataIn Event ([TCPServer](#tcpserver-component) Component) This event is fired when data come in. ## Syntax ```text public event OnDataInHandler OnDataIn; public delegate void OnDataInHandler(object sender, TCPServerDataInEventArgs e); public class TCPServerDataInEventArgs : EventArgs { public string ConnectionId { get; } public string Text { get; } public byte[] TextB { get; } public bool EOL { get; } } ``` ## Remarks Trapping the DataIn event is your only chance to get the data coming from the other end of the connection specified by *ConnectionId*. The incoming data are provided through the *Text* parameter. *EOL* indicates whether or not the EOL string was found at the end of *Text*. If the EOL string was found, then *EOL* is True. If Text is part of the data portion of length larger than either [DefaultMaxLineLength](#defaultmaxlinelength-property-tcpserver-component) or [MaxLineLength](#Connection_f_MaxLineLength) with no EOL strings in it, then *EOL* is False. Please note that this means that one or more DataIn events with *EOL* set to False can be received during a connection. If the EOL property is "" (empty string), then *EOL* can be disregarded (it is always True). NOTE: Events are not re-entrant. Performing time-consuming operations within this event will prevent it from firing again in a timely manner and may affect overall performance. # Disconnected Event ([TCPServer](#tcpserver-component) Component) This event is fired when a connection is closed. ## Syntax ```text public event OnDisconnectedHandler OnDisconnected; public delegate void OnDisconnectedHandler(object sender, TCPServerDisconnectedEventArgs e); public class TCPServerDisconnectedEventArgs : EventArgs { public string ConnectionId { get; } public int StatusCode { get; } public string Description { get; } } ``` ## 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. Please refer to the [Error Codes](#trappable-errors-tcpserver-component) section for more information. # Error Event ([TCPServer](#tcpserver-component) Component) This event fires information about errors during data delivery. ## Syntax ```text public event OnErrorHandler OnError; public delegate void OnErrorHandler(object sender, TCPServerErrorEventArgs e); public class TCPServerErrorEventArgs : EventArgs { public string ConnectionId { get; } public int ErrorCode { get; } public string Description { get; } } ``` ## Remarks The Error event is fired in case of exceptional conditions during message processing. Normally, the component throws an exception. *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-tcpserver-component) section. *ConnectionId* indicates the connection for which the error is applicable. # ReadyToSend Event ([TCPServer](#tcpserver-component) Component) This event is fired when the component is ready to send data. ## Syntax ```text public event OnReadyToSendHandler OnReadyToSend; public delegate void OnReadyToSendHandler(object sender, TCPServerReadyToSendEventArgs e); public class TCPServerReadyToSendEventArgs : EventArgs { public string ConnectionId { get; } } ``` ## Remarks The ReadyToSend event indicates that the underlying Transmission Control Protocol (TCP)/IP subsystem is ready to accept data after a failed [Send](#send-method-tcpserver-component). This event is also fired immediately after a connection is established. # SSLClientAuthentication Event ([TCPServer](#tcpserver-component) Component) This event is fired when the client presents its credentials to the server. ## Syntax ```text public event OnSSLClientAuthenticationHandler OnSSLClientAuthentication; public delegate void OnSSLClientAuthenticationHandler(object sender, TCPServerSSLClientAuthenticationEventArgs e); public class TCPServerSSLClientAuthenticationEventArgs : EventArgs { public string ConnectionId { get; } public string CertEncoded { get; } public byte[] CertEncodedB { get; } public string CertSubject { get; } public string CertIssuer { get; } public string Status { get; } public bool Accept { get; set; } } ``` ## 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"). # SSLConnectionRequest Event ([TCPServer](#tcpserver-component) Component) This event fires when a Secure Sockets Layer (SSL) connection is requested. ## Syntax ```text public event OnSSLConnectionRequestHandler OnSSLConnectionRequest; public delegate void OnSSLConnectionRequestHandler(object sender, TCPServerSSLConnectionRequestEventArgs e); public class TCPServerSSLConnectionRequestEventArgs : EventArgs { public string ConnectionId { get; } public string SupportedCipherSuites { get; } public string SupportedSignatureAlgs { get; } public int CertStoreType { get; set; } public string CertStore { get; set; } public string CertPassword { get; set; } public string CertSubject { get; set; } } ``` ## Remarks This event fires when an SSL connection is requested and [SSLProvider](#sslprovider-property-tcpserver-component) is set to *Internal*. This event provides an opportunity to select an alternative certificate to the connecting client. This event does not fire when [SSLProvider](#sslprovider-property-tcpserver-component) is set to *Platform*. This event allows the component to be configured to use both RSA and ECDSA certificates depending on the connecting client's capabilities. *ConnectionId* is the connection Id of the client requesting the connection. *SupportedCipherSuites* is a comma-separated list of cipher suites that the client supports. *SupportedSignatureAlgs* is a comma-separated list of certificate signature algorithms that the client supports. *CertStoreType* is the store type of the alternate certificate to use for this connection. The component supports both public and private keys in a variety of formats. When the *cstAuto* value is used, the component will automatically determine the type. This field can take one of the following values: ```csharp sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11, @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll", "123456", // PIN "CN=cert_subject"); sftp.SSHUser = "test"; sftp.SSHLogon("myhost", 22); ``` ```csharp certmgr.CertStoreType = CertStoreTypes.cstPKCS11; certmgr.OnCertList += (s, e) => { secKeyBlob = e.CertEncoded; }; certmgr.CertStore = @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll"; certmgr.CertStorePassword = "123456"; // PIN certmgr.ListStoreCertificates(); sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11, secKeyBlob, "123456", "*"); sftp.SSHUser = "test"; sftp.SSHLogon("myhost", 22); ``` | | | | --- | --- | | 0 (cstUser - default) | For Windows, this specifies that the certificate store is a certificate store owned by the current user. NOTE: This store type is not available in Java. | | 1 (cstMachine) | For Windows, this specifies that the certificate store is a machine store. NOTE: This store type is not available in Java. | | 2 (cstPFXFile) | The certificate store is the name of a PFX (PKCS#12) file containing certificates. | | 3 (cstPFXBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in PFX (PKCS#12) format. | | 4 (cstJKSFile) | The certificate store is the name of a Java Key Store (JKS) file containing certificates. NOTE: This store type is only available in Java. | | 5 (cstJKSBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in Java Key Store (JKS) format. NOTE: This store type is only available in Java. | | 6 (cstPEMKeyFile) | The certificate store is the name of a PEM-encoded file that contains a private key and an optional certificate. | | 7 (cstPEMKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains a private key and an optional certificate. | | 8 (cstPublicKeyFile) | The certificate store is the name of a file that contains a PEM- or DER-encoded public key certificate. | | 9 (cstPublicKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains a PEM- or DER-encoded public key certificate. | | 10 (cstSSHPublicKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains an SSH-style public key. | | 11 (cstP7BFile) | The certificate store is the name of a PKCS#7 file containing certificates. | | 12 (cstP7BBlob) | The certificate store is a string (binary) representing a certificate store in PKCS#7 format. | | 13 (cstSSHPublicKeyFile) | The certificate store is the name of a file that contains an SSH-style public key. | | 14 (cstPPKFile) | The certificate store is the name of a file that contains a PPK (PuTTY Private Key). | | 15 (cstPPKBlob) | The certificate store is a string (binary) that contains a PPK (PuTTY Private Key). | | 16 (cstXMLFile) | The certificate store is the name of a file that contains a certificate in XML format. | | 17 (cstXMLBlob) | The certificate store is a string that contains a certificate in XML format. | | 18 (cstJWKFile) | The certificate store is the name of a file that contains a JWK (JSON Web Key). | | 19 (cstJWKBlob) | The certificate store is a string that contains a JWK (JSON Web Key). | | 21 (cstBCFKSFile) | The certificate store is the name of a file that contains a BCFKS (Bouncy Castle FIPS Key Store). NOTE: This store type is only available in Java and .NET. | | 22 (cstBCFKSBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in BCFKS (Bouncy Castle FIPS Key Store) format. NOTE: This store type is only available in Java and .NET. | | 23 (cstPKCS11) | The certificate is present on a physical security key accessible via a PKCS#11 interface. To use a security key, create a new [Certificate](#certificate-type) object and pass cstPKCS11 as the [StoreType](#Certificate_f_StoreType), the full path of the PKCS#11 DLL as the [Store](#Certificate_f_Store), and the PIN as the [StorePassword](#Certificate_f_StorePassword). Code Example. SSH Authentication with Security Key (without CertMgr): Alternatively, collect the necessary data using the [CertMgr](CertMgr.md#CertMgr) component by calling the [ListStoreCertificates](CertMgr.md#CertMgr_m_ListStoreCertificates) method after setting the corresponding properties accordingly. The certificate information returned in the [CertList](CertMgr.md#CertMgr_e_CertList) event's CertEncoded parameter may be saved for later use. When using a certificate obtained with this approach, pass the previously saved security key information as the [Store](#Certificate_f_Store) and set [StorePassword](#Certificate_f_StorePassword) to the PIN. Code Example. SSH Authentication with Security Key (with CertMgr): | | 99 (cstAuto) | The store type is automatically detected from the input data. This setting may be used with both public and private keys and can detect any of the supported formats automatically. | *CertStore* is the store name or location of the alternate certificate to use for this connection. 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). *CertPassword* is the password of the certificate store containing the alternate certificate to use for this connection. *CertSubject* is the subject of the alternate certificate to use for this connection. The special value *** matches any subject and will select the first certificate in the store. 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. # SSLStatus Event ([TCPServer](#tcpserver-component) Component) This event is fired to show the progress of the secure connection. ## Syntax ```text public event OnSSLStatusHandler OnSSLStatus; public delegate void OnSSLStatusHandler(object sender, TCPServerSSLStatusEventArgs e); public class TCPServerSSLStatusEventArgs : EventArgs { public string ConnectionId { get; } public string Message { get; } } ``` ## Remarks The event is fired for informational and logging purposes only. It is used to track the progress of the connection. # Certificate Type This is the digital certificate being used. ## Remarks This type describes the current digital certificate. The certificate may be a public or private key. The fields are used to identify or select certificates. The following fields are available: - [EffectiveDate](#Certificate_f_EffectiveDate) - [ExpirationDate](#Certificate_f_ExpirationDate) - [ExtendedKeyUsage](#Certificate_f_ExtendedKeyUsage) - [Fingerprint](#Certificate_f_Fingerprint) - [FingerprintSHA1](#Certificate_f_FingerprintSHA1) - [FingerprintSHA256](#Certificate_f_FingerprintSHA256) - [Issuer](#Certificate_f_Issuer) - [PrivateKey](#Certificate_f_PrivateKey) - [PrivateKeyAvailable](#Certificate_f_PrivateKeyAvailable) - [PrivateKeyContainer](#Certificate_f_PrivateKeyContainer) - [PublicKey](#Certificate_f_PublicKey) - [PublicKeyAlgorithm](#Certificate_f_PublicKeyAlgorithm) - [PublicKeyLength](#Certificate_f_PublicKeyLength) - [SerialNumber](#Certificate_f_SerialNumber) - [SignatureAlgorithm](#Certificate_f_SignatureAlgorithm) - [Store](#Certificate_f_Store) - [StorePassword](#Certificate_f_StorePassword) - [StoreType](#Certificate_f_StoreType) - [SubjectAltNames](#Certificate_f_SubjectAltNames) - [ThumbprintMD5](#Certificate_f_ThumbprintMD5) - [ThumbprintSHA1](#Certificate_f_ThumbprintSHA1) - [ThumbprintSHA256](#Certificate_f_ThumbprintSHA256) - [Usage](#Certificate_f_Usage) - [UsageFlags](#Certificate_f_UsageFlags) - [Version](#Certificate_f_Version) - [Subject](#Certificate_f_Subject) - [Encoded](#Certificate_f_Encoded) ## Fields **EffectiveDate** *string (read-only)* Default: "" The date on which this certificate becomes valid. Before this date, it is not valid. The date is localized to the system's time zone. The following example illustrates the format of an encoded date: 23-Jan-2000 15:00:00. **ExpirationDate** *string (read-only)* Default: "" The date on which the certificate expires. After this date, the certificate will no longer be valid. The date is localized to the system's time zone. The following example illustrates the format of an encoded date: 23-Jan-2001 15:00:00. **ExtendedKeyUsage** *string (read-only)* Default: "" A comma-delimited list of extended key usage identifiers. These are the same as ASN.1 object identifiers (OIDs). **Fingerprint** *string (read-only)* Default: "" The hex-encoded, 16-byte MD5 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys. The following example illustrates the format: *bc:2a:72:af:fe:58:17:43:7a:5f:ba:5a:7c:90:f7:02* **FingerprintSHA1** *string (read-only)* Default: "" The hex-encoded, 20-byte SHA-1 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys. The following example illustrates the format: *30:7b:fa:38:65:83:ff:da:b4:4e:07:3f:17:b8:a4:ed:80:be:ff:84* **FingerprintSHA256** *string (read-only)* Default: "" The hex-encoded, 32-byte SHA-256 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys. The following example illustrates the format: *6a:80:5c:33:a9:43:ea:b0:96:12:8a:64:96:30:ef:4a:8a:96:86:ce:f4:c7:be:10:24:8e:2b:60:9e:f3:59:53* **Issuer** *string (read-only)* Default: "" The issuer of the certificate. This field contains a string representation of the name of the issuing authority for the certificate. **PrivateKey** *string (read-only)* Default: "" The private key of the certificate (if available). The key is provided as PEM/Base64-encoded data. NOTE: The [PrivateKey](#Certificate_f_PrivateKey) may be available but not exportable. In this case, [PrivateKey](#Certificate_f_PrivateKey) returns an empty string. **PrivateKeyAvailable** *bool (read-only)* Default: False Whether a [PrivateKey](#Certificate_f_PrivateKey) is available for the selected certificate. If [PrivateKeyAvailable](#Certificate_f_PrivateKeyAvailable) is True, the certificate may be used for authentication purposes (e.g., server authentication). **PrivateKeyContainer** *string (read-only)* Default: "" The name of the [PrivateKey](#Certificate_f_PrivateKey) container for the certificate (if available). This functionality is available only on Windows platforms. **PublicKey** *string (read-only)* Default: "" The public key of the certificate. The key is provided as PEM/Base64-encoded data. **PublicKeyAlgorithm** *string (read-only)* Default: "" The textual description of the certificate's public key algorithm. The property contains either the name of the algorithm (e.g., "RSA" or "RSA_DH") or an object identifier (OID) string representing the algorithm. **PublicKeyLength** *int (read-only)* Default: 0 The length of the certificate's public key (in bits). Common values are 512, 1024, and 2048. **SerialNumber** *string (read-only)* Default: "" The serial number of the certificate encoded as a string. The number is encoded as a series of hexadecimal digits, with each pair representing a byte of the serial number. **SignatureAlgorithm** *string (read-only)* Default: "" The text description of the certificate's signature algorithm. The property contains either the name of the algorithm (e.g., "RSA" or "RSA_MD5RSA") or an object identifier (OID) string representing the algorithm. **Store** *string* Default: "MY" The name of the certificate store for the client certificate. The [StoreType](#Certificate_f_StoreType) field denotes the type of the certificate store specified by [Store](#Certificate_f_Store). If the store is password-protected, specify the password in [StorePassword](#Certificate_f_StorePassword). [Store](#Certificate_f_Store) is used in conjunction with the [Subject](#Certificate_f_Subject) field to specify client certificates. If [Store](#Certificate_f_Store) has a value, and [Subject](#Certificate_f_Subject) or [Encoded](#Certificate_f_Encoded) is set, a search for a certificate is initiated. Please see the [Subject](#Certificate_f_Subject) field 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). **StoreB** *byte []* Default: "MY" The name of the certificate store for the client certificate. The [StoreType](#Certificate_f_StoreType) field denotes the type of the certificate store specified by [Store](#Certificate_f_Store). If the store is password-protected, specify the password in [StorePassword](#Certificate_f_StorePassword). [Store](#Certificate_f_Store) is used in conjunction with the [Subject](#Certificate_f_Subject) field to specify client certificates. If [Store](#Certificate_f_Store) has a value, and [Subject](#Certificate_f_Subject) or [Encoded](#Certificate_f_Encoded) is set, a search for a certificate is initiated. Please see the [Subject](#Certificate_f_Subject) field 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). **StorePassword** *string* Default: "" If the type of certificate store requires a password, this field is used to specify the password needed to open the certificate store. **StoreType** *CertStoreTypes* Default: 0 The type of certificate store for this certificate. The component supports both public and private keys in a variety of formats. When the *cstAuto* value is used, the component will automatically determine the type. This field can take one of the following values: ```csharp sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11, @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll", "123456", // PIN "CN=cert_subject"); sftp.SSHUser = "test"; sftp.SSHLogon("myhost", 22); ``` ```csharp certmgr.CertStoreType = CertStoreTypes.cstPKCS11; certmgr.OnCertList += (s, e) => { secKeyBlob = e.CertEncoded; }; certmgr.CertStore = @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll"; certmgr.CertStorePassword = "123456"; // PIN certmgr.ListStoreCertificates(); sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11, secKeyBlob, "123456", "*"); sftp.SSHUser = "test"; sftp.SSHLogon("myhost", 22); ``` | | | | --- | --- | | 0 (cstUser - default) | For Windows, this specifies that the certificate store is a certificate store owned by the current user. NOTE: This store type is not available in Java. | | 1 (cstMachine) | For Windows, this specifies that the certificate store is a machine store. NOTE: This store type is not available in Java. | | 2 (cstPFXFile) | The certificate store is the name of a PFX (PKCS#12) file containing certificates. | | 3 (cstPFXBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in PFX (PKCS#12) format. | | 4 (cstJKSFile) | The certificate store is the name of a Java Key Store (JKS) file containing certificates. NOTE: This store type is only available in Java. | | 5 (cstJKSBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in Java Key Store (JKS) format. NOTE: This store type is only available in Java. | | 6 (cstPEMKeyFile) | The certificate store is the name of a PEM-encoded file that contains a private key and an optional certificate. | | 7 (cstPEMKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains a private key and an optional certificate. | | 8 (cstPublicKeyFile) | The certificate store is the name of a file that contains a PEM- or DER-encoded public key certificate. | | 9 (cstPublicKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains a PEM- or DER-encoded public key certificate. | | 10 (cstSSHPublicKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains an SSH-style public key. | | 11 (cstP7BFile) | The certificate store is the name of a PKCS#7 file containing certificates. | | 12 (cstP7BBlob) | The certificate store is a string (binary) representing a certificate store in PKCS#7 format. | | 13 (cstSSHPublicKeyFile) | The certificate store is the name of a file that contains an SSH-style public key. | | 14 (cstPPKFile) | The certificate store is the name of a file that contains a PPK (PuTTY Private Key). | | 15 (cstPPKBlob) | The certificate store is a string (binary) that contains a PPK (PuTTY Private Key). | | 16 (cstXMLFile) | The certificate store is the name of a file that contains a certificate in XML format. | | 17 (cstXMLBlob) | The certificate store is a string that contains a certificate in XML format. | | 18 (cstJWKFile) | The certificate store is the name of a file that contains a JWK (JSON Web Key). | | 19 (cstJWKBlob) | The certificate store is a string that contains a JWK (JSON Web Key). | | 21 (cstBCFKSFile) | The certificate store is the name of a file that contains a BCFKS (Bouncy Castle FIPS Key Store). NOTE: This store type is only available in Java and .NET. | | 22 (cstBCFKSBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in BCFKS (Bouncy Castle FIPS Key Store) format. NOTE: This store type is only available in Java and .NET. | | 23 (cstPKCS11) | The certificate is present on a physical security key accessible via a PKCS#11 interface. To use a security key, create a new [Certificate](#certificate-type) object and pass cstPKCS11 as the [StoreType](#Certificate_f_StoreType), the full path of the PKCS#11 DLL as the [Store](#Certificate_f_Store), and the PIN as the [StorePassword](#Certificate_f_StorePassword). Code Example. SSH Authentication with Security Key (without CertMgr): Alternatively, collect the necessary data using the [CertMgr](CertMgr.md#CertMgr) component by calling the [ListStoreCertificates](CertMgr.md#CertMgr_m_ListStoreCertificates) method after setting the corresponding properties accordingly. The certificate information returned in the [CertList](CertMgr.md#CertMgr_e_CertList) event's CertEncoded parameter may be saved for later use. When using a certificate obtained with this approach, pass the previously saved security key information as the [Store](#Certificate_f_Store) and set [StorePassword](#Certificate_f_StorePassword) to the PIN. Code Example. SSH Authentication with Security Key (with CertMgr): | | 99 (cstAuto) | The store type is automatically detected from the input data. This setting may be used with both public and private keys and can detect any of the supported formats automatically. | **SubjectAltNames** *string (read-only)* Default: "" Comma-separated lists of alternative subject names for the certificate. **ThumbprintMD5** *string (read-only)* Default: "" The MD5 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed. **ThumbprintSHA1** *string (read-only)* Default: "" The SHA-1 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed. **ThumbprintSHA256** *string (read-only)* Default: "" The SHA-256 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed. **Usage** *string (read-only)* Default: "" The text description of [UsageFlags](#Certificate_f_UsageFlags). This value will be one or more of the following strings and will be separated by commas: - Digital Signature - Non-Repudiation - Key Encipherment - Data Encipherment - Key Agreement - Certificate Signing - CRL Signing - Encipher Only If the provider is OpenSSL, the value is a comma-separated list of X.509 certificate extension names. **UsageFlags** *int (read-only)* Default: 0 The flags that show intended use for the certificate. The value of [UsageFlags](#Certificate_f_UsageFlags) is a combination of the following flags: | | | | --- | --- | | 0x80 | Digital Signature | | 0x40 | Non-Repudiation | | 0x20 | Key Encipherment | | 0x10 | Data Encipherment | | 0x08 | Key Agreement | | 0x04 | Certificate Signing | | 0x02 | CRL Signing | | 0x01 | Encipher Only | Please see the [Usage](#Certificate_f_Usage) field for a text representation of [UsageFlags](#Certificate_f_UsageFlags). This functionality currently is not available when the provider is OpenSSL. **Version** *string (read-only)* Default: "" The certificate's version number. The possible values are the strings "V1", "V2", and "V3". **Subject** *string* Default: "" The subject of the certificate used for client authentication. This field will be populated with the full subject of the loaded certificate. When loading a certificate, the subject is used to locate the certificate in the store. If an exact match is not found, the store is searched for subjects containing the value of the property. If a match is still not found, the property is set to an empty string, and no certificate is selected. The special value "*" picks a random certificate in the certificate store. 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. **Encoded** *string* Default: "" The certificate (PEM/Base64 encoded). This field is used to assign a specific certificate. The [Store](#Certificate_f_Store) and [Subject](#Certificate_f_Subject) fields also may be used to specify a certificate. When [Encoded](#Certificate_f_Encoded) is set, a search is initiated in the current [Store](#Certificate_f_Store) for the private key of the certificate. If the key is found, [Subject](#Certificate_f_Subject) is updated to reflect the full subject of the selected certificate; otherwise, [Subject](#Certificate_f_Subject) is set to an empty string. **EncodedB** *byte []* Default: "" The certificate (PEM/Base64 encoded). This field is used to assign a specific certificate. The [Store](#Certificate_f_Store) and [Subject](#Certificate_f_Subject) fields also may be used to specify a certificate. When [Encoded](#Certificate_f_Encoded) is set, a search is initiated in the current [Store](#Certificate_f_Store) for the private key of the certificate. If the key is found, [Subject](#Certificate_f_Subject) is updated to reflect the full subject of the selected certificate; otherwise, [Subject](#Certificate_f_Subject) is set to an empty string. ## Constructors ```text public Certificate(); ``` Creates a instance whose properties can be set. ```text public Certificate(string certificateFile); ``` Opens * CertificateFile * and reads out the contents as an X.509 public key. ```text public Certificate(byte[] encoded); ``` Parses * Encoded * as an X.509 public key. ```text public Certificate(CertStoreTypes storeType, string store, string storePassword, string subject); ``` * StoreType * identifies the type of certificate store to use. See for descriptions of the different certificate stores. * Store * is a file containing the certificate store. * StorePassword * is the password used to protect the store. After the store has been successfully opened, the component will attempt to find the certificate identified by * Subject * . This can be either a complete or a substring match of the X.509 certificate's subject Distinguished Name (DN). The * Subject * parameter can also take an MD5, SHA-1, or SHA-256 thumbprint of the certificate to load in a "Thumbprint=value" format. ```text public Certificate(CertStoreTypes storeType, string store, string storePassword, string subject, string configurationString); ``` * StoreType * identifies the type of certificate store to use. See for descriptions of the different certificate stores. * Store * is a file containing the certificate store. * StorePassword * is the password used to protect the store. * ConfigurationString * is a newline-separated list of name-value pairs that may be used to modify the default behavior. Possible values include "PersistPFXKey", which shows whether or not the PFX key is persisted after performing operations with the private key. This correlates to the PKCS12_NO_PERSIST_KEY CryptoAPI option. The default value is True (the key is persisted). "Thumbprint" - an MD5, SHA-1, or SHA-256 thumbprint of the certificate to load. When specified, this value is used to select the certificate in the store. This is applicable to the * cstUser * , * cstMachine * , * cstPublicKeyFile * , and * cstPFXFile * store types. "UseInternalSecurityAPI" shows whether the platform (default) or the internal security API is used when performing certificate-related operations. After the store has been successfully opened, the component will attempt to find the certificate identified by * Subject * . This can be either a complete or a substring match of the X.509 certificate's subject Distinguished Name (DN). The * Subject * parameter can also take an MD5, SHA-1, or SHA-256 thumbprint of the certificate to load in a "Thumbprint=value" format. ```text public Certificate(CertStoreTypes storeType, string store, string storePassword, byte[] encoded); ``` * StoreType * identifies the type of certificate store to use. See for descriptions of the different certificate stores. * Store * is a file containing the certificate store. * StorePassword * is the password used to protect the store. After the store has been successfully opened, the component will load * Encoded * as an X.509 certificate and search the opened store for a corresponding private key. ```text public Certificate(CertStoreTypes storeType, byte[] store, string storePassword, string subject); ``` * StoreType * identifies the type of certificate store to use. See for descriptions of the different certificate stores. * Store * is a byte array containing the certificate data. * StorePassword * is the password used to protect the store. After the store has been successfully opened, the component will attempt to find the certificate identified by * Subject * . This can be either a complete or a substring match of the X.509 certificate's subject Distinguished Name (DN). The * Subject * parameter can also take an MD5, SHA-1, or SHA-256 thumbprint of the certificate to load in a "Thumbprint=value" format. ```text public Certificate(CertStoreTypes storeType, byte[] store, string storePassword, string subject, string configurationString); ``` * StoreType * identifies the type of certificate store to use. See for descriptions of the different certificate stores. * Store * is a byte array containing the certificate data. * StorePassword * is the password used to protect the store. After the store has been successfully opened, the component will attempt to find the certificate identified by * Subject * . This can be either a complete or a substring match of the X.509 certificate's subject Distinguished Name (DN). The * Subject * parameter can also take an MD5, SHA-1, or SHA-256 thumbprint of the certificate to load in a "Thumbprint=value" format. ```text public Certificate(CertStoreTypes storeType, byte[] store, string storePassword, byte[] encoded); ``` * StoreType * identifies the type of certificate store to use. See for descriptions of the different certificate stores. * Store * is a byte array containing the certificate data. * StorePassword * is the password used to protect the store. After the store has been successfully opened, the component will load * Encoded * as an X.509 certificate and search the opened store for a corresponding private key. # Connection Type This is a currently connected client. ## Remarks This type describes the connection of a client that is currently connected to the component. You may use the different fields of this type to manage the connection. The following fields are available: - [AcceptData](#Connection_f_AcceptData) - [BytesSent](#Connection_f_BytesSent) - [Connected](#Connection_f_Connected) - [ConnectionId](#Connection_f_ConnectionId) - [EOL](#Connection_f_EOL) - [IdleTimeout](#Connection_f_IdleTimeout) - [LocalAddress](#Connection_f_LocalAddress) - [MaxLineLength](#Connection_f_MaxLineLength) - [ReadyToSend](#Connection_f_ReadyToSend) - [RecordLength](#Connection_f_RecordLength) - [RemoteHost](#Connection_f_RemoteHost) - [RemotePort](#Connection_f_RemotePort) - [SingleLineMode](#Connection_f_SingleLineMode) - [Timeout](#Connection_f_Timeout) - [UserData](#Connection_f_UserData) ## Fields **AcceptData** *bool (read-only)* Default: True This field indicates whether data reception is currently enabled. When *false*, data reception is disabled and the DataIn event will not fire for the connection. Use the PauseData and ProcessData methods to pause and resume data reception. **BytesSent** *int (read-only)* Default: 0 This field shows how many bytes were sent after calling Send or SendBytes. Please see Send or SendBytes for more information. NOTE: This field will always return 0 when the component is operating in the synchronous mode (i.e., the [Timeout](#Connection_f_Timeout) property is set to a positive value). **Connected** *bool (read-only)* Default: False This field indicates the status of individual connections. When *true*, the connection is established. Use the Disconnect method to disconnect an existing connection. **ConnectionId** *string (read-only)* Default: "" This field contains an identifier generated by the component to identify each connection. This identifier is unique to this connection. **EOL** *string* Default: "" The [EOL](#Connection_f_EOL) field is used to define boundaries in the input stream using the value of the field. The [EOL](#Connection_f_EOL) field is especially useful with ASCII files. By setting it to CRLF (*"\r\n"*) , the incoming ASCII text stream can be split into lines. In this case, one event is fired for each line received (as well as in packet boundaries). The CRLF (*"\r\n"*) . bytes are discarded. The [EOL](#Connection_f_EOL) field is a binary string. This means that it can be more than one byte long, and it can contain NULL bytes. **EOLB** *byte []* Default: "" The [EOL](#Connection_f_EOL) field is used to define boundaries in the input stream using the value of the field. The [EOL](#Connection_f_EOL) field is especially useful with ASCII files. By setting it to CRLF (*"\r\n"*) , the incoming ASCII text stream can be split into lines. In this case, one event is fired for each line received (as well as in packet boundaries). The CRLF (*"\r\n"*) . bytes are discarded. The [EOL](#Connection_f_EOL) field is a binary string. This means that it can be more than one byte long, and it can contain NULL bytes. **IdleTimeout** *int* Default: 0 This field contains the idle timeout for this connection. This field is similar to DefaultIdleTimeout but may be set on a per-connection basis to override DefaultIdleTimeout. This field specifies the idle timeout (in seconds) for the connected client. When set to a positive value, the component will disconnect idle clients after the specified timeout. This applies only to clients that have not sent to received data within the specified number of seconds. If set to 0 (default), no idle timeout is applied. NOTE: DoEvents must be called for the component to check existing connections. **LocalAddress** *string (read-only)* Default: "" This field shows the IP address of the interface through which the connection is passing. [LocalAddress](#Connection_f_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. **MaxLineLength** *int* Default: 2048 This field is the size of an internal buffer that holds received data while waiting for an [EOL](#Connection_f_EOL) string. If an [EOL](#Connection_f_EOL) string is found in the input stream before [MaxLineLength](#Connection_f_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](#Connection_f_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](#Connection_f_MaxLineLength) is 256 bytes. The default value is 2048 bytes. **ReadyToSend** *bool (read-only)* Default: False This field indicates whether the component is ready to send data. This is *true* after a client connects but will become *false* after a failed call to Send or SendBytes. After a failed call to Send or SendBytes, the ReadyToSend event will fire and this field will be *true* when data can be sent again. **RecordLength** *int (read-only)* Default: 0 This field holds the current record length set by ChangeRecordLength. When this value is a positive number, the component will accumulate data until [RecordLength](#Connection_f_RecordLength) is reached and only then will fire the DataIn event with the data of length [RecordLength](#Connection_f_RecordLength). This allows data to be received as records of known length. This value can be changed at any time by calling ChangeRecordLength, including within the DataIn event. A value of 0 (default) means this setting is not used. **RemoteHost** *string (read-only)* Default: "" 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. **RemotePort** *int (read-only)* Default: 0 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. **SingleLineMode** *bool* Default: False This field shows the special mode for line-oriented protocols. When SingleLineMode is True, the component treats the incoming data stream as lines separated by carriage return (CR), line feed (LF), or CRLF. The EOL property is ignored. **Timeout** *int* Default: 0 This field specifies a timeout for the component. This field defines the timeout when sending data. When SSLEnabled is False, a value of 0 means data will be sent asynchronously and a positive value means data will be sent synchronously. When SSLEnabled is True, all data is sent synchronously regardless of the [Timeout](#Connection_f_Timeout) value. Please see the following notes for details. **Plaintext** If the [Timeout](#Connection_f_Timeout) field is set to 0, all operations return immediately, potentially failing with a *WOULDBLOCK* error if data cannot be sent immediately. If [Timeout](#Connection_f_Timeout) is set to a positive value, data is sent in a blocking manner and the component will wait for the operation to complete before returning control. The component will handle any potential *WOULDBLOCK* errors internally and automatically retry the operation for a maximum of [Timeout](#Connection_f_Timeout) seconds. **SSL** If the [Timeout](#Connection_f_Timeout) field is set to 0, all operations will run uninterrupted until successful completion or an error condition is encountered. If [Timeout](#Connection_f_Timeout) is set to a positive value, the component will wait for the operation to complete before returning control. **Additional Notes** The component will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not freeze and remains responsive. If Timeout expires, and the operation is not yet complete, the component throws an exception. NOTE: By default, all timeouts are *inactivity timeouts*, that is, the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received. The default value for the [Timeout](#Connection_f_Timeout) field is 0 (asynchronous for plaintext, synchronous for SSL). **UserData** *string* Default: "" The [UserData](#Connection_f_UserData) field holds connection-specific user-specified data. User-specified data may be set or retrieved at any point while the connection is valid. This provides a simple way to associate arbitrary data with a specific connection. **UserDataB** *byte []* Default: "" The [UserData](#Connection_f_UserData) field holds connection-specific user-specified data. User-specified data may be set or retrieved at any point while the connection is valid. This provides a simple way to associate arbitrary data with a specific connection. ## Constructors ```text public Connection(); ``` # Config Settings ([TCPServer](#tcpserver-component) Component) The component 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 component, access to these *internal properties* is provided through the [Config](#config-method-tcpserver-component) method. ### TCPServer Config Settings **AllowedClients**: A comma-separated list of host names or IP addresses that can access the component.This configuration setting defines a comma-separated list of host names or IPv4 addresses that may access the component. The wildcard character "*" is supported. The default value is "*" and all connections are accepted. When a client connects, the client's address is checked against the list defined here. If there is no match, the [ConnectionRequest](#connectionrequest-event-tcpserver-component) event fires with an *Accept* value set to *false*. If no action is taken within the [ConnectionRequest](#connectionrequest-event-tcpserver-component) event, the client will be disconnected. **BindExclusively**: Whether or not the component considers a local port reserved for exclusive use.If this is *true* (default), the component will bind to the local port with the ExclusiveAddressUse option set, meaning that nothing else can bind to the same port. Also the component will not be able to bind to local ports that are already in use by some other instance, and attempts to do so will result in failure. **BlockedClients**: A comma-separated list of host names or IP addresses that cannot access the component.This configuration setting defines a comma-separated list of host names or IPv4 addresses that cannot access the component.The default value is "" and all connections are accepted. When a client connects, the client's address is checked against the list defined here. If there is a match, the [ConnectionRequest](#connectionrequest-event-tcpserver-component) event fires with an *Accept* value set to *false*. If no action is taken within the [ConnectionRequest](#connectionrequest-event-tcpserver-component) event, the client will not be connected. **CloseStreamAfterTransfer**: If true, the component will close the upload or download stream after the transfer.This configuration setting determines whether the input or output stream is closed after the transfer completes. When set to True (default), all streams will be closed after a transfer is completed. To keep streams open after the transfer of data, set this to False. The default value is True. **DefaultConnectionTimeout**: The inactivity timeout applied to the SSL handshake.This configuration setting specifies the inactivity (in seconds) to apply to incoming Secure Sockets Layer (SSL) connections. When set to a positive value, if the other end is unresponsive for the specified number of seconds, the connection will timeout. This is not applicable to the entire handshake. It is applicable only to the inactivity of the connecting client during the handshake if a response is expected and none is received within the timeout window. The default value is 0, and no connection-specific timeout is applied. NOTE: This is applicable only to incoming SSL connections. This should be set only if there is a specific reason to do so. **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. Increasing the value of the [InBufferSize](#InBufferSize) setting can provide significant improvements in performance in some cases. Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated, the [InBufferSize](#InBufferSize) reverts to its defined size. The same thing will happen if you attempt to make it too large or too small. [InBufferSize](#InBufferSize) is shared among incoming connections. When the setting is set, the corresponding value is set for incoming connections as they are accepted. Existing connections are not modified. **KeepAliveInterval**: The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.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 setting specifies the interval at which the successive keep-alive packets are sent in milliseconds. If this value is not specified here, the system default is 1 second. This setting is applicable to all connections. NOTE: This value is not applicable in macOS. **KeepAliveTime**: The inactivity time in milliseconds before a TCP keep-alive packet is sent.By default, the operating system will determine the time a connection is idle before a TCP keep-alive packet is sent. If this value is not specified here, the system default is 2 hours. In many cases, a shorter interval is more useful. Set this value to the desired interval in milliseconds. This setting is applicable to all connections. **MaxConnections**: The maximum number of connections available. This is the maximum number of connections available. This setting must be set before [Listening](#listening-property-tcpserver-component) is set to *true*, and once set, it can no longer be changed for the current instance of the component. The maximum value for this setting is 100,000 connections. Use this setting with caution. Extremely large values may affect performance. **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. Increasing the value of the [OutBufferSize](#OutBufferSize) setting can provide significant improvements in performance in some cases. Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated the [OutBufferSize](#OutBufferSize) reverts to its defined size. The same thing will happen if you attempt to make it too large or too small. [OutBufferSize](#OutBufferSize) is shared among incoming connections. When the setting is set, the corresponding value is set for incoming connections as they are accepted. Existing connections are not modified. **PreferredDHGroupBits**: Size of the Diffie-Hellman group, in bits.This configuration setting specifies the key length used by the Diffie-Hellman key algorithm. The default value is *2048* (bits). **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. **UseBackgroundThread**: Whether threads created by the component are background threads.If set to *true*, when the component creates a thread, the thread's IsBackground property will be explicitly set to *true*. By default, this setting is *false*. **UseIPv6**: Whether to use IPv6.When set to 0 (default), the component will use IPv4 exclusively. When set to 1, the component will use IPv6 exclusively. When set to 2, the component will listen for both IPv4 and IPv6 connections. If IPv6 is not available on the system, only IPv4 will be used. The default value is 0. Possible values are as follows: | | | | --- | --- | | 0 | IPv4 Only | | 1 | IPv6 Only | | 2 | IPv6 and IPv4 | ### SSL Config Settings **CACertFilePaths**: The paths to CA certificate files when using Mono on Unix/Linux.This configuration setting specifies the paths on disk to certificate authority (CA) certificate files when using Mono on Unix/Linux. It is not applicable in any other circumstances. The value is formatted as a list of paths separated by semicolons. The component will check for the existence of each file in the order specified. When a file is found, the CA certificates within the file will be loaded and used to determine the validity of server or client certificates. The default value is as follows: */etc/ssl/ca-bundle.pem;/etc/pki/tls/certs/ca-bundle.crt;/etc/ssl/certs/ca-certificates.crt;/etc/pki/tls/cacert.pem* **LogSSLPackets**: Controls whether SSL packets are logged when using the internal security API.When [SSLProvider](#sslprovider-property-tcpserver-component) 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-tcpserver-component) event, which will fire each time an SSL packet is sent or received. Enabling this configuration setting has no effect if [SSLProvider](#sslprovider-property-tcpserver-component) is set to *Platform*. **ReuseSSLSession**: Determines if the SSL session is reused. If set to True, the component 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 component is the same. **SSLCACerts**: A newline separated list of CA certificates to be included when performing an SSL handshake.When [SSLProvider](#sslprovider-property-tcpserver-component) is set to *Internal*, this configuration setting specifies one or more CA certificates to be included with the [SSLCert](#sslcert-property-tcpserver-component) 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 component will check the Certificate Revocation List (CRL) specified by the server certificate. If set to 1 or 2, the component will first obtain the list of CRL URLs from the server certificate's CRL distribution points extension. The component 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 component throws an exception. When set to 0 (default), the CRL check will not be performed by the component. 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 component will use OCSP to check the validity of the server certificate. If set to 1 or 2, the component will first obtain the Online Certificate Status Protocol (OCSP) URL from the server certificate's OCSP extension. The component 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 component throws an exception. When set to 0 (default), the component 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-tcpserver-component) 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](#sslauthenticateclients-property-tcpserver-component) 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 component 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-tcpserver-component) 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-tcpserver-component) 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-tcpserver-component) 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-tcpserver-component) 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 component will first try to use the platform TLS 1.3 implementation when the [SSLProvider](#sslprovider-property-tcpserver-component) 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-tcpserver-component) 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 component when the [SSLProvider](#sslprovider-property-tcpserver-component) 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-tcpserver-component) 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-tcpserver-component) 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. Note: When [SSLProvider](#sslprovider-property-tcpserver-component) is set to *Internal* this value is automatically set to *true*. This is needed for proper validation when using the internal provider. **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 component 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 component will only append, it will not overwrite previous values. NOTE: This configuration setting is applicable only when [SSLProvider](#sslprovider-property-tcpserver-component) 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 in Java or 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-tcpserver-component) is set to *Internal* and [SSLEnabledProtocols](#SSLEnabledProtocols) is set to allow TLS 1.2. When specified the component 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 component throws an exception. 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-tcpserver-component) 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 ### Base Config Settings **BuildInfo**: Information about the product's build.When queried, this setting will return a string containing information about the product's build. **GUIAvailable**: Whether or not a message loop is available for processing events.In a GUI-based application, long-running blocking operations may cause the application to stop responding to input until the operation returns. The component will attempt to discover whether or not the application has a message loop and, if one is discovered, it will process events in that message loop during any such blocking operation. In some non-GUI applications, an invalid message loop may be discovered that will result in errant behavior. In these cases, setting [GUIAvailable](#GUIAvailable) to *false* will ensure that the component does not attempt to process external events. **LicenseInfo**: Information about the current license.When queried, this setting will return a string containing information about the license this instance of a component is using. It will return the following information: - Product: The product the license is for. - Product Key: The key the license was generated from. - License Source: Where the license was found (e.g., RuntimeLicense, License File). - License Type: The type of license installed (e.g., Royalty Free, Single Server). - Last Valid Build: The last valid build number for which the license will work. **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 component will use the system security libraries by default to perform cryptographic functions where applicable. In this case, calls to unmanaged code will be made. In certain environments, this is not desirable. To use a completely managed security implementation, set this setting to *true*. Setting this configuration setting to *true* tells the component to use the internal implementation instead of using the system security libraries. On Windows, this setting is set to *false* by default. On Linux/macOS, this setting is set to *true* by default. NOTE: This setting is static. The value set is applicable to all components used in the application. When this value is set, the product's system dynamic link library (DLL) is no longer required as a reference, as all unmanaged code is stored in that file. # Trappable Errors ([TCPServer](#tcpserver-component) Component) ### TCPServer Errors | | | | --- | --- | | 100 | You cannot change the RemotePort at this time. A connection is in progress. | | 101 | You cannot change the RemoteHost at this time. A connection is in progress. | | 102 | The RemoteHost address is invalid (0.0.0.0). | | 104 | TCPServer is already listening. | | 106 | Cannot change [LocalPort](#localport-property-tcpserver-component) when TCPServer is listening. | | 107 | Cannot change [LocalHost](#localhost-property-tcpserver-component) when TCPServer is listening. | | 108 | Cannot change [MaxConnections](#MaxConnections) when TCPServer is listening. | | 112 | You cannot change [MaxLineLength](#MaxLineLength) at this time. A connection is in progress. | | 116 | RemotePort cannot be zero. Please specify a valid service port number. | | 126 | Invalid ConnectionId. | | 135 | Operation would block. | ### SSL Errors | | | | --- | --- | | 270 | Cannot load specified security library. | | 271 | Cannot open certificate store. | | 272 | Cannot find specified certificate. | | 273 | Cannot acquire security credentials. | | 274 | Cannot find certificate chain. | | 275 | Cannot verify certificate chain. | | 276 | Error during handshake. | | 280 | Error verifying certificate. | | 281 | Could not find client certificate. | | 282 | Could not find server certificate. | | 283 | Error encrypting data. | | 284 | Error decrypting data. | ### TCP/IP Errors | | | | --- | --- | | 10004 | [10004] Interrupted system call. | | 10009 | [10009] Bad file number. | | 10013 | [10013] Access denied. | | 10014 | [10014] Bad address. | | 10022 | [10022] Invalid argument. | | 10024 | [10024] Too many open files. | | 10035 | [10035] Operation would block. | | 10036 | [10036] Operation now in progress. | | 10037 | [10037] Operation already in progress. | | 10038 | [10038] Socket operation on nonsocket. | | 10039 | [10039] Destination address required. | | 10040 | [10040] Message is too long. | | 10041 | [10041] Protocol wrong type for socket. | | 10042 | [10042] Bad protocol option. | | 10043 | [10043] Protocol is not supported. | | 10044 | [10044] Socket type is not supported. | | 10045 | [10045] Operation is not supported on socket. | | 10046 | [10046] Protocol family is not supported. | | 10047 | [10047] Address family is not supported by protocol family. | | 10048 | [10048] Address already in use. | | 10049 | [10049] Cannot assign requested address. | | 10050 | [10050] Network is down. | | 10051 | [10051] Network is unreachable. | | 10052 | [10052] Net dropped connection or reset. | | 10053 | [10053] Software caused connection abort. | | 10054 | [10054] Connection reset by peer. | | 10055 | [10055] No buffer space available. | | 10056 | [10056] Socket is already connected. | | 10057 | [10057] Socket is not connected. | | 10058 | [10058] Cannot send after socket shutdown. | | 10059 | [10059] Too many references, cannot splice. | | 10060 | [10060] Connection timed out. | | 10061 | [10061] Connection refused. | | 10062 | [10062] Too many levels of symbolic links. | | 10063 | [10063] File name is too long. | | 10064 | [10064] Host is down. | | 10065 | [10065] No route to host. | | 10066 | [10066] Directory is not empty | | 10067 | [10067] Too many processes. | | 10068 | [10068] Too many users. | | 10069 | [10069] Disc Quota Exceeded. | | 10070 | [10070] Stale NFS file handle. | | 10071 | [10071] Too many levels of remote in path. | | 10091 | [10091] Network subsystem is unavailable. | | 10092 | [10092] WINSOCK DLL Version out of range. | | 10093 | [10093] Winsock is not loaded yet. | | 11001 | [11001] Host not found. | | 11002 | [11002] Nonauthoritative 'Host not found' (try again or check DNS setup). | | 11003 | [11003] Nonrecoverable errors: FORMERR, REFUSED, NOTIMP. | | 11004 | [11004] Valid name, no data record (check DNS setup). |