TCPServer Class

Properties   Methods   Events   Config Settings   Errors  

The TCPServer Class is a generic Transmission Control Protocol (TCP) server class based on an asynchronous, event-driven architecture. It is designed to balance the load between connections for a fast, powerful server.

Syntax

class ipworks.TCPServer

Remarks

The TCPServer Class supports both plaintext and Secure Sockets Layer/Transport Layer Security (SSL/TLS) connections. When connecting over SSL/TLS the on_ssl_server_authentication event allows you to check the server identity and other security attributes. The on_ssl_status event provides information about the SSL handshake. Additional SSL related settings are also supported via the config 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 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 class has a minimum of properties, and six events: on_connection_request, on_connected, on_data_in, on_disconnected, on_ready_to_send, and on_error.

TCPServer can start to listen on a port by setting the listening property to True. When a remote host asks for a connection, the on_connection_request 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 data_to_send property. The address and port of the incoming connection can be found by querying the remote_host and remote_port properties.

Note: Server components are designed to process events as they occur. To ensure that events are processed in a timely manner, do_events should be called in a loop after the server is started.

Property List


The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

connection_backlogThis property includes the maximum number of pending connections maintained by the Transmission Control Protocol (TCP)/IP subsystem.
connection_countThe number of records in the arrays.
accept_dataSetting this property to false temporarily disables data reception (and the DataIn event) for the connection.
bytes_sentThis property shows how many bytes were sent after the last assignment to DataToSend .
connectedThis property is used to disconnect individual connections or to show their status.
connection_idThis property contains an identifier generated by the class to identify each connection.
data_to_sendThis property contains a string of data to be sent to the remote host.
eolThe EOL property is used to define boundaries in the input stream using the value of the property.
idle_timeoutThis property contains the idle timeout for this connection.
local_addressThis property shows the IP address of the interface through which the connection is passing.
ready_to_sendThis indicates whether the class is ready to send data.
record_lengthIf set to a positive value, this setting defines the length of the data records to be received.
remote_hostThis property shows the IP address of the remote host through which the connection is coming.
remote_portThis property shows the Transmission Control Protocol (TCP) port on the remote host through which the connection is coming.
single_line_modeThis property shows the special mode for line-oriented protocols.
timeoutThis property specifies a timeout for the class.
user_dataThe UserData property holds connection-specific user-specified data.
default_eolThis property includes a default end-of-line (EOL) value to be used by incoming connections.
default_idle_timeoutThis property includes the default idle timeout for inactive clients.
default_max_line_lengthThe property includes the default maximum line length value for inbound connections.
default_single_line_modeThis property tells the class whether or not to treat new connections as line oriented.
default_timeoutThis property includes an initial timeout value to be used by incoming connections.
keep_aliveWhen True, KEEPALIVE packets are enabled (for long connections).
lingerWhen set to True, connections are terminated gracefully.
listeningIf set to True, the class accepts incoming connections on LocalPort.
local_hostThe name of the local host or user-assigned IP interface through which connections are initiated or accepted.
local_portThis property includes the Transmission Control Protocol (TCP) port in the local host where the class listens.
ssl_authenticate_clientsIf set to True, the server asks the client(s) for a certificate.
ssl_cert_encodedThis is the certificate (PEM/base64 encoded).
ssl_cert_storeThis is the name of the certificate store for the client certificate.
ssl_cert_store_passwordIf the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.
ssl_cert_store_typeThis is the type of certificate store for this certificate.
ssl_cert_subjectThis is the subject of the certificate used for client authentication.
ssl_enabledWhether TLS/SSL is enabled.
ssl_providerThis specifies the SSL/TLS implementation to use.
ssl_start_modeDetermines how the class starts the SSL negotiation.

Method List


The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

change_record_lengthThis method changes the length of received data records.
configSets or retrieves a configuration setting.
disconnectThis method disconnects the specified client.
do_eventsProcesses events from the internal message queue.
interruptThis method interrupts a synchronous send to the remote host.
pause_dataThis method pauses data reception.
process_dataThis method reenables data reception after a call to PauseData .
resetReset the class.
sendThis method sends binary data to the specified client.
send_bytesThis method sends binary data to the specified client.
send_fileThis method sends the file to the remote host.
send_lineThis method sends a string followed by a new line.
send_textThis method sends text to the specified client.
shutdownThis method shuts down the server.
start_listeningThis method starts listening for incoming connections.
start_sslThis method starts the Secure Sockets Layer (SSL) negotiation on a connection.
stop_listeningThis method stops listening for new connections.

Event List


The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

on_connectedThis event is fired immediately after a connection completes (or fails).
on_connection_requestThis event is fired when a request for connection comes from a remote host.
on_data_inThis event is fired when data come in.
on_disconnectedThis event is fired when a connection is closed.
on_errorThis event fires information about errors during data delivery.
on_ready_to_sendThis event is fired when the class is ready to send data.
on_ssl_client_authenticationThis event is fired when the client presents its credentials to the server.
on_ssl_connection_requestThis event fires when a Secure Sockets Layer (SSL) connection is requested.
on_ssl_statusThis event is fired to show the progress of the secure connection.

Config Settings


The following is a list of config settings for the class with short descriptions. Click on the links for further details.

AllowedClientsA comma-separated list of host names or IP addresses that can access the class.
BindExclusivelyWhether or not the class considers a local port reserved for exclusive use.
BlockedClientsA comma-separated list of host names or IP addresses that cannot access the class.
ConnectionUIDThe unique connectionId for a connection.
DefaultConnectionTimeoutThe inactivity timeout applied to the SSL handshake.
InBufferSizeThe size in bytes of the incoming queue of the socket.
KeepAliveIntervalThe retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.
KeepAliveRetryCountThe number of keep-alive packets to be sent before the remotehost is considered disconnected.
KeepAliveTimeThe inactivity time in milliseconds before a TCP keep-alive packet is sent.
MaxConnectionsThe maximum number of connections available.
MaxReadTimeThe maximum time spent reading data from each connection.
OutBufferSizeThe size in bytes of the outgoing queue of the socket.
TcpNoDelayWhether or not to delay when sending packets.
UseIOCPWhether to use the completion port I/O model.
UseIPv6Whether to use IPv6.
UseWindowsMessagesWhether to use the WSAAsyncSelect I/O model.
LogSSLPacketsControls whether SSL packets are logged when using the internal security API.
OpenSSLCADirThe path to a directory containing CA certificates.
OpenSSLCAFileName of the file containing the list of CA's trusted by your application.
OpenSSLCipherListA string that controls the ciphers to be used by SSL.
OpenSSLPrngSeedDataThe data to seed the pseudo random number generator (PRNG).
ReuseSSLSessionDetermines if the SSL session is reused.
SSLCACertFilePathsThe paths to CA certificate files on Unix/Linux.
SSLCACertsA newline separated list of CA certificate to use during SSL client authentication.
SSLCheckCRLWhether to check the Certificate Revocation List for the server certificate.
SSLCheckOCSPWhether to use OCSP to check the status of the server certificate.
SSLCipherStrengthThe minimum cipher strength used for bulk encryption.
SSLEnabledCipherSuitesThe cipher suite to be used in an SSL negotiation.
SSLEnabledProtocolsUsed to enable/disable the supported security protocols.
SSLEnableRenegotiationWhether the renegotiation_info SSL extension is supported.
SSLIncludeCertChainWhether the entire certificate chain is included in the SSLServerAuthentication event.
SSLKeyLogFileThe location of a file where per-session secrets are written for debugging purposes.
SSLNegotiatedCipherReturns the negotiated cipher suite.
SSLNegotiatedCipherStrengthReturns the negotiated cipher suite strength.
SSLNegotiatedCipherSuiteReturns the negotiated cipher suite.
SSLNegotiatedKeyExchangeReturns the negotiated key exchange algorithm.
SSLNegotiatedKeyExchangeStrengthReturns the negotiated key exchange algorithm strength.
SSLNegotiatedVersionReturns the negotiated protocol version.
SSLSecurityFlagsFlags that control certificate verification.
SSLServerCACertsA newline separated list of CA certificate to use during SSL server certificate validation.
TLS12SignatureAlgorithmsDefines the allowed TLS 1.2 signature algorithms when SSLProvider is set to Internal.
TLS12SupportedGroupsThe supported groups for ECC.
TLS13KeyShareGroupsThe groups for which to pregenerate key shares.
TLS13SignatureAlgorithmsThe allowed certificate signature algorithms.
TLS13SupportedGroupsThe supported groups for (EC)DHE key exchange.
BuildInfoInformation about the product's build.
CodePageThe system code page used for Unicode to Multibyte translations.
LicenseInfoInformation about the current license.
MaskSensitiveWhether sensitive data is masked in log messages.
ProcessIdleEventsWhether the class uses its internal event loop to process events when the main thread is idle.
SelectWaitMillisThe length of time in milliseconds the class will wait when DoEvents is called if there are no events to process.
UseInternalSecurityAPITells the class whether or not to use the system security libraries or an internal implementation.

connection_backlog Property

This property includes the maximum number of pending connections maintained by the Transmission Control Protocol (TCP)/IP subsystem.

Syntax

def get_connection_backlog() -> int: ...
def set_connection_backlog(value: int) -> None: ...

connection_backlog = property(get_connection_backlog, set_connection_backlog)

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.

connection_count Property

The number of records in the arrays.

Syntax

def get_connection_count() -> int: ...

connection_count = property(get_connection_count, None)

Default Value

0

Remarks

This property controls the size of the following arrays:

The array indices start at 0 and end at connection_count - 1.

This property is read-only.

accept_data Property

Setting this property to false temporarily disables data reception (and the DataIn event) for the connection.

Syntax

def get_accept_data(connection_id: int) -> bool: ...
def set_accept_data(connection_id: int, value: bool) -> None: ...

Default Value

TRUE

Remarks

Setting this property to false temporarily disables data reception (and the ondatain event) for the connection. Setting this to true re-enables data reception.

Note: It is recommended to use the pausedata or processdata method instead of setting this property.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

bytes_sent Property

This property shows how many bytes were sent after the last assignment to DataToSend .

Syntax

def get_bytes_sent(connection_id: int) -> int: ...

Default Value

0

Remarks

This property shows how many bytes were sent after the last assignment to datatosend. Please check datatosend for more information.

Note: This property will always return 0 when the class is operating in the synchronous mode (i.e., the timeout property is set to a positive value).

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

This property is read-only.

connected Property

This property is used to disconnect individual connections or to show their status.

Syntax

def get_connected(connection_id: int) -> bool: ...
def set_connected(connection_id: int, value: bool) -> None: ...

Default Value

FALSE

Remarks

This property is used to disconnect individual connections or to show their status.

The connected property may be set to False to close the connection.

connected also shows the status of a particular connection (connected/disconnected).

How and when the connection is closed is controlled by the linger property. Please refer to its description for more information.

Note: It is recommended to use the disconnect method instead of setting this property.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

connection_id Property

This property contains an identifier generated by the class to identify each connection.

Syntax

def get_connection_id(connection_id: int) -> str: ...

Default Value

""

Remarks

This property contains an identifier generated by the class to identify each connection. This identifier is unique to this connection.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

This property is read-only.

data_to_send Property

This property contains a string of data to be sent to the remote host.

Syntax

def set_data_to_send(connection_id: int, value: bytes) -> None: ...

Default Value

""

Remarks

This property contains a string of data to be sent to the remote host. It is a write-only property.

Assigning a string to the datatosend makes the class send the string to the remote host. The send method provides similar functionality.

When timeout is set to 0, the class 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 error 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 onreadytosend event before attempting to send data again.

Note: The onreadytosend event is not fired when part of the data is sent successfully.

Note: It is recommended to use the send or sendbytes method instead of setting this property.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

This property is write-only.

eol Property

The EOL property is used to define boundaries in the input stream using the value of the property.

Syntax

def get_eol(connection_id: int) -> bytes: ...
def set_eol(connection_id: int, value: bytes) -> None: ...

Default Value

""

Remarks

The eol property is used to define boundaries in the input stream using the value of the property.

The eol property 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 property is a binary string. This means that it can be more than one byte long, and it can contain NULL bytes.

When reading the value of the property, if ConnectionId does not belong to a valid connection, then NULL will be returned, and the lasterror property will contain a corresponding error message. If no error is encountered, then lasterror will contain NULL.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

idle_timeout Property

This property contains the idle timeout for this connection.

Syntax

def get_idle_timeout(connection_id: int) -> int: ...
def set_idle_timeout(connection_id: int, value: int) -> None: ...

Default Value

0

Remarks

This property contains the idle timeout for this connection. This property is similar to defaultidletimeout but may be set on a per-connection basis to override defaultidletimeout. This property specifies the idle timeout (in seconds) for the connected client. When set to a positive value, the class 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 class to check existing connections.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

local_address Property

This property shows the IP address of the interface through which the connection is passing.

Syntax

def get_local_address(connection_id: int) -> str: ...

Default Value

""

Remarks

This property shows the IP address of the interface through which the connection is passing.

localaddress is important for multihomed hosts so that it can be used to find the particular network interface through which an individual connection is going.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

This property is read-only.

ready_to_send Property

This indicates whether the class is ready to send data.

Syntax

def get_ready_to_send(connection_id: int) -> bool: ...

Default Value

FALSE

Remarks

This indicates whether the class is ready to send data.

This property indicates that the underlying TCP/IP subsystem is ready to accept data. This is True after a client connects but will become False after a failed datatosend.

After a failed datatosend, the onreadytosend event will fire and this property will be True when data can be sent again.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

This property is read-only.

record_length Property

If set to a positive value, this setting defines the length of the data records to be received.

Syntax

def get_record_length(connection_id: int) -> int: ...
def set_record_length(connection_id: int, value: int) -> None: ...

Default Value

0

Remarks

If set to a positive value, this setting defines the length of the data records to be received. The class will accumulate data until RecordLength is reached and only then will fire the ondatain event with the data of length RecordLength. This allows data to be received as records of known length. This value can be changed at any time, including within the ondatain event.

A value of 0 (default) means this setting is not used.

Note: It is recommended to use the changerecordlength method instead of setting this property.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

remote_host Property

This property shows the IP address of the remote host through which the connection is coming.

Syntax

def get_remote_host(connection_id: int) -> str: ...

Default Value

""

Remarks

This property 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 class is configured to use a SOCKS firewall, the value assigned to this property may be preceded with an "*". If this is the case, the host name is passed to the firewall unresolved and the firewall performs the DNS resolution.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

This property is read-only.

remote_port Property

This property shows the Transmission Control Protocol (TCP) port on the remote host through which the connection is coming.

Syntax

def get_remote_port(connection_id: int) -> int: ...

Default Value

0

Remarks

This property shows the Transmission Control Protocol (TCP) port on the remote host through which the connection is coming.

The connection must be valid or an error will be fired.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

This property is read-only.

single_line_mode Property

This property shows the special mode for line-oriented protocols.

Syntax

def get_single_line_mode(connection_id: int) -> bool: ...
def set_single_line_mode(connection_id: int, value: bool) -> None: ...

Default Value

FALSE

Remarks

This property shows the special mode for line-oriented protocols. When singlelinemode is True, the class treats the incoming data stream as lines separated by carriage return (CR), line feed (LF), or CRLF. The eol property is ignored.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

timeout Property

This property specifies a timeout for the class.

Syntax

def get_timeout(connection_id: int) -> int: ...
def set_timeout(connection_id: int, value: int) -> None: ...

Default Value

0

Remarks

This property specifies a timeout for the class.

If the timeout property is set to 0, all operations return immediately, potentially failing with a WOULDBLOCK error if data cannot be sent immediately.

If timeout is set to a positive value, data is sent in a blocking manner and the class will wait for the operation to complete before returning control. The class will handle any potential WOULDBLOCK errors internally and automatically retry the operation for a maximum of timeout seconds.

The class 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 class fails with an error.

Please note that by default, all timeouts are inactivity timeouts, i.e. the timeout period is extended by timeout seconds when any amount of data is successfully sent or received.

The default value for the timeout property is 0 (asynchronous operation).

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

user_data Property

The UserData property holds connection-specific user-specified data.

Syntax

def get_user_data(connection_id: int) -> bytes: ...
def set_user_data(connection_id: int, value: bytes) -> None: ...

Default Value

""

Remarks

The userdata property 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.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

default_eol Property

This property includes a default end-of-line (EOL) value to be used by incoming connections.

Syntax

def get_default_eol() -> bytes: ...
def set_default_eol(value: bytes) -> None: ...

default_eol = property(get_default_eol, set_default_eol)

Default Value

""

Remarks

This property contains a default end-of-line (EOL) value to be used by incoming connections. Once the class 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.

default_idle_timeout Property

This property includes the default idle timeout for inactive clients.

Syntax

def get_default_idle_timeout() -> int: ...
def set_default_idle_timeout(value: int) -> None: ...

default_idle_timeout = property(get_default_idle_timeout, set_default_idle_timeout)

Default Value

0

Remarks

This property specifies the idle timeout (in seconds) for clients. When set to a positive value, the class will disconnect idle clients after the specified timeout.

This applies only to clients that have not sent or received data within default_idle_timeout seconds.

If set to 0 (default), no idle timeout is applied.

Note: do_events must be called for the class to check existing connections.

default_max_line_length Property

The property includes the default maximum line length value for inbound connections.

Syntax

def get_default_max_line_length() -> int: ...
def set_default_max_line_length(value: int) -> None: ...

default_max_line_length = property(get_default_max_line_length, set_default_max_line_length)

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.

default_single_line_mode Property

This property tells the class whether or not to treat new connections as line oriented.

Syntax

def get_default_single_line_mode() -> bool: ...
def set_default_single_line_mode(value: bool) -> None: ...

default_single_line_mode = property(get_default_single_line_mode, set_default_single_line_mode)

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).

default_timeout Property

This property includes an initial timeout value to be used by incoming connections.

Syntax

def get_default_timeout() -> int: ...
def set_default_timeout(value: int) -> None: ...

default_timeout = property(get_default_timeout, set_default_timeout)

Default Value

0

Remarks

This property is used by the class to set the operational timeout value of all inbound connections once they are established.

By default, the timeout is 0, meaning that all inbound connections will behave asynchronously.

keep_alive Property

When True, KEEPALIVE packets are enabled (for long connections).

Syntax

def get_keep_alive() -> bool: ...
def set_keep_alive(value: bool) -> None: ...

keep_alive = property(get_keep_alive, set_keep_alive)

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

When set to True, connections are terminated gracefully.

Syntax

def get_linger() -> bool: ...
def set_linger(value: bool) -> None: ...

linger = property(get_linger, set_linger)

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 class 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

If set to True, the class accepts incoming connections on LocalPort.

Syntax

def get_listening() -> bool: ...
def set_listening(value: bool) -> None: ...

listening = property(get_listening, set_listening)

Default Value

FALSE

Remarks

This property indicates whether the class is listening for connections on the port specified by the local_port property.

Note: Use the start_listening and stop_listening methods to control whether the class is listening.

local_host Property

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

Syntax

def get_local_host() -> str: ...
def set_local_host(value: str) -> None: ...

local_host = property(get_local_host, set_local_host)

Default Value

""

Remarks

The local_host 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 multi-homed hosts (machines with more than one IP interface) setting LocalHost to the value of an interface will make the class initiate connections (or accept in the case of server classs) only through that interface.

If the class is connected, the local_host 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 multi-homed hosts (machines with more than one IP interface).

NOTE: local_host is not persistent. You must always set it in code, and never in the property window.

local_port Property

This property includes the Transmission Control Protocol (TCP) port in the local host where the class listens.

Syntax

def get_local_port() -> int: ...
def set_local_port(value: int) -> None: ...

local_port = property(get_local_port, set_local_port)

Default Value

0

Remarks

This property must be set before the class 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 class is listening (i.e., after successfully assigning True to the listening property).

The service port is not shared among servers so two classs cannot be listening on the same port at the same time.

ssl_authenticate_clients Property

If set to True, the server asks the client(s) for a certificate.

Syntax

def get_ssl_authenticate_clients() -> bool: ...
def set_ssl_authenticate_clients(value: bool) -> None: ...

ssl_authenticate_clients = property(get_ssl_authenticate_clients, set_ssl_authenticate_clients)

Default Value

FALSE

Remarks

This property is used in conjunction with the on_ssl_client_authentication event. Please refer to the documentation of the on_ssl_client_authentication event for details.

ssl_cert_encoded Property

This is the certificate (PEM/base64 encoded).

Syntax

def get_ssl_cert_encoded() -> bytes: ...
def set_ssl_cert_encoded(value: bytes) -> None: ...

ssl_cert_encoded = property(get_ssl_cert_encoded, set_ssl_cert_encoded)

Default Value

""

Remarks

This is the certificate (PEM/base64 encoded). This property is used to assign a specific certificate. The ssl_cert_store and ssl_cert_subject properties also may be used to specify a certificate.

When ssl_cert_encoded is set, a search is initiated in the current ssl_cert_store for the private key of the certificate. If the key is found, ssl_cert_subject is updated to reflect the full subject of the selected certificate; otherwise, ssl_cert_subject is set to an empty string.

ssl_cert_store Property

This is the name of the certificate store for the client certificate.

Syntax

def get_ssl_cert_store() -> bytes: ...
def set_ssl_cert_store(value: bytes) -> None: ...

ssl_cert_store = property(get_ssl_cert_store, set_ssl_cert_store)

Default Value

"MY"

Remarks

This is the name of the certificate store for the client certificate.

The ssl_cert_store_type property denotes the type of the certificate store specified by ssl_cert_store. If the store is password protected, specify the password in ssl_cert_store_password.

ssl_cert_store is used in conjunction with the ssl_cert_subject property to specify client certificates. If ssl_cert_store has a value, and ssl_cert_subject or ssl_cert_encoded is set, a search for a certificate is initiated. Please see the ssl_cert_subject property for details.

Designations of certificate stores are platform-dependent.

The following are designations of the most common User and Machine certificate stores in Windows:

MYA certificate store holding personal certificates with their associated private keys.
CACertifying authority certificates.
ROOTRoot certificates.

When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (i.e. PKCS12 certificate store).

ssl_cert_store_password Property

If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.

Syntax

def get_ssl_cert_store_password() -> str: ...
def set_ssl_cert_store_password(value: str) -> None: ...

ssl_cert_store_password = property(get_ssl_cert_store_password, set_ssl_cert_store_password)

Default Value

""

Remarks

If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.

ssl_cert_store_type Property

This is the type of certificate store for this certificate.

Syntax

def get_ssl_cert_store_type() -> int: ...
def set_ssl_cert_store_type(value: int) -> None: ...

ssl_cert_store_type = property(get_ssl_cert_store_type, set_ssl_cert_store_type)

Default Value

0

Remarks

This is the type of certificate store for this certificate.

The class supports both public and private keys in a variety of formats. When the cstAuto value is used the class will automatically determine the type. This property can take one of the following values:

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 (PKCS12) file containing certificates.
3 (cstPFXBlob)The certificate store is a string (binary or base64-encoded) representing a certificate store in PFX (PKCS12) 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 PKCS7 file containing certificates.
12 (cstP7BBlob)The certificate store is a string (binary) representing a certificate store in PKCS7 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 PKCS11 interface.

To use a security key the necessary data must first be collected using the CertMgr class. The list_store_certificates method may be called after setting cert_store_type to cstPKCS11, cert_store_password to the PIN, and cert_store to the full path of the PKCS11 dll. The certificate information returned in the on_cert_list event's CertEncoded parameter may be saved for later use.

When using a certificate, pass the previously saved security key information as the ssl_cert_store and set ssl_cert_store_password to the PIN.

Code Example: SSH Authentication with Security Key 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);

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.

ssl_cert_subject Property

This is the subject of the certificate used for client authentication.

Syntax

def get_ssl_cert_subject() -> str: ...
def set_ssl_cert_subject(value: str) -> None: ...

ssl_cert_subject = property(get_ssl_cert_subject, set_ssl_cert_subject)

Default Value

""

Remarks

This is the subject of the certificate used for client authentication.

This property must be set after all other certificate properties are set. When this property is set, a search is performed in the current certificate store to locate a certificate with a matching subject.

If a matching certificate is found, the property is set to the full subject of the matching certificate.

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=support@nsoftware.com". Common fields and their meanings are displayed below.

FieldMeaning
CNCommon Name. This is commonly a host name like www.server.com.
OOrganization
OUOrganizational Unit
LLocality
SState
CCountry
EEmail Address

If a field value contains a comma it must be quoted.

ssl_enabled Property

Whether TLS/SSL is enabled.

Syntax

def get_ssl_enabled() -> bool: ...
def set_ssl_enabled(value: bool) -> None: ...

ssl_enabled = property(get_ssl_enabled, set_ssl_enabled)

Default Value

FALSE

Remarks

This setting specifies whether TLS/SSL is enabled in the class. When False (default) the class operates in plaintext mode. When True TLS/SSL is enabled.

TLS/SSL may also be enabled by setting ssl_start_mode. Setting ssl_start_mode will automatically update this property value.

ssl_provider Property

This specifies the SSL/TLS implementation to use.

Syntax

def get_ssl_provider() -> int: ...
def set_ssl_provider(value: int) -> None: ...

ssl_provider = property(get_ssl_provider, set_ssl_provider)

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 class 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:

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 class will select a provider depending on the current platform.

When Automatic is selected, on Windows the class will use the platform implementation. On Linux/macOS the class will use the internal implementation. When TLS 1.3 is enabled via SSLEnabledProtocols the internal implementation is used on all platforms.

ssl_start_mode Property

Determines how the class starts the SSL negotiation.

Syntax

def get_ssl_start_mode() -> int: ...
def set_ssl_start_mode(value: int) -> None: ...

ssl_start_mode = property(get_ssl_start_mode, set_ssl_start_mode)

Default Value

3

Remarks

The ssl_start_mode 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 class will behave the same as if ssl_start_mode 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 class will first connect in plaintext, and then 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.

change_record_length Method

This method changes the length of received data records.

Syntax

def change_record_length(connection_id: int, record_length: int) -> None: ...

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 class will accumulate data until RecordLength bytes of data are received and only then will fire the on_data_in 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 on_data_in event.

A value of 0 (default) means this functionality is not used.

config Method

Sets or retrieves a configuration setting.

Syntax

def config(configuration_string: str) -> str: ...

Remarks

config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, 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, you must call Config("PROPERTY"). The value will be returned as a string.

disconnect Method

This method disconnects the specified client.

Syntax

def disconnect(connection_id: int) -> None: ...

Remarks

Calling this method will disconnect the client specified by the ConnectionId parameter.

do_events Method

Processes events from the internal message queue.

Syntax

def do_events() -> None: ...

Remarks

When do_events is called, the class processes any available events. If no events are available, it waits for a preset period of time, and then returns.

interrupt Method

This method interrupts a synchronous send to the remote host.

Syntax

def interrupt(connection_id: int) -> None: ...

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 class. If you use send_file to upload a file, the class will run synchronously on that Connection Id until it is completed.

pause_data Method

This method pauses data reception.

Syntax

def pause_data(connection_id: int) -> None: ...

Remarks

This method pauses data reception for the connection identified by ConnectionId when called. While data reception is paused, the on_data_in event will not fire for the specified connection. Call process_data to reenable data reception.

process_data Method

This method reenables data reception after a call to PauseData .

Syntax

def process_data(connection_id: int) -> None: ...

Remarks

This method reenables data reception for the connection identified by ConnectionId after a previous call to pause_data. When pause_data is called, the on_data_in event will not fire for the specified connection. To reenable data reception and allow on_data_in to fire, call this method.

Note: This method is used only after previously calling pause_data. It does not need to be called to process incoming data by default.

reset Method

Reset the class.

Syntax

def reset() -> None: ...

Remarks

This method will reset the class's properties to their default values.

send Method

This method sends binary data to the specified client.

Syntax

def send(connection_id: int, text: bytes) -> None: ...

Remarks

This method sends binary data to the client identified by ConnectionId. To send text, use the send_text method instead.

When ws_connection_timeout is set to 0, the class 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 error 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again. . The bytes_sent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the on_ready_to_send event before attempting to send data again.

Note: The on_ready_to_send event is not fired when part of the data is sent successfully.

send_bytes Method

This method sends binary data to the specified client.

Syntax

def send_bytes(connection_id: int, data: bytes) -> None: ...

Remarks

This method sends binary data to the client identified by ConnectionId. To send text, use the send_text method instead.

When ws_connection_timeout is set to 0, the class 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 error 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again. . The bytes_sent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the on_ready_to_send event before attempting to send data again.

Note: The on_ready_to_send event is not fired when part of the data is sent successfully.

send_file Method

This method sends the file to the remote host.

Syntax

def send_file(connection_id: int, file_name: str) -> None: ...

Remarks

This method sends the file to the client specified by the ConnectionId.

send_line Method

This method sends a string followed by a new line.

Syntax

def send_line(connection_id: int, text: str) -> None: ...

Remarks

This method is used to send data with line-oriented protocols. The line is followed by CRLF ("\r\n") .

Please refer to the get_line method and single_line_mode property for more information.

send_text Method

This method sends text to the specified client.

Syntax

def send_text(connection_id: int, text: str) -> None: ...

Remarks

This method sends text to the client identified by ConnectionId. To send binary data, use the send_bytes method instead.

When ws_connection_timeout is set to 0, the class 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 error 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again. . The bytes_sent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the on_ready_to_send event before attempting to send data again.

Note: The on_ready_to_send event is not fired when part of the data is sent successfully.

shutdown Method

This method shuts down the server.

Syntax

def shutdown() -> None: ...

Remarks

This method shuts down the server. Calling this method is equivalent to calling stop_listening and then breaking every client connection by calling disconnect.

start_listening Method

This method starts listening for incoming connections.

Syntax

def start_listening() -> None: ...

Remarks

This method begins listening for incoming connections on the port specified by local_port. Once listening, events will fire as new clients connect and data are transferred.

To stop listening for new connections, call stop_listening. To stop listening for new connections and to disconnect all existing clients, call shutdown.

start_ssl Method

This method starts the Secure Sockets Layer (SSL) negotiation on a connection.

Syntax

def start_ssl(connection_id: int) -> None: ...

Remarks

This method is used to start the SSL negotiation on a plaintext connection. Please refer to the ssl_start_mode property for more information.

Note: The on_connected event will fire again after the SSL negotiation is complete.

stop_listening Method

This method stops listening for new connections.

Syntax

def stop_listening() -> None: ...

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 instead.

on_connected Event

This event is fired immediately after a connection completes (or fails).

Syntax

class TCPServerConnectedEventParams(object):
  @property
  def connection_id() -> int: ...

  @property
  def status_code() -> int: ...

  @property
  def description() -> str: ...

# In class TCPServer:
@property
def on_connected() -> Callable[[TCPServerConnectedEventParams], None]: ...
@on_connected.setter
def on_connected(event_hook: Callable[[TCPServerConnectedEventParams], None]) -> None: ...

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 section for more information.

on_connection_request Event

This event is fired when a request for connection comes from a remote host.

Syntax

class TCPServerConnectionRequestEventParams(object):
  @property
  def address() -> str: ...

  @property
  def port() -> int: ...

  @property
  def accept() -> bool: ...
  @accept.setter
  def accept(value) -> None: ...

# In class TCPServer:
@property
def on_connection_request() -> Callable[[TCPServerConnectionRequestEventParams], None]: ...
@on_connection_request.setter
def on_connection_request(event_hook: Callable[[TCPServerConnectionRequestEventParams], None]) -> None: ...

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.

on_data_in Event

This event is fired when data come in.

Syntax

class TCPServerDataInEventParams(object):
  @property
  def connection_id() -> int: ...

  @property
  def text() -> bytes: ...

  @property
  def eol() -> bool: ...

# In class TCPServer:
@property
def on_data_in() -> Callable[[TCPServerDataInEventParams], None]: ...
@on_data_in.setter
def on_data_in(event_hook: Callable[[TCPServerDataInEventParams], None]) -> None: ...

Remarks

Trapping the on_data_in 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 default_max_line_length or with no eol strings in it, then EOL is False. Please note that this means that one or more on_data_in 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.

on_disconnected Event

This event is fired when a connection is closed.

Syntax

class TCPServerDisconnectedEventParams(object):
  @property
  def connection_id() -> int: ...

  @property
  def status_code() -> int: ...

  @property
  def description() -> str: ...

# In class TCPServer:
@property
def on_disconnected() -> Callable[[TCPServerDisconnectedEventParams], None]: ...
@on_disconnected.setter
def on_disconnected(event_hook: Callable[[TCPServerDisconnectedEventParams], None]) -> None: ...

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 section for more information.

on_error Event

This event fires information about errors during data delivery.

Syntax

class TCPServerErrorEventParams(object):
  @property
  def connection_id() -> int: ...

  @property
  def error_code() -> int: ...

  @property
  def description() -> str: ...

# In class TCPServer:
@property
def on_error() -> Callable[[TCPServerErrorEventParams], None]: ...
@on_error.setter
def on_error(event_hook: Callable[[TCPServerErrorEventParams], None]) -> None: ...

Remarks

The on_error event is fired in case of exceptional conditions during message processing. Normally, the class fails with an error.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

ConnectionId indicates the connection for which the error is applicable.

on_ready_to_send Event

This event is fired when the class is ready to send data.

Syntax

class TCPServerReadyToSendEventParams(object):
  @property
  def connection_id() -> int: ...

# In class TCPServer:
@property
def on_ready_to_send() -> Callable[[TCPServerReadyToSendEventParams], None]: ...
@on_ready_to_send.setter
def on_ready_to_send(event_hook: Callable[[TCPServerReadyToSendEventParams], None]) -> None: ...

Remarks

The on_ready_to_send event indicates that the underlying Transmission Control Protocol (TCP)/IP subsystem is ready to accept data after a failed data_to_send. This event is also fired immediately after a connection is established.

on_ssl_client_authentication Event

This event is fired when the client presents its credentials to the server.

Syntax

class TCPServerSSLClientAuthenticationEventParams(object):
  @property
  def connection_id() -> int: ...

  @property
  def cert_encoded() -> bytes: ...

  @property
  def cert_subject() -> str: ...

  @property
  def cert_issuer() -> str: ...

  @property
  def status() -> str: ...

  @property
  def accept() -> bool: ...
  @accept.setter
  def accept(value) -> None: ...

# In class TCPServer:
@property
def on_ssl_client_authentication() -> Callable[[TCPServerSSLClientAuthenticationEventParams], None]: ...
@on_ssl_client_authentication.setter
def on_ssl_client_authentication(event_hook: Callable[[TCPServerSSLClientAuthenticationEventParams], None]) -> None: ...

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").

on_ssl_connection_request Event

This event fires when a Secure Sockets Layer (SSL) connection is requested.

Syntax

class TCPServerSSLConnectionRequestEventParams(object):
  @property
  def connection_id() -> int: ...

  @property
  def supported_cipher_suites() -> str: ...

  @property
  def supported_signature_algs() -> str: ...

  @property
  def cert_store_type() -> int: ...
  @cert_store_type.setter
  def cert_store_type(value) -> None: ...

  @property
  def cert_store() -> str: ...
  @cert_store.setter
  def cert_store(value) -> None: ...

  @property
  def cert_password() -> str: ...
  @cert_password.setter
  def cert_password(value) -> None: ...

  @property
  def cert_subject() -> str: ...
  @cert_subject.setter
  def cert_subject(value) -> None: ...

# In class TCPServer:
@property
def on_ssl_connection_request() -> Callable[[TCPServerSSLConnectionRequestEventParams], None]: ...
@on_ssl_connection_request.setter
def on_ssl_connection_request(event_hook: Callable[[TCPServerSSLConnectionRequestEventParams], None]) -> None: ...

Remarks

This event fires when an SSL connection is requested and ssl_provider is set to Internal. This event provides an opportunity to select an alternative certificate to the connecting client. This event does not fire when ssl_provider is set to Platform.

This event allows the class 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 class supports both public and private keys in a variety of formats. When the cstAuto value is used the class will automatically determine the type. This property can take one of the following values:

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 (PKCS12) file containing certificates.
3 (cstPFXBlob)The certificate store is a string (binary or base64-encoded) representing a certificate store in PFX (PKCS12) 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 PKCS7 file containing certificates.
12 (cstP7BBlob)The certificate store is a string (binary) representing a certificate store in PKCS7 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 PKCS11 interface.

To use a security key the necessary data must first be collected using the CertMgr class. The list_store_certificates method may be called after setting cert_store_type to cstPKCS11, cert_store_password to the PIN, and cert_store to the full path of the PKCS11 dll. The certificate information returned in the on_cert_list event's CertEncoded parameter may be saved for later use.

When using a certificate, pass the previously saved security key information as the and set to the PIN.

Code Example: SSH Authentication with Security Key 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);

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 are designations of the most common User and Machine certificate stores in Windows:

MYA certificate store holding personal certificates with their associated private keys.
CACertifying authority certificates.
ROOTRoot certificates.

When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (i.e. PKCS12 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=support@nsoftware.com". Common fields and their meanings are displayed below.

FieldMeaning
CNCommon Name. This is commonly a host name like www.server.com.
OOrganization
OUOrganizational Unit
LLocality
SState
CCountry
EEmail Address

If a field value contains a comma it must be quoted.

on_ssl_status Event

This event is fired to show the progress of the secure connection.

Syntax

class TCPServerSSLStatusEventParams(object):
  @property
  def connection_id() -> int: ...

  @property
  def message() -> str: ...

# In class TCPServer:
@property
def on_ssl_status() -> Callable[[TCPServerSSLStatusEventParams], None]: ...
@on_ssl_status.setter
def on_ssl_status(event_hook: Callable[[TCPServerSSLStatusEventParams], None]) -> None: ...

Remarks

The event is fired for informational and logging purposes only. It is used to track the progress of the connection.

TCPServer Config Settings

The class 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 class, access to these internal properties is provided through the config method.

TCPServer Config Settings

AllowedClients:   A comma-separated list of host names or IP addresses that can access the class.

This configuration setting defines a comma-separated list of host names or IPv4 addresses that may access the class. 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 on_connection_request event fires with an Accept value set to False. If no action is taken within the on_connection_request 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 class.

This configuration setting defines a comma-separated list of host names or IPv4 addresses that cannot access the class.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 on_connection_request event fires with an Accept value set to False. If no action is taken within the on_connection_request event, the client will not be connected.

ConnectionUID:   The unique connectionId for a connection.

Connection Ids may be reused as clients connect and disconnect. Querying ConnectionUID will return a unique identifier for that connection Id. If the specified connection Id does not exist, then ConnectionUID will return 0. For example:

Connection5UID = obj.config("ConnectionUID[5]")

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 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 class is activated, the InBufferSize reverts to its defined size. The same thing will happen if you attempt to make it too large or too small.

InBufferSize 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.

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. 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.

KeepAliveRetryCount:   The number of keep-alive packets to be sent before the remotehost is considered disconnected.

When set, TCPKeepAlive will automatically be set to True. A TCP keep-alive packet will be sent after a period of inactivity, as defined by KeepAliveTime. If no acknowledgment is received from the remote host, the keep-alive packet will be sent again. This setting specifies the number of times that the keep-alive packets will be sent again before the remote host is considered disconnected. If this value is not specified here, the system default is 9.

Note: This configuration setting is available only in the Unix platform, and it is not supported in macOS or FreeBSD.

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 property must be set before listening is set to True, and once set, it can no longer be changed for the current instance of the class. The maximum value for this setting is 100,000 connections. Use this setting with caution. Extremely large values may affect performance. The default value is 1000.

Note: Unix/Linux operating systems limit the number of simultaneous connections to 1024.

MaxReadTime:   The maximum time spent reading data from each connection.

This setting specifies the maximum time in milliseconds that the class will spend reading data from a particular connection before servicing other connections. When a single client is sending data to the class at a high rate this setting is used to ensure that other connections are serviced in a timely manner. Specifying a positive value prevents a single client from monopolizing the class's resources. The special value of 0 indicates no limit and is generally not recommended.

The default value is 50 (milliseconds).

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 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 class is activated the OutBufferSize reverts to its defined size. The same thing will happen if you attempt to make it too large or too small.

OutBufferSize 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.

TcpNoDelay:   Whether or not to delay when sending packets.

When true, the socket will send all data that is ready to send at once. When false, the socket will send smaller buffered packets of data at small intervals. This is known as the Nagle algorithm.

By default, this config is set to false.

UseIOCP:   Whether to use the completion port I/O model.

The default value is False. When set to True, the class will use an I/O Completion Port (IOCP) to manage operations on sockets. A single completion port allows the asynchronous notification of network events on an entire group of sockets. This property must be set before listening is set to True.

Nothing else is required to begin accepting IOCP connections. One major benefit to using this model is that there will be no thread blocked waiting for a request to complete. The system notifies the process through an Asynchronous Procedure Call (APC) once the device driver finishes servicing the I/O request. IOCP allows a single I/O worker thread handle multiple clients' input/output "fairly".

Note: When set to True, this setting will automatically set UseWindowsMessages to False.

UseIPv6:   Whether to use IPv6.

When set to 0 (default), the class will use IPv4 exclusively. When set to 1, the class will use IPv6 exclusively. When set to 2, the class 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
UseWindowsMessages:   Whether to use the WSAAsyncSelect I/O model.

The default value is True, and the class will receive a Windows message-based notification of network events. Turning on Windows message notifications allows the application to get connect, send, receive, and socket closure network event notifications on a socket. This property must be set before listening is set to True.

Nothing else is required to begin accepting connections using the Windows message queue. In high-traffic environments, messages will be discarded if the queue is full. Additionally, because a single window procedure will service all events on thousands of sockets, the Windows message queue is not scalable from a performance perspective.

If this setting is set to False, the class will instead use the Winsock select model instead.

SSL Config Settings

LogSSLPackets:   Controls whether SSL packets are logged when using the internal security API.

When ssl_provider is set to Internal, this setting controls whether SSL packets should be logged. By default, this setting is False, as it is only useful for debugging purposes.

When enabled, SSL packet logs are output using the on_ssl_status event, which will fire each time an SSL packet is sent or received.

Enabling this setting has no effect if ssl_provider is set to Platform.

OpenSSLCADir:   The path to a directory containing CA certificates.

This functionality is available only when the provider is OpenSSL.

The path set by this property should point to a directory containing CA certificates in PEM format. The files each contain one CA certificate. The files are looked up by the CA subject name hash value, which must hence be available. If more than one CA certificate with the same name hash value exist, the extension must be different (e.g. 9d66eef0.0, 9d66eef0.1 etc). OpenSSL recommends to use the c_rehash utility to create the necessary links. Please refer to the OpenSSL man page SSL_CTX_load_verify_locations(3) for details.

OpenSSLCAFile:   Name of the file containing the list of CA's trusted by your application.

This functionality is available only when the provider is OpenSSL.

The file set by this property should contain a list of CA certificates in PEM format. The file can contain several CA certificates identified by

-----BEGIN CERTIFICATE-----

... (CA certificate in base64 encoding) ...

-----END CERTIFICATE-----

sequences. Before, between, and after the certificates text is allowed which can be used e.g. for descriptions of the certificates. Please refer to the OpenSSL man page SSL_CTX_load_verify_locations(3) for details.

OpenSSLCipherList:   A string that controls the ciphers to be used by SSL.

This functionality is available only when the provider is OpenSSL.

The format of this string is described in the OpenSSL man page ciphers(1) section "CIPHER LIST FORMAT". Please refer to it for details. The default string "DEFAULT" is determined at compile time and is normally equivalent to "ALL:!ADH:RC4+RSA:+SSLv2:@STRENGTH".

OpenSSLPrngSeedData:   The data to seed the pseudo random number generator (PRNG).

This functionality is available only when the provider is OpenSSL.

By default OpenSSL uses the device file "/dev/urandom" to seed the PRNG and setting OpenSSLPrngSeedData is not required. If set, the string specified is used to seed the PRNG.

ReuseSSLSession:   Determines if the SSL session is reused.

If set to true, the class 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 class is the same.

SSLCACertFilePaths:   The paths to CA certificate files on Unix/Linux.

This setting specifies the paths on disk to CA certificate files on Unix/Linux.

The value is formatted as a list of paths separated by semicolons. The class 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:

/etc/ssl/ca-bundle.pem;/etc/pki/tls/certs/ca-bundle.crt;/etc/ssl/certs/ca-certificates.crt;/etc/pki/tls/cacert.pem

SSLCACerts:   A newline separated list of CA certificate to use during SSL client authentication.

This setting specifies one or more CA certificates to be included in the request when performing SSL client authentication. Some servers require the entire chain, including CA certificates, to be presented when performing SSL client authentication. The value of this setting is a newline (CrLf) separated list of certificates. For instance:

-----BEGIN CERTIFICATE-----
MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw
...
eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w
F0I1XhM+pKj7FjDr+XNj
-----END CERTIFICATE-----
\r \n
-----BEGIN CERTIFICATE-----
MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp
..
d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA
-----END CERTIFICATE-----

SSLCheckCRL:   Whether to check the Certificate Revocation List for the server certificate.

This setting specifies whether the class will check the Certificate Revocation List specified by the server certificate. If set to 1 or 2, the class will first obtain the list of CRL URLs from the server certificate's CRL distribution points extension. The class 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 class fails with an error.

When set to 0 (default) the CRL check will not be performed by the class. When set to 1, it will attempt to perform the CRL check, but 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 only supported in the Java, C#, and C++ editions. In the C++ edition, it is only supported on Windows operating systems.

SSLCheckOCSP:   Whether to use OCSP to check the status of the server certificate.

This setting specifies whether the class will use OCSP to check the validity of the server certificate. If set to 1 or 2, the class will first obtain the OCSP URL from the server certificate's OCSP extension. The class 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 class fails with an error.

When set to 0 (default) the class will not perform an OCSP check. When set to 1, it will attempt to perform the OCSP check, but 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 only supported in the Java, C#, and C++ editions. In the C++ edition, it is only supported on Windows operating systems.

SSLCipherStrength:   The minimum cipher strength used for bulk encryption.

This minimum cipher strength 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.

Please note that this setting contains the minimum cipher strength requested from the security library. The actual cipher strength used for the connection is shown by the on_ssl_status event.

Use this 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 is currently not supported. This functionality is instead made available through the OpenSSLCipherList config setting.

SSLEnabledCipherSuites:   The cipher suite to be used in an SSL negotiation.

The enabled 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 class will pick all of the supported cipher suites. If 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 ssl_provider is set to Platform: obj.config("SSLEnabledCipherSuites=*"); obj.config("SSLEnabledCipherSuites=CALG_AES_256"); obj.config("SSLEnabledCipherSuites=CALG_AES_256;CALG_3DES"); Possible values when ssl_provider is set to Platform include:

  • 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 ssl_provider is set to Internal: 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_DH_ANON_WITH_AES_128_CBC_SHA"); Possible values when ssl_provider is set to Internal include:
  • 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_DH_RSA_WITH_AES_128_GCM_SHA256 (Not Recommended)
  • TLS_DH_RSA_WITH_AES_256_GCM_SHA384 (Not Recommended)
  • TLS_DH_DSS_WITH_AES_128_GCM_SHA256 (Not Recommended)
  • TLS_DH_DSS_WITH_AES_256_GCM_SHA384 (Not Recommended)
  • 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) only the following cipher suites are supported:

  • TLS_AES_256_GCM_SHA384
  • TLS_CHACHA20_POLY1305_SHA256
  • TLS_AES_128_GCM_SHA256

SSLEnabledCipherSuites is used together with SSLCipherStrength.

SSLEnabledProtocols:   Used to enable/disable the supported security protocols.

Used to enable/disable the supported security protocols.

Not all supported protocols are enabled by default (the value of this setting is 4032). If you want more granular control over the enabled protocols, you can set this property to the binary 'OR' of one or more of the following values:

TLS1.312288 (Hex 3000)
TLS1.23072 (Hex C00) (Default)
TLS1.1768 (Hex 300) (Default)
TLS1 192 (Hex C0) (Default)
SSL3 48 (Hex 30)
SSL2 12 (Hex 0C)

SSLEnabledProtocols - TLS 1.3 Notes

By default when TLS 1.3 is enabled the class will use the internal TLS implementation when the ssl_provider is set to Automatic for all editions.

In editions which are designed to run on Windows ssl_provider 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 only supported 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 only available on Windows 11 / Windows Server 2022 and up.
  • SSLEnabledCipherSuites and other similar SSL configuration settings are not supported.
  • If SSLEnabledProtocols includes both TLS 1.3 and TLS 1.2 the above 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.

SSLEnableRenegotiation:   Whether the renegotiation_info SSL extension is supported.

This setting specifies whether the renegotiation_info SSL extension will be used in the request when using the internal security API. This setting is True by default, but can be set to False to disable the extension.

This setting is only applicable when ssl_provider is set to Internal.

SSLIncludeCertChain:   Whether the entire certificate chain is included in the SSLServerAuthentication event.

This setting specifies whether the Encoded parameter of the on_ssl_server_authentication 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 on_ssl_server_authentication event.

If set to True all certificates returned by the server will be present in the Encoded parameter of the on_ssl_server_authentication event. This includes the leaf certificate, any intermediate certificate, and the root certificate.

SSLKeyLogFile:   The location of a file where per-session secrets are written for debugging purposes.

This setting optionally specifies the full path to a file on disk where per-session secrets are stored for debugging purposes.

When set, the class 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 traffice for debugging purposes. When writing to this file the class will only append, it will not overwrite previous values.

Note: This setting is only applicable when ssl_provider is set to Internal.

SSLNegotiatedCipher:   Returns the negotiated cipher suite.

Returns the cipher suite negotiated during the SSL handshake.

Note: For server components (e.g. TCPServer) this is a per-connection setting accessed by passing the ConnectionId. For example: server.Config("SSLNegotiatedCipher[connId]");

SSLNegotiatedCipherStrength:   Returns the negotiated cipher suite strength.

Returns the strength of the cipher suite negotiated during the SSL handshake.

Note: For server components (e.g.TCPServer) this is a per-connection setting accessed by passing the ConnectionId. For example: server.Config("SSLNegotiatedCipherStrength[connId]");

SSLNegotiatedCipherSuite:   Returns the negotiated cipher suite.

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 setting accessed by passing the ConnectionId. For example: server.Config("SSLNegotiatedCipherSuite[connId]");

SSLNegotiatedKeyExchange:   Returns the negotiated key exchange algorithm.

Returns the key exchange algorithm negotiated during the SSL handshake.

Note: For server components (e.g. TCPServer) this is a per-connection setting accessed by passing the ConnectionId. For example: server.Config("SSLNegotiatedKeyExchange[connId]");

SSLNegotiatedKeyExchangeStrength:   Returns the negotiated key exchange algorithm strength.

Returns the strenghth of the key exchange algorithm negotiated during the SSL handshake.

Note: For server components (e.g. TCPServer) this is a per-connection setting accessed by passing the ConnectionId. For example: server.Config("SSLNegotiatedKeyExchangeStrength[connId]");

SSLNegotiatedVersion:   Returns the negotiated protocol version.

Returns the protocol version negotiated during the SSL handshake.

Note: For server components (e.g. TCPServer) this is a per-connection setting accessed by passing the ConnectionId. For example: server.Config("SSLNegotiatedVersion[connId]");

SSLSecurityFlags:   Flags that control certificate verification.

The following flags are defined (specified in hexadecimal notation). They can be or-ed together to exclude multiple conditions:

0x00000001Ignore time validity status of certificate.
0x00000002Ignore time validity status of CTL.
0x00000004Ignore non-nested certificate times.
0x00000010Allow unknown Certificate Authority.
0x00000020Ignore wrong certificate usage.
0x00000100Ignore unknown certificate revocation status.
0x00000200Ignore unknown CTL signer revocation status.
0x00000400Ignore unknown Certificate Authority revocation status.
0x00000800Ignore unknown Root revocation status.
0x00008000Allow test Root certificate.
0x00004000Trust test Root certificate.
0x80000000Ignore non-matching CN (certificate CN not-matching server name).

This functionality is currently not available when the provider is OpenSSL.

SSLServerCACerts:   A newline separated list of CA certificate to use during SSL server certificate validation.

This setting optionally specifies one or more CA certificates to be used when 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 setting should only be set 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 setting is a newline (CrLf) separated list of certificates. For instance:

-----BEGIN CERTIFICATE-----
MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw
...
eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w
F0I1XhM+pKj7FjDr+XNj
-----END CERTIFICATE-----
\r \n
-----BEGIN CERTIFICATE-----
MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp
..
d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA
-----END CERTIFICATE-----

TLS12SignatureAlgorithms:   Defines the allowed TLS 1.2 signature algorithms when SSLProvider is set to Internal.

This setting specifies the allowed server certificate signature algorithms when ssl_provider is set to Internal and SSLEnabledProtocols is set to allow TLS 1.2.

When specified the class will verify that the server certificate signature algorithm is among the values specified in this setting. If the server certificate signature algorithm is unsupported the class fails with an error.

The format of this value is a comma separated list of hash-signature combinations. For instance: 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 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.

In order to not restrict the server's certificate signature algorithm, specify an empty string as the value for this setting, which will cause the signature_algorithms TLS 1.2 extension to not be sent.

TLS12SupportedGroups:   The supported groups for ECC.

This 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 ssl_provider 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 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 round trip 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 setting.

Note: All supported groups can always be used during the handshake even if not listed here, but if a group is used which is not present in this list it will incur an additional round trip and time to generate the key share for that group.

In most cases this setting does not need to be modified. This should only be modified 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 setting holds a comma separated list of allowed signature algorithms. Possible values are:

  • "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 setting is only applicable when SSLEnabledProtocols includes TLS 1.3.
TLS13SupportedGroups:   The supported groups for (EC)DHE key exchange.

This setting specifies a comma separated list of named groups used in TLS 1.3 for key exchange. This setting should only be modified 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

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)

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.

CodePage:   The system code page used for Unicode to Multibyte translations.

The default code page is Unicode UTF-8 (65001).

The following is a list of valid code page identifiers:

IdentifierName
037IBM EBCDIC - U.S./Canada
437OEM - United States
500IBM EBCDIC - International
708Arabic - ASMO 708
709Arabic - ASMO 449+, BCON V4
710Arabic - Transparent Arabic
720Arabic - Transparent ASMO
737OEM - Greek (formerly 437G)
775OEM - Baltic
850OEM - Multilingual Latin I
852OEM - Latin II
855OEM - Cyrillic (primarily Russian)
857OEM - Turkish
858OEM - Multilingual Latin I + Euro symbol
860OEM - Portuguese
861OEM - Icelandic
862OEM - Hebrew
863OEM - Canadian-French
864OEM - Arabic
865OEM - Nordic
866OEM - Russian
869OEM - Modern Greek
870IBM EBCDIC - Multilingual/ROECE (Latin-2)
874ANSI/OEM - Thai (same as 28605, ISO 8859-15)
875IBM EBCDIC - Modern Greek
932ANSI/OEM - Japanese, Shift-JIS
936ANSI/OEM - Simplified Chinese (PRC, Singapore)
949ANSI/OEM - Korean (Unified Hangul Code)
950ANSI/OEM - Traditional Chinese (Taiwan; Hong Kong SAR, PRC)
1026IBM EBCDIC - Turkish (Latin-5)
1047IBM EBCDIC - Latin 1/Open System
1140IBM EBCDIC - U.S./Canada (037 + Euro symbol)
1141IBM EBCDIC - Germany (20273 + Euro symbol)
1142IBM EBCDIC - Denmark/Norway (20277 + Euro symbol)
1143IBM EBCDIC - Finland/Sweden (20278 + Euro symbol)
1144IBM EBCDIC - Italy (20280 + Euro symbol)
1145IBM EBCDIC - Latin America/Spain (20284 + Euro symbol)
1146IBM EBCDIC - United Kingdom (20285 + Euro symbol)
1147IBM EBCDIC - France (20297 + Euro symbol)
1148IBM EBCDIC - International (500 + Euro symbol)
1149IBM EBCDIC - Icelandic (20871 + Euro symbol)
1200Unicode UCS-2 Little-Endian (BMP of ISO 10646)
1201Unicode UCS-2 Big-Endian
1250ANSI - Central European
1251ANSI - Cyrillic
1252ANSI - Latin I
1253ANSI - Greek
1254ANSI - Turkish
1255ANSI - Hebrew
1256ANSI - Arabic
1257ANSI - Baltic
1258ANSI/OEM - Vietnamese
1361Korean (Johab)
10000MAC - Roman
10001MAC - Japanese
10002MAC - Traditional Chinese (Big5)
10003MAC - Korean
10004MAC - Arabic
10005MAC - Hebrew
10006MAC - Greek I
10007MAC - Cyrillic
10008MAC - Simplified Chinese (GB 2312)
10010MAC - Romania
10017MAC - Ukraine
10021MAC - Thai
10029MAC - Latin II
10079MAC - Icelandic
10081MAC - Turkish
10082MAC - Croatia
12000Unicode UCS-4 Little-Endian
12001Unicode UCS-4 Big-Endian
20000CNS - Taiwan
20001TCA - Taiwan
20002Eten - Taiwan
20003IBM5550 - Taiwan
20004TeleText - Taiwan
20005Wang - Taiwan
20105IA5 IRV International Alphabet No. 5 (7-bit)
20106IA5 German (7-bit)
20107IA5 Swedish (7-bit)
20108IA5 Norwegian (7-bit)
20127US-ASCII (7-bit)
20261T.61
20269ISO 6937 Non-Spacing Accent
20273IBM EBCDIC - Germany
20277IBM EBCDIC - Denmark/Norway
20278IBM EBCDIC - Finland/Sweden
20280IBM EBCDIC - Italy
20284IBM EBCDIC - Latin America/Spain
20285IBM EBCDIC - United Kingdom
20290IBM EBCDIC - Japanese Katakana Extended
20297IBM EBCDIC - France
20420IBM EBCDIC - Arabic
20423IBM EBCDIC - Greek
20424IBM EBCDIC - Hebrew
20833IBM EBCDIC - Korean Extended
20838IBM EBCDIC - Thai
20866Russian - KOI8-R
20871IBM EBCDIC - Icelandic
20880IBM EBCDIC - Cyrillic (Russian)
20905IBM EBCDIC - Turkish
20924IBM EBCDIC - Latin-1/Open System (1047 + Euro symbol)
20932JIS X 0208-1990 & 0121-1990
20936Simplified Chinese (GB2312)
21025IBM EBCDIC - Cyrillic (Serbian, Bulgarian)
21027Extended Alpha Lowercase
21866Ukrainian (KOI8-U)
28591ISO 8859-1 Latin I
28592ISO 8859-2 Central Europe
28593ISO 8859-3 Latin 3
28594ISO 8859-4 Baltic
28595ISO 8859-5 Cyrillic
28596ISO 8859-6 Arabic
28597ISO 8859-7 Greek
28598ISO 8859-8 Hebrew
28599ISO 8859-9 Latin 5
28605ISO 8859-15 Latin 9
29001Europa 3
38598ISO 8859-8 Hebrew
50220ISO 2022 Japanese with no halfwidth Katakana
50221ISO 2022 Japanese with halfwidth Katakana
50222ISO 2022 Japanese JIS X 0201-1989
50225ISO 2022 Korean
50227ISO 2022 Simplified Chinese
50229ISO 2022 Traditional Chinese
50930Japanese (Katakana) Extended
50931US/Canada and Japanese
50933Korean Extended and Korean
50935Simplified Chinese Extended and Simplified Chinese
50936Simplified Chinese
50937US/Canada and Traditional Chinese
50939Japanese (Latin) Extended and Japanese
51932EUC - Japanese
51936EUC - Simplified Chinese
51949EUC - Korean
51950EUC - Traditional Chinese
52936HZ-GB2312 Simplified Chinese
54936Windows XP: GB18030 Simplified Chinese (4 Byte)
57002ISCII Devanagari
57003ISCII Bengali
57004ISCII Tamil
57005ISCII Telugu
57006ISCII Assamese
57007ISCII Oriya
57008ISCII Kannada
57009ISCII Malayalam
57010ISCII Gujarati
57011ISCII Punjabi
65000Unicode UTF-7
65001Unicode UTF-8
The following is a list of valid code page identifiers for Mac OS only:
IdentifierName
1ASCII
2NEXTSTEP
3JapaneseEUC
4UTF8
5ISOLatin1
6Symbol
7NonLossyASCII
8ShiftJIS
9ISOLatin2
10Unicode
11WindowsCP1251
12WindowsCP1252
13WindowsCP1253
14WindowsCP1254
15WindowsCP1250
21ISO2022JP
30MacOSRoman
10UTF16String
0x90000100UTF16BigEndian
0x94000100UTF16LittleEndian
0x8c000100UTF32String
0x98000100UTF32BigEndian
0x9c000100UTF32LittleEndian
65536Proprietary

LicenseInfo:   Information about the current license.

When queried, this setting will return a string containing information about the license this instance of a class 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.
MaskSensitive:   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.

This setting only works on these classes: AS3Receiver, AS3Sender, Atom, Client(3DS), FTP, FTPServer, IMAP, OFTPClient, SSHClient, SCP, Server(3DS), Sexec, SFTP, SFTPServer, SSHServer, TCPClient, TCPServer.

ProcessIdleEvents:   Whether the class uses its internal event loop to process events when the main thread is idle.

If set to False, the class will not fire internal idle events. Set this to False to use the class in a background thread on Mac OS. By default, this setting is True.

SelectWaitMillis:   The length of time in milliseconds the class will wait when DoEvents is called if there are no events to process.

If there are no events to process when do_events is called, the class will wait for the amount of time specified here before returning. The default value is 20.

UseInternalSecurityAPI:   Tells the class whether or not to use the system security libraries or an internal implementation.

When set to False, the class will use the system security libraries by default to perform cryptographic functions where applicable.

Setting this setting to True tells the class 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.

To use the system security libraries for Linux, OpenSSL support must be enabled. For more information on how to enable OpenSSL, please refer to the OpenSSL Notes section.

TCPServer Errors

TCPServer Errors

100   You cannot change the remote_port at this time. A connection is in progress.
101   You cannot change the remote_host at this time. A connection is in progress.
102   The remote_host address is invalid (0.0.0.0).
104   TCPServer is already listening.
106   Cannot change local_port when TCPServer is listening.
107   Cannot change local_host when TCPServer is listening.
108   Cannot change MaxConnections when TCPServer is listening.
112   You cannot change MaxLineLength at this time. A connection is in progress.
116   remote_port 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 non-socket.
10039   [10039] Destination address required.
10040   [10040] Message too long.
10041   [10041] Protocol wrong type for socket.
10042   [10042] Bad protocol option.
10043   [10043] Protocol not supported.
10044   [10044] Socket type not supported.
10045   [10045] Operation not supported on socket.
10046   [10046] Protocol family not supported.
10047   [10047] Address family not supported by protocol family.
10048   [10048] Address already in use.
10049   [10049] Can't 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] Can't send after socket shutdown.
10059   [10059] Too many references, can't splice.
10060   [10060] Connection timed out.
10061   [10061] Connection refused.
10062   [10062] Too many levels of symbolic links.
10063   [10063] File name too long.
10064   [10064] Host is down.
10065   [10065] No route to host.
10066   [10066] Directory 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 not loaded yet.
11001   [11001] Host not found.
11002   [11002] Non-authoritative 'Host not found' (try again or check DNS setup).
11003   [11003] Non-recoverable errors: FORMERR, REFUSED, NOTIMP.
11004   [11004] Valid name, no data record (check DNS setup).