# TCPServer Class

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

```text
class ipworks.TCPServer
```

## Remarks

The TCPServer Class supports both plaintext and Secure Sockets Layer/Transport Layer Security (SSL/TLS) connections. When connecting over Secure Sockets Layer/Transport Layer Security (SSL/TLS) the on_ssl_server_authentication event allows you to check the server identity and other security attributes. The [on_ssl_status](#on_ssl_status-event) event provides information about the SSL handshake. Additional SSL-related settings are also supported through the [config](#config-method) method. The **SSLCert** properties are used to select a certificate for the server.

NOTE: A valid certificate MUST be selected before the server can function.

TCPServer is the server complement of TCPClient, which is used to create client applications. They share a common design philosophy and interface. We expect you will find TCPServer as easy to use as TCPClient.

By default, each instance of TCPServer can handle up to 1,000 simultaneous incoming connections. This number may be increased up to 100,000 or decreased to a lower value by using the [MaxConnections](#MaxConnections) configuration setting.

The connections are identified by a *ConnectionId*, an Id generated by the component to identify each connection. This Id is unique to each connection. TCPServer's events also have *ConnectionId* as a parameter to identify the connection they relate to.

Our main goal in designing TCPServer was to make it easy to use without sacrificing performance. The class has a minimum number of properties, and six events: [on_connection_request](#on_connection_request-event), [on_connected](#on_connected-event), [on_data_in](#on_data_in-event), [on_disconnected](#on_disconnected-event), [on_ready_to_send](#on_ready_to_send-event), and [on_error](#on_error-event).

TCPServer can start to listen on a port by setting the [listening](#listening-property) property to True. When a remote host asks for a connection, the [on_connection_request](#on_connection_request-event) event is fired. At that point, the connection can either be accepted or rejected. If the connection is accepted, a *ConnectionId* is assigned, and communication can start. From this point on, the operation is very similar to TCPClient. Data are sent by assigning the data string to the *Text* parameter of the [send](#send-method) method. The address and port of the incoming connection can be found by querying the [remote_host](#remote_host-property) and [remote_port](#remote_port-property) properties.

NOTE: Server components are designed to process events as they occur. To ensure that events are processed in a timely manner, [do_events](#do_events-method) 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_count](#connection_count-property) | The number of records in the arrays. |
| [accept_data](#accept_data-property) | This property indicates whether data reception is currently enabled. |
| [bytes_sent](#bytes_sent-property) | This property shows how many bytes were sent after calling Send or SendBytes . |
| [connected](#connected-property) | This property indicates the status of individual connections. |
| [connection_id](#connection_id-property) | This property contains an identifier generated by the class to identify each connection. |
| [eol](#eol-property) | The EOL property is used to define boundaries in the input stream using the value of the property. |
| [idle_timeout](#idle_timeout-property) | This property contains the idle timeout for this connection. |
| [local_address](#local_address-property) | This property shows the IP address of the interface through which the connection is passing. |
| [ready_to_send](#ready_to_send-property) | This property indicates whether the class is ready to send data. |
| [record_length](#record_length-property) | This property holds the current record length set by ChangeRecordLength . |
| [remote_host](#remote_host-property) | This property shows the IP address of the remote host through which the connection is coming. |
| [remote_port](#remote_port-property) | This property shows the Transmission Control Protocol (TCP) port on the remote host through which the connection is coming. |
| [single_line_mode](#single_line_mode-property) | This property shows the special mode for line-oriented protocols. |
| [timeout](#timeout-property) | This property specifies a timeout for the class. |
| [user_data](#user_data-property) | The UserData property holds connection-specific user-specified data. |
| [connection_backlog](#connection_backlog-property) | This property includes the maximum number of pending connections maintained by the Transmission Control Protocol (TCP)/IP subsystem. |
| [default_eol](#default_eol-property) | This property includes a default end-of-line (EOL) value to be used by incoming connections. |
| [default_idle_timeout](#default_idle_timeout-property) | This property includes the default idle timeout for inactive clients. |
| [default_max_line_length](#default_max_line_length-property) | The property includes the default maximum line length value for inbound connections. |
| [default_single_line_mode](#default_single_line_mode-property) | This property tells the class whether or not to treat new connections as line oriented. |
| [default_timeout](#default_timeout-property) | This property includes an initial timeout value to be used by incoming connections. |
| [keep_alive](#keep_alive-property) | When True, KEEPALIVE packets are enabled (for long connections). |
| [linger](#linger-property) | When set to True, connections are terminated gracefully. |
| [listening](#listening-property) | This property indicates whether the class is listening for incoming connections on LocalPort. |
| [local_host](#local_host-property) | The name of the local host or user-assigned IP interface through which connections are initiated or accepted. |
| [local_port](#local_port-property) | This property includes the Transmission Control Protocol (TCP) port in the local host where the class listens. |
| [ssl_authenticate_clients](#ssl_authenticate_clients-property) | If set to True, the server asks the client(s) for a certificate. |
| [ssl_cert_effective_date](#ssl_cert_effective_date-property) | The date on which this certificate becomes valid. |
| [ssl_cert_encoded](#ssl_cert_encoded-property) | The certificate (PEM/Base64 encoded). |
| [ssl_cert_expiration_date](#ssl_cert_expiration_date-property) | The date on which the certificate expires. |
| [ssl_cert_extended_key_usage](#ssl_cert_extended_key_usage-property) | A comma-delimited list of extended key usage identifiers. |
| [ssl_cert_fingerprint](#ssl_cert_fingerprint-property) | The hex-encoded, 16-byte MD5 fingerprint of the certificate. |
| [ssl_cert_fingerprint_sha1](#ssl_cert_fingerprint_sha1-property) | The hex-encoded, 20-byte SHA-1 fingerprint of the certificate. |
| [ssl_cert_fingerprint_sha256](#ssl_cert_fingerprint_sha256-property) | The hex-encoded, 32-byte SHA-256 fingerprint of the certificate. |
| [ssl_cert_issuer](#ssl_cert_issuer-property) | The issuer of the certificate. |
| [ssl_cert_private_key](#ssl_cert_private_key-property) | The private key of the certificate (if available). |
| [ssl_cert_private_key_available](#ssl_cert_private_key_available-property) | Whether a PrivateKey is available for the selected certificate. |
| [ssl_cert_private_key_container](#ssl_cert_private_key_container-property) | The name of the PrivateKey container for the certificate (if available). |
| [ssl_cert_public_key](#ssl_cert_public_key-property) | The public key of the certificate. |
| [ssl_cert_public_key_algorithm](#ssl_cert_public_key_algorithm-property) | The textual description of the certificate's public key algorithm. |
| [ssl_cert_public_key_length](#ssl_cert_public_key_length-property) | The length of the certificate's public key (in bits). |
| [ssl_cert_serial_number](#ssl_cert_serial_number-property) | The serial number of the certificate encoded as a string. |
| [ssl_cert_signature_algorithm](#ssl_cert_signature_algorithm-property) | The text description of the certificate's signature algorithm. |
| [ssl_cert_store](#ssl_cert_store-property) | The name of the certificate store for the client certificate. |
| [ssl_cert_store_password](#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. |
| [ssl_cert_store_type](#ssl_cert_store_type-property) | The type of certificate store for this certificate. |
| [ssl_cert_subject](#ssl_cert_subject-property) | The subject of the certificate used for client authentication. |
| [ssl_cert_subject_alt_names](#ssl_cert_subject_alt_names-property) | Comma-separated lists of alternative subject names for the certificate. |
| [ssl_cert_thumbprint_md5](#ssl_cert_thumbprint_md5-property) | The MD5 hash of the certificate. |
| [ssl_cert_thumbprint_sha1](#ssl_cert_thumbprint_sha1-property) | The SHA-1 hash of the certificate. |
| [ssl_cert_thumbprint_sha256](#ssl_cert_thumbprint_sha256-property) | The SHA-256 hash of the certificate. |
| [ssl_cert_usage](#ssl_cert_usage-property) | The text description of UsageFlags . |
| [ssl_cert_usage_flags](#ssl_cert_usage_flags-property) | The flags that show intended use for the certificate. |
| [ssl_cert_version](#ssl_cert_version-property) | The certificate's version number. |
| [ssl_enabled](#ssl_enabled-property) | This property indicates whether Transport Layer Security/Secure Sockets Layer (TLS/SSL) is enabled. |
| [ssl_provider](#ssl_provider-property) | The Secure Sockets Layer/Transport Layer Security (SSL/TLS) implementation to use. |
| [ssl_start_mode](#ssl_start_mode-property) | This property determines how the class starts the Secure Sockets Layer (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_length](#change_record_length-method) | This method changes the length of received data records. |
| [config](#config-method) | Sets or retrieves a configuration setting. |
| [disconnect](#disconnect-method) | This method disconnects the specified client. |
| [do_events](#do_events-method) | This method processes events from the internal message queue. |
| [interrupt](#interrupt-method) | This method interrupts a synchronous send to the remote host. |
| [pause_data](#pause_data-method) | This method pauses data reception. |
| [process_data](#process_data-method) | This method reenables data reception after a call to PauseData . |
| [reset](#reset-method) | This method will reset the class. |
| [send](#send-method) | This method sends binary data to the specified client. |
| [send_bytes](#send_bytes-method) | This method sends binary data to the specified client. |
| [send_file](#send_file-method) | This method sends the file to the remote host. |
| [send_line](#send_line-method) | This method sends a string followed by a new line. |
| [send_text](#send_text-method) | This method sends text to the specified client. |
| [shutdown](#shutdown-method) | This method shuts down the server. |
| [start_listening](#start_listening-method) | This method starts listening for incoming connections. |
| [start_ssl](#start_ssl-method) | This method starts the Secure Sockets Layer (SSL) negotiation on a connection. |
| [stop_listening](#stop_listening-method) | This 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_connected](#on_connected-event) | This event is fired immediately after a connection completes (or fails). |
| [on_connection_request](#on_connection_request-event) | This event is fired when a request for connection comes from a remote host. |
| [on_data_in](#on_data_in-event) | This event is fired when data come in. |
| [on_disconnected](#on_disconnected-event) | This event is fired when a connection is closed. |
| [on_error](#on_error-event) | This event fires information about errors during data delivery. |
| [on_ready_to_send](#on_ready_to_send-event) | This event is fired when the class is ready to send data. |
| [on_ssl_client_authentication](#on_ssl_client_authentication-event) | This event is fired when the client presents its credentials to the server. |
| [on_ssl_connection_request](#on_ssl_connection_request-event) | This event fires when a Secure Sockets Layer (SSL) connection is requested. |
| [on_ssl_status](#on_ssl_status-event) | This 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.*

|  |  |
| --- | --- |
| [AllowedClients](#AllowedClients) | A comma-separated list of host names or IP addresses that can access the class. |
| [BindExclusively](#BindExclusively) | Whether or not the class considers a local port reserved for exclusive use. |
| [BlockedClients](#BlockedClients) | A comma-separated list of host names or IP addresses that cannot access the class. |
| [ConnectionUID](#ConnectionUID) | The unique connectionId for a connection. |
| [DefaultConnectionTimeout](#DefaultConnectionTimeout) | The inactivity timeout applied to the SSL handshake. |
| [InBufferSize](#InBufferSize) | The size in bytes of the incoming queue of the socket. |
| [KeepAliveInterval](#KeepAliveInterval) | The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received. |
| [KeepAliveRetryCount](#KeepAliveRetryCount) | The number of keep-alive packets to be sent before the remotehost is considered disconnected. |
| [KeepAliveTime](#KeepAliveTime) | The inactivity time in milliseconds before a TCP keep-alive packet is sent. |
| [MaxConnections](#MaxConnections) | The maximum number of connections available. |
| [MaxReadTime](#MaxReadTime) | The maximum time spent reading data from each connection. |
| [OutBufferSize](#OutBufferSize) | The size in bytes of the outgoing queue of the socket. |
| [TcpNoDelay](#TcpNoDelay) | Whether or not to delay when sending packets. |
| [UseIOCP](#UseIOCP) | Whether to use the completion port I/O model. |
| [UseIPv6](#UseIPv6) | Whether to use IPv6. |
| [UseWindowsMessages](#UseWindowsMessages) | Whether to use the WSAAsyncSelect I/O model. |
| [LogSSLPackets](#LogSSLPackets) | Controls whether SSL packets are logged when using the internal security API. |
| [OpenSSLCADir](#OpenSSLCADir) | The path to a directory containing CA certificates. |
| [OpenSSLCAFile](#OpenSSLCAFile) | Name of the file containing the list of CA's trusted by your application. |
| [OpenSSLCipherList](#OpenSSLCipherList) | A string that controls the ciphers to be used by SSL. |
| [OpenSSLPrngSeedData](#OpenSSLPrngSeedData) | The data to seed the pseudo random number generator (PRNG). |
| [ReuseSSLSession](#ReuseSSLSession) | Determines if the SSL session is reused. |
| [SSLCACertFilePaths](#SSLCACertFilePaths) | The paths to CA certificate files on Unix/Linux. |
| [SSLCACerts](#SSLCACerts) | A newline separated list of CA certificates to be included when performing an SSL handshake. |
| [SSLCheckCRL](#SSLCheckCRL) | Whether to check the Certificate Revocation List for the server certificate. |
| [SSLCheckOCSP](#SSLCheckOCSP) | Whether to use OCSP to check the status of the server certificate. |
| [SSLCipherStrength](#SSLCipherStrength) | The minimum cipher strength used for bulk encryption. |
| [SSLClientCACerts](#SSLClientCACerts) | A newline separated list of CA certificates to use during SSL client certificate validation. |
| [SSLEnabledCipherSuites](#SSLEnabledCipherSuites) | The cipher suite to be used in an SSL negotiation. |
| [SSLEnabledProtocols](#SSLEnabledProtocols) | Used to enable/disable the supported security protocols. |
| [SSLEnableRenegotiation](#SSLEnableRenegotiation) | Whether the renegotiation_info SSL extension is supported. |
| [SSLIncludeCertChain](#SSLIncludeCertChain) | Whether the entire certificate chain is included in the SSLServerAuthentication event. |
| [SSLKeyLogFile](#SSLKeyLogFile) | The location of a file where per-session secrets are written for debugging purposes. |
| [SSLNegotiatedCipher](#SSLNegotiatedCipher) | Returns the negotiated cipher suite. |
| [SSLNegotiatedCipherStrength](#SSLNegotiatedCipherStrength) | Returns the negotiated cipher suite strength. |
| [SSLNegotiatedCipherSuite](#SSLNegotiatedCipherSuite) | Returns the negotiated cipher suite. |
| [SSLNegotiatedKeyExchange](#SSLNegotiatedKeyExchange) | Returns the negotiated key exchange algorithm. |
| [SSLNegotiatedKeyExchangeStrength](#SSLNegotiatedKeyExchangeStrength) | Returns the negotiated key exchange algorithm strength. |
| [SSLNegotiatedVersion](#SSLNegotiatedVersion) | Returns the negotiated protocol version. |
| [SSLSecurityFlags](#SSLSecurityFlags) | Flags that control certificate verification. |
| [SSLServerCACerts](#SSLServerCACerts) | A newline separated list of CA certificates to use during SSL server certificate validation. |
| [TLS12SignatureAlgorithms](#TLS12SignatureAlgorithms) | Defines the allowed TLS 1.2 signature algorithms when SSLProvider is set to Internal. |
| [TLS12SupportedGroups](#TLS12SupportedGroups) | The supported groups for ECC. |
| [TLS13KeyShareGroups](#TLS13KeyShareGroups) | The groups for which to pregenerate key shares. |
| [TLS13SignatureAlgorithms](#TLS13SignatureAlgorithms) | The allowed certificate signature algorithms. |
| [TLS13SupportedGroups](#TLS13SupportedGroups) | The supported groups for (EC)DHE key exchange. |
| [BuildInfo](#BuildInfo) | Information about the product's build. |
| [CodePage](#CodePage) | The system code page used for Unicode to Multibyte translations. |
| [LicenseInfo](#LicenseInfo) | Information about the current license. |
| [MaskSensitiveData](#MaskSensitiveData) | Whether sensitive data is masked in log messages. |
| [ProcessIdleEvents](#ProcessIdleEvents) | Whether the class uses its internal event loop to process events when the main thread is idle. |
| [SelectWaitMillis](#SelectWaitMillis) | The length of time in milliseconds the class will wait when DoEvents is called if there are no events to process. |
| [UseInternalSecurityAPI](#UseInternalSecurityAPI) | Whether or not to use the system security libraries or an internal implementation. |

# connection_count property

The number of records in the arrays.

## Syntax

```text
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:

- [accept_data](#accept_data-property)
- [bytes_sent](#bytes_sent-property)
- [connected](#connected-property)
- [connection_id](#connection_id-property)
- [eol](#eol-property)
- [idle_timeout](#idle_timeout-property)
- [local_address](#local_address-property)
- [ready_to_send](#ready_to_send-property)
- [record_length](#record_length-property)
- [remote_host](#remote_host-property)
- [remote_port](#remote_port-property)
- [single_line_mode](#single_line_mode-property)
- [ssl_cert_effective_date](#ssl_cert_effective_date-property)
- [ssl_cert_encoded](#ssl_cert_encoded-property)
- [ssl_cert_expiration_date](#ssl_cert_expiration_date-property)
- [ssl_cert_extended_key_usage](#ssl_cert_extended_key_usage-property)
- [ssl_cert_fingerprint](#ssl_cert_fingerprint-property)
- [ssl_cert_fingerprint_sha1](#ssl_cert_fingerprint_sha1-property)
- [ssl_cert_fingerprint_sha256](#ssl_cert_fingerprint_sha256-property)
- [ssl_cert_issuer](#ssl_cert_issuer-property)
- [ssl_cert_private_key](#ssl_cert_private_key-property)
- [ssl_cert_private_key_available](#ssl_cert_private_key_available-property)
- [ssl_cert_private_key_container](#ssl_cert_private_key_container-property)
- [ssl_cert_public_key](#ssl_cert_public_key-property)
- [ssl_cert_public_key_algorithm](#ssl_cert_public_key_algorithm-property)
- [ssl_cert_public_key_length](#ssl_cert_public_key_length-property)
- [ssl_cert_serial_number](#ssl_cert_serial_number-property)
- [ssl_cert_signature_algorithm](#ssl_cert_signature_algorithm-property)
- [ssl_cert_store](#ssl_cert_store-property)
- [ssl_cert_store_password](#ssl_cert_store_password-property)
- [ssl_cert_store_type](#ssl_cert_store_type-property)
- [ssl_cert_subject](#ssl_cert_subject-property)
- [ssl_cert_subject_alt_names](#ssl_cert_subject_alt_names-property)
- [ssl_cert_thumbprint_md5](#ssl_cert_thumbprint_md5-property)
- [ssl_cert_thumbprint_sha1](#ssl_cert_thumbprint_sha1-property)
- [ssl_cert_thumbprint_sha256](#ssl_cert_thumbprint_sha256-property)
- [ssl_cert_usage](#ssl_cert_usage-property)
- [ssl_cert_usage_flags](#ssl_cert_usage_flags-property)
- [ssl_cert_version](#ssl_cert_version-property)
- [timeout](#timeout-property)
- [user_data](#user_data-property)

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

This property is read-only.

# accept_data property

This property indicates whether data reception is currently enabled.

## Syntax

```text
def get_accept_data(connection_id: int) -> bool: ...
```

## Default Value

TRUE

## Remarks

This property indicates whether data reception is currently enabled. When *False*, data reception is disabled and the ondatain event will not fire for the connection. Use the pausedata and processdata methods to pause and resume data reception.

The *connection_id* parameter specifies the index of the item in the array. The size of the array is controlled by the [connection_count](#connection_count-property) property.

This property is read-only.

# bytes_sent property

This property shows how many bytes were sent after calling Send or SendBytes .

## Syntax

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

## Default Value

0

## Remarks

This property shows how many bytes were sent after calling send or sendbytes. Please see send or sendbytes for more information.

NOTE: This property will always return 0 when the class is operating in the synchronous mode (i.e., the [timeout](#TCPServerpTimeout) 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](#connection_count-property) property.

This property is read-only.

# connected property

This property indicates the status of individual connections.

## Syntax

```text
def get_connected(connection_id: int) -> bool: ...
```

## Default Value

FALSE

## Remarks

This property indicates the status of individual connections.

When *True*, the connection is established. Use the disconnect method to disconnect an existing 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](#connection_count-property) property.

This property is read-only.

# connection_id property

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

## Syntax

```text
def get_connection_id(connection_id: int) -> int: ...
```

## Default Value

0

## 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](#connection_count-property) property.

This property is read-only.

# eol property

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

## Syntax

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

## Default Value

""

## Remarks

The [eol](#TCPServerpEOL) property is used to define boundaries in the input stream using the value of the property.

The [eol](#TCPServerpEOL) 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](#TCPServerpEOL) 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](#connection_count-property) property.

# idle_timeout property

This property contains the idle timeout for this connection.

## Syntax

```text
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](#connection_count-property) property.

# local_address property

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

## Syntax

```text
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](#TCPServerpLocalAddress) 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](#connection_count-property) property.

This property is read-only.

# ready_to_send property

This property indicates whether the class is ready to send data.

## Syntax

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

## Default Value

FALSE

## Remarks

This property indicates whether the class is ready to send data.

This is *True* after a client connects but will become *False* after a failed call to send or sendbytes. After a failed call to send or sendbytes, the 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](#connection_count-property) property.

This property is read-only.

# record_length property

This property holds the current record length set by ChangeRecordLength .

## Syntax

```text
def get_record_length(connection_id: int) -> int: ...
```

## Default Value

0

## Remarks

This property holds the current record length set by changerecordlength. When this value is a positive number, the class will accumulate data until [recordlength](#TCPServerpRecordLength) is reached and only then will fire the ondatain event with the data of length [recordlength](#TCPServerpRecordLength). This allows data to be received as records of known length. This value can be changed at any time by calling changerecordlength, including within the ondatain event.

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

The *connection_id* parameter specifies the index of the item in the array. The size of the array is controlled by the [connection_count](#connection_count-property) property.

This property is read-only.

# remote_host property

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

## Syntax

```text
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](#connection_count-property) 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

```text
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](#connection_count-property) property.

This property is read-only.

# single_line_mode property

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

## Syntax

```text
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](#connection_count-property) property.

# timeout property

This property specifies a timeout for the class.

## Syntax

```text
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](#TCPServerpTimeout) property is set to 0, all operations return immediately, potentially failing with a *WOULDBLOCK* error if data cannot be sent immediately.

If [timeout](#TCPServerpTimeout) 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](#TCPServerpTimeout) 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.

NOTE: By default, all timeouts are *inactivity timeouts*, that is, the timeout period is extended by timeout seconds when any amount of data is successfully sent or received.

The default value for the [timeout](#TCPServerpTimeout) 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](#connection_count-property) property.

# user_data property

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

## Syntax

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

## Default Value

""

## Remarks

The [userdata](#TCPServerpUserData) 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](#connection_count-property) property.

# connection_backlog property

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

## Syntax

```text
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.

# default_eol property

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

## Syntax

```text
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

```text
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](#do_events-method) 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

```text
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

```text
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

```text
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

```text
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

```text
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

This property indicates whether the class is listening for incoming connections on LocalPort.

## Syntax

```text
def get_listening() -> bool: ...
listening = property(get_listening, None)
```

## Default Value

FALSE

## Remarks

This property indicates whether the class is listening for connections on the port specified by the [local_port](#local_port-property) property. Use the [start_listening](#start_listening-method) and [stop_listening](#stop_listening-method) methods to control whether the class is listening.

This property is read-only.

# local_host property

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

## Syntax

```text
def get_local_host() -> str: ...
def set_local_host(value: str) -> None: ...
local_host = property(get_local_host, set_local_host)
```

## Default Value

""

## Remarks

This property contains the name of the local host as obtained by the *gethostname()* system call, or if the user has assigned an IP address, the value of that address.

In multihomed hosts (machines with more than one IP interface) setting LocalHost to the IP address of an interface will make the class initiate connections (or accept in the case of server classes) only through that interface. It is recommended to provide an IP address rather than a hostname when setting this property to ensure the desired interface is used.

If the 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 multihomed 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

```text
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](#listening-property) property).

The service port is not shared among servers so two classes 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

```text
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](#on_ssl_client_authentication-event) event. Please refer to the documentation of the [on_ssl_client_authentication](#on_ssl_client_authentication-event) event for details.

# ssl_cert_effective_date property

The date on which this certificate becomes valid.

## Syntax

```text
def get_ssl_cert_effective_date() -> str: ...
ssl_cert_effective_date = property(get_ssl_cert_effective_date, None)
```

## Default Value

""

## Remarks

The date on which this certificate becomes valid. Before this date, it is not valid. The date is localized to the system's time zone. The following example illustrates the format of an encoded date:

23-Jan-2000 15:00:00.

This property is read-only.

# ssl_cert_encoded property

The certificate (PEM/Base64 encoded).

## Syntax

```text
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

The certificate (PEM/Base64 encoded). This property is used to assign a specific certificate. The [ssl_cert_store](#ssl_cert_store-property) and [ssl_cert_subject](#ssl_cert_subject-property) properties also may be used to specify a certificate.

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

# ssl_cert_expiration_date property

The date on which the certificate expires.

## Syntax

```text
def get_ssl_cert_expiration_date() -> str: ...
ssl_cert_expiration_date = property(get_ssl_cert_expiration_date, None)
```

## Default Value

""

## Remarks

The date on which the certificate expires. After this date, the certificate will no longer be valid. The date is localized to the system's time zone. The following example illustrates the format of an encoded date:

23-Jan-2001 15:00:00.

This property is read-only.

# ssl_cert_extended_key_usage property

A comma-delimited list of extended key usage identifiers.

## Syntax

```text
def get_ssl_cert_extended_key_usage() -> str: ...
ssl_cert_extended_key_usage = property(get_ssl_cert_extended_key_usage, None)
```

## Default Value

""

## Remarks

A comma-delimited list of extended key usage identifiers. These are the same as ASN.1 object identifiers (OIDs).

This property is read-only.

# ssl_cert_fingerprint property

The hex-encoded, 16-byte MD5 fingerprint of the certificate.

## Syntax

```text
def get_ssl_cert_fingerprint() -> str: ...
ssl_cert_fingerprint = property(get_ssl_cert_fingerprint, None)
```

## Default Value

""

## Remarks

The hex-encoded, 16-byte MD5 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys.

The following example illustrates the format: *bc:2a:72:af:fe:58:17:43:7a:5f:ba:5a:7c:90:f7:02*

This property is read-only.

# ssl_cert_fingerprint_sha1 property

The hex-encoded, 20-byte SHA-1 fingerprint of the certificate.

## Syntax

```text
def get_ssl_cert_fingerprint_sha1() -> str: ...
ssl_cert_fingerprint_sha1 = property(get_ssl_cert_fingerprint_sha1, None)
```

## Default Value

""

## Remarks

The hex-encoded, 20-byte SHA-1 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys.

The following example illustrates the format: *30:7b:fa:38:65:83:ff:da:b4:4e:07:3f:17:b8:a4:ed:80:be:ff:84*

This property is read-only.

# ssl_cert_fingerprint_sha256 property

The hex-encoded, 32-byte SHA-256 fingerprint of the certificate.

## Syntax

```text
def get_ssl_cert_fingerprint_sha256() -> str: ...
ssl_cert_fingerprint_sha256 = property(get_ssl_cert_fingerprint_sha256, None)
```

## Default Value

""

## Remarks

The hex-encoded, 32-byte SHA-256 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys.

The following example illustrates the format: *6a:80:5c:33:a9:43:ea:b0:96:12:8a:64:96:30:ef:4a:8a:96:86:ce:f4:c7:be:10:24:8e:2b:60:9e:f3:59:53*

This property is read-only.

# ssl_cert_issuer property

The issuer of the certificate.

## Syntax

```text
def get_ssl_cert_issuer() -> str: ...
ssl_cert_issuer = property(get_ssl_cert_issuer, None)
```

## Default Value

""

## Remarks

The issuer of the certificate. This property contains a string representation of the name of the issuing authority for the certificate.

This property is read-only.

# ssl_cert_private_key property

The private key of the certificate (if available).

## Syntax

```text
def get_ssl_cert_private_key() -> str: ...
ssl_cert_private_key = property(get_ssl_cert_private_key, None)
```

## Default Value

""

## Remarks

The private key of the certificate (if available). The key is provided as PEM/Base64-encoded data.

NOTE: The [ssl_cert_private_key](#ssl_cert_private_key-property) may be available but not exportable. In this case, [ssl_cert_private_key](#ssl_cert_private_key-property) returns an empty string.

This property is read-only.

# ssl_cert_private_key_available property

Whether a PrivateKey is available for the selected certificate.

## Syntax

```text
def get_ssl_cert_private_key_available() -> bool: ...
ssl_cert_private_key_available = property(get_ssl_cert_private_key_available, None)
```

## Default Value

FALSE

## Remarks

Whether a [ssl_cert_private_key](#ssl_cert_private_key-property) is available for the selected certificate. If [ssl_cert_private_key_available](#ssl_cert_private_key_available-property) is True, the certificate may be used for authentication purposes (e.g., server authentication).

This property is read-only.

# ssl_cert_private_key_container property

The name of the PrivateKey container for the certificate (if available).

## Syntax

```text
def get_ssl_cert_private_key_container() -> str: ...
ssl_cert_private_key_container = property(get_ssl_cert_private_key_container, None)
```

## Default Value

""

## Remarks

The name of the [ssl_cert_private_key](#ssl_cert_private_key-property) container for the certificate (if available). This functionality is available only on Windows platforms.

This property is read-only.

# ssl_cert_public_key property

The public key of the certificate.

## Syntax

```text
def get_ssl_cert_public_key() -> str: ...
ssl_cert_public_key = property(get_ssl_cert_public_key, None)
```

## Default Value

""

## Remarks

The public key of the certificate. The key is provided as PEM/Base64-encoded data.

This property is read-only.

# ssl_cert_public_key_algorithm property

The textual description of the certificate's public key algorithm.

## Syntax

```text
def get_ssl_cert_public_key_algorithm() -> str: ...
ssl_cert_public_key_algorithm = property(get_ssl_cert_public_key_algorithm, None)
```

## Default Value

""

## Remarks

The textual description of the certificate's public key algorithm. The property contains either the name of the algorithm (e.g., "RSA" or "RSA_DH") or an object identifier (OID) string representing the algorithm.

This property is read-only.

# ssl_cert_public_key_length property

The length of the certificate's public key (in bits).

## Syntax

```text
def get_ssl_cert_public_key_length() -> int: ...
ssl_cert_public_key_length = property(get_ssl_cert_public_key_length, None)
```

## Default Value

0

## Remarks

The length of the certificate's public key (in bits). Common values are 512, 1024, and 2048.

This property is read-only.

# ssl_cert_serial_number property

The serial number of the certificate encoded as a string.

## Syntax

```text
def get_ssl_cert_serial_number() -> str: ...
ssl_cert_serial_number = property(get_ssl_cert_serial_number, None)
```

## Default Value

""

## Remarks

The serial number of the certificate encoded as a string. The number is encoded as a series of hexadecimal digits, with each pair representing a byte of the serial number.

This property is read-only.

# ssl_cert_signature_algorithm property

The text description of the certificate's signature algorithm.

## Syntax

```text
def get_ssl_cert_signature_algorithm() -> str: ...
ssl_cert_signature_algorithm = property(get_ssl_cert_signature_algorithm, None)
```

## Default Value

""

## Remarks

The text description of the certificate's signature algorithm. The property contains either the name of the algorithm (e.g., "RSA" or "RSA_MD5RSA") or an object identifier (OID) string representing the algorithm.

This property is read-only.

# ssl_cert_store property

The name of the certificate store for the client certificate.

## Syntax

```text
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

The name of the certificate store for the client certificate.

The [ssl_cert_store_type](#ssl_cert_store_type-property) property denotes the type of the certificate store specified by [ssl_cert_store](#ssl_cert_store-property). If the store is password-protected, specify the password in [ssl_cert_store_password](#ssl_cert_store_password-property).

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

 Designations of certificate stores are platform dependent.

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

|  |  |
| --- | --- |
| MY | A certificate store holding personal certificates with their associated private keys. |
| CA | Certifying authority certificates. |
| ROOT | Root certificates. |

When the certificate store type is *cstPFXFile*, this property must be set to the name of the file. When the type is *cstPFXBlob*, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store).

# 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

```text
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

The type of certificate store for this certificate.

## Syntax

```text
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)
```

## Possible Values

```text
0   # User1   # Machine2   # PFXFile3   # PFXBlob4   # JKSFile5   # JKSBlob6   # PEMKeyFile7   # PEMKeyBlob8   # PublicKeyFile9   # PublicKeyBlob10   # SSHPublicKeyBlob11   # P7BFile12   # P7BBlob13   # SSHPublicKeyFile14   # PPKFile15   # PPKBlob16   # XMLFile17   # XMLBlob18   # JWKFile19   # JWKBlob20   # SecurityKey21   # BCFKSFile22   # BCFKSBlob23   # PKCS1199   # Auto
```

## Default Value

0

## Remarks

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:

```csharp
sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11,
                               @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll",
                               "123456", // PIN
                               "CN=cert_subject");
sftp.SSHUser = "test";
sftp.SSHLogon("myhost", 22);
```

```csharp
certmgr.CertStoreType = CertStoreTypes.cstPKCS11;
certmgr.OnCertList += (s, e) => {
  secKeyBlob = e.CertEncoded;
};
certmgr.CertStore = @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll";
certmgr.CertStorePassword = "123456"; // PIN
certmgr.ListStoreCertificates();

sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11, secKeyBlob, "123456", "*");
sftp.SSHUser = "test";
sftp.SSHLogon("myhost", 22);
```

|  |  |
| --- | --- |
| 0 (cstUser - default) | For Windows, this specifies that the certificate store is a certificate store owned by the current user. NOTE: This store type is not available in Java. |
| 1 (cstMachine) | For Windows, this specifies that the certificate store is a machine store. NOTE: This store type is not available in Java. |
| 2 (cstPFXFile) | The certificate store is the name of a PFX (PKCS#12) file containing certificates. |
| 3 (cstPFXBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in PFX (PKCS#12) format. |
| 4 (cstJKSFile) | The certificate store is the name of a Java Key Store (JKS) file containing certificates. NOTE: This store type is only available in Java. |
| 5 (cstJKSBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in Java Key Store (JKS) format. NOTE: This store type is only available in Java. |
| 6 (cstPEMKeyFile) | The certificate store is the name of a PEM-encoded file that contains a private key and an optional certificate. |
| 7 (cstPEMKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains a private key and an optional certificate. |
| 8 (cstPublicKeyFile) | The certificate store is the name of a file that contains a PEM- or DER-encoded public key certificate. |
| 9 (cstPublicKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains a PEM- or DER-encoded public key certificate. |
| 10 (cstSSHPublicKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains an SSH-style public key. |
| 11 (cstP7BFile) | The certificate store is the name of a PKCS#7 file containing certificates. |
| 12 (cstP7BBlob) | The certificate store is a string (binary) representing a certificate store in PKCS#7 format. |
| 13 (cstSSHPublicKeyFile) | The certificate store is the name of a file that contains an SSH-style public key. |
| 14 (cstPPKFile) | The certificate store is the name of a file that contains a PPK (PuTTY Private Key). |
| 15 (cstPPKBlob) | The certificate store is a string (binary) that contains a PPK (PuTTY Private Key). |
| 16 (cstXMLFile) | The certificate store is the name of a file that contains a certificate in XML format. |
| 17 (cstXMLBlob) | The certificate store is a string that contains a certificate in XML format. |
| 18 (cstJWKFile) | The certificate store is the name of a file that contains a JWK (JSON Web Key). |
| 19 (cstJWKBlob) | The certificate store is a string that contains a JWK (JSON Web Key). |
| 21 (cstBCFKSFile) | The certificate store is the name of a file that contains a BCFKS (Bouncy Castle FIPS Key Store). NOTE: This store type is only available in Java and .NET. |
| 22 (cstBCFKSBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in BCFKS (Bouncy Castle FIPS Key Store) format. NOTE: This store type is only available in Java and .NET. |
| 23 (cstPKCS11) | The certificate is present on a physical security key accessible via a PKCS#11 interface. To use a security key, create a new [Certificate](#Type_Certificate) object and pass cstPKCS11 as the [ssl_cert_store_type](#ssl_cert_store_type-property), the full path of the PKCS#11 DLL as the [ssl_cert_store](#ssl_cert_store-property), and the PIN as the [ssl_cert_store_password](#ssl_cert_store_password-property). Code Example. SSH Authentication with Security Key (without CertMgr): Alternatively, collect the necessary data using the [CertMgr](#CertMgr) class by calling the [list_store_certificates](#CertMgr_m_ListStoreCertificates) method after setting the corresponding properties accordingly. The certificate information returned in the [on_cert_list](#CertMgr_e_CertList) event's CertEncoded parameter may be saved for later use. When using a certificate obtained with this approach, pass the previously saved security key information as the [ssl_cert_store](#ssl_cert_store-property) and set [ssl_cert_store_password](#ssl_cert_store_password-property) to the PIN. Code Example. SSH Authentication with Security Key (with CertMgr): |
| 99 (cstAuto) | The store type is automatically detected from the input data. This setting may be used with both public and private keys and can detect any of the supported formats automatically. |

# ssl_cert_subject property

The subject of the certificate used for client authentication.

## Syntax

```text
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

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=example@email.com". Common fields and their meanings are as follows:

| Field | Meaning |
| --- | --- |
| CN | Common Name. This is commonly a hostname like www.server.com. |
| O | Organization |
| OU | Organizational Unit |
| L | Locality |
| S | State |
| C | Country |
| E | Email Address |

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

# ssl_cert_subject_alt_names property

Comma-separated lists of alternative subject names for the certificate.

## Syntax

```text
def get_ssl_cert_subject_alt_names() -> str: ...
ssl_cert_subject_alt_names = property(get_ssl_cert_subject_alt_names, None)
```

## Default Value

""

## Remarks

Comma-separated lists of alternative subject names for the certificate.

This property is read-only.

# ssl_cert_thumbprint_md5 property

The MD5 hash of the certificate.

## Syntax

```text
def get_ssl_cert_thumbprint_md5() -> str: ...
ssl_cert_thumbprint_md5 = property(get_ssl_cert_thumbprint_md5, None)
```

## Default Value

""

## Remarks

The MD5 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed.

This property is read-only.

# ssl_cert_thumbprint_sha1 property

The SHA-1 hash of the certificate.

## Syntax

```text
def get_ssl_cert_thumbprint_sha1() -> str: ...
ssl_cert_thumbprint_sha1 = property(get_ssl_cert_thumbprint_sha1, None)
```

## Default Value

""

## Remarks

The SHA-1 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed.

This property is read-only.

# ssl_cert_thumbprint_sha256 property

The SHA-256 hash of the certificate.

## Syntax

```text
def get_ssl_cert_thumbprint_sha256() -> str: ...
ssl_cert_thumbprint_sha256 = property(get_ssl_cert_thumbprint_sha256, None)
```

## Default Value

""

## Remarks

The SHA-256 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed.

This property is read-only.

# ssl_cert_usage property

The text description of UsageFlags .

## Syntax

```text
def get_ssl_cert_usage() -> str: ...
ssl_cert_usage = property(get_ssl_cert_usage, None)
```

## Default Value

""

## Remarks

The text description of [ssl_cert_usage_flags](#ssl_cert_usage_flags-property).

This value will be one or more of the following strings and will be separated by commas:

- Digital Signature
- Non-Repudiation
- Key Encipherment
- Data Encipherment
- Key Agreement
- Certificate Signing
- CRL Signing
- Encipher Only

If the provider is OpenSSL, the value is a comma-separated list of X.509 certificate extension names.

This property is read-only.

# ssl_cert_usage_flags property

The flags that show intended use for the certificate.

## Syntax

```text
def get_ssl_cert_usage_flags() -> int: ...
ssl_cert_usage_flags = property(get_ssl_cert_usage_flags, None)
```

## Default Value

0

## Remarks

The flags that show intended use for the certificate. The value of [ssl_cert_usage_flags](#ssl_cert_usage_flags-property) is a combination of the following flags:

|  |  |
| --- | --- |
| 0x80 | Digital Signature |
| 0x40 | Non-Repudiation |
| 0x20 | Key Encipherment |
| 0x10 | Data Encipherment |
| 0x08 | Key Agreement |
| 0x04 | Certificate Signing |
| 0x02 | CRL Signing |
| 0x01 | Encipher Only |

Please see the [ssl_cert_usage](#ssl_cert_usage-property) property for a text representation of [ssl_cert_usage_flags](#ssl_cert_usage_flags-property).

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

This property is read-only.

# ssl_cert_version property

The certificate's version number.

## Syntax

```text
def get_ssl_cert_version() -> str: ...
ssl_cert_version = property(get_ssl_cert_version, None)
```

## Default Value

""

## Remarks

The certificate's version number. The possible values are the strings "V1", "V2", and "V3".

This property is read-only.

# ssl_enabled property

This property indicates whether Transport Layer Security/Secure Sockets Layer (TLS/SSL) is enabled.

## Syntax

```text
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 property 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](#ssl_start_mode-property). Setting [ssl_start_mode](#ssl_start_mode-property) will automatically update this property value.

# ssl_provider property

The Secure Sockets Layer/Transport Layer Security (SSL/TLS) implementation to use.

## Syntax

```text
def get_ssl_provider() -> int: ...
def set_ssl_provider(value: int) -> None: ...
ssl_provider = property(get_ssl_provider, set_ssl_provider)
```

## Possible Values

```text
0   # Automatic1   # Platform2   # Internal
```

## 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 as follows:

|  |  |
| --- | --- |
| 0 (sslpAutomatic - default) | Automatically selects the appropriate implementation. |
| 1 (sslpPlatform) | Uses the platform/system implementation. |
| 2 (sslpInternal) | Uses the internal implementation. |

 **Additional Notes**

In most cases using the default value (Automatic) is recommended. The 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](#SSLEnabledProtocols), the class will always try and use the platform implementation. If the platform TLS 1.3 implementation is not available, the internal implementation will be used.

# ssl_start_mode property

This property determines how the class starts the Secure Sockets Layer (SSL) negotiation.

## Syntax

```text
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)
```

## Possible Values

```text
0   # Automatic1   # Implicit2   # Explicit3   # None
```

## 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 will explicitly start SSL negotiation through a protocol command such as STARTTLS. |
| 3 (sslNone - default) | No SSL negotiation; no SSL security. All communication will be in plaintext mode. |

# change_record_length method

This method changes the length of received data records.

## Syntax

```text
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 *connection_id*.

If *record_length* is set to a positive value, the class will accumulate data until *record_length* bytes of data are received and only then will fire the [on_data_in](#on_data_in-event) event with data of the specified length *record_length*. 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](#on_data_in-event) event.

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

# config method

Sets or retrieves a configuration setting.

## Syntax

```text
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](#tcpserver-config-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](#tcpserver-config-settings), you must call *Config("PROPERTY")*. The value will be returned as a string.

# disconnect method

This method disconnects the specified client.

## Syntax

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

## Remarks

Calling this method will disconnect the client specified by the *connection_id* parameter.

# do_events method

This method processes events from the internal message queue.

## Syntax

```text
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

```text
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](#send_file-method) 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

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

## Remarks

This method pauses data reception for the connection identified by *connection_id* when called. While data reception is paused, the [on_data_in](#on_data_in-event) event will not fire for the specified connection. Call [process_data](#process_data-method) to reenable data reception.

# process_data method

This method reenables data reception after a call to PauseData .

## Syntax

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

## Remarks

This method reenables data reception for the connection identified by *connection_id* after a previous call to [pause_data](#pause_data-method). When [pause_data](#pause_data-method) is called, the [on_data_in](#on_data_in-event) event will not fire for the specified connection. To reenable data reception and allow [on_data_in](#on_data_in-event) to fire, call this method.

NOTE: This method is used only after previously calling [pause_data](#pause_data-method). It does not need to be called to process incoming data by default.

# reset method

This method will reset the class.

## Syntax

```text
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

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

## Remarks

This method sends binary data to the client identified by *connection_id*. To send text, use the [send_text](#send_text-method) method instead.

 When [ws_connection_timeout](#TCPServer_p_WSConnectionTimeout) 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](#bytes_sent-property) property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the [on_ready_to_send](#on_ready_to_send-event) event before attempting to send data again.

NOTE: The [on_ready_to_send](#on_ready_to_send-event) 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

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

## Remarks

This method sends binary data to the client identified by *connection_id*. To send text, use the [send_text](#send_text-method) method instead.

 When [ws_connection_timeout](#TCPServer_p_WSConnectionTimeout) 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](#bytes_sent-property) property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the [on_ready_to_send](#on_ready_to_send-event) event before attempting to send data again.

NOTE: The [on_ready_to_send](#on_ready_to_send-event) 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

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

## Remarks

This method sends the file to the client specified by the *connection_id*.

# send_line method

This method sends a string followed by a new line.

## Syntax

```text
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](#single_line_mode-property) property for more information.

# send_text method

This method sends text to the specified client.

## Syntax

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

## Remarks

This method sends text to the client identified by *connection_id*. To send binary data, use the [send_bytes](#send_bytes-method) method instead.

 When [ws_connection_timeout](#TCPServer_p_WSConnectionTimeout) 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](#bytes_sent-property) property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the [on_ready_to_send](#on_ready_to_send-event) event before attempting to send data again.

NOTE: The [on_ready_to_send](#on_ready_to_send-event) event is not fired when part of the data is sent successfully.

# shutdown method

This method shuts down the server.

## Syntax

```text
def shutdown() -> None: ...
```

## Remarks

This method shuts down the server. Calling this method is equivalent to calling [stop_listening](#stop_listening-method) and then breaking every client connection by calling [disconnect](#disconnect-method).

# start_listening method

This method starts listening for incoming connections.

## Syntax

```text
def start_listening() -> None: ...
```

## Remarks

This method begins listening for incoming connections on the port specified by [local_port](#local_port-property). Once listening, events will fire as new clients connect and data are transferred.

To stop listening for new connections, call [stop_listening](#stop_listening-method). To stop listening for new connections and to disconnect all existing clients, call [shutdown](#shutdown-method).

# start_ssl method

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

## Syntax

```text
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](#ssl_start_mode-property) property for more information.

NOTE: The [on_connected](#on_connected-event) event will fire again after the SSL negotiation is complete.

# stop_listening method

This method stops listening for new connections.

## Syntax

```text
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](#shutdown-method) instead.

# on_connected event

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

## Syntax

```text
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, *status_code* is 0, and *description* is "OK".

If the connection fails, *status_code* has the error code returned by the system. *description* contains a description of this code. The value of *status_code* is equal to the value of the system error.

Please refer to the [Error Codes](#tcpserver-errors) section for more information.

# on_connection_request event

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

## Syntax

```text
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

```text
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 *connection_id*. The incoming data are provided through the *text* parameter.

*eol* indicates whether or not the [eol](#eol-property) string was found at the end of *text*. If the [eol](#eol-property) string was found, then *eol* is True.

If Text is part of the data portion of length larger than either [default_max_line_length](#default_max_line_length-property) or  with no [eol](#eol-property) 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](#eol-property) 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

```text
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, *status_code* is 0, and *description* is "OK".

If the connection is broken for any other reason, *status_code* has the error code returned by the system. *description* contains a description of this code. The value of *status_code* is equal to the value of the system error.

Please refer to the [Error Codes](#tcpserver-errors) section for more information.

# on_error event

This event fires information about errors during data delivery.

## Syntax

```text
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.

*error_code* 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](#tcpserver-errors) section.

*connection_id* 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

```text
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 [send](#send-method). 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

```text
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

```text
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](#ssl_provider-property) 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](#ssl_provider-property) 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.

*connection_id* is the connection Id of the client requesting the connection.

*supported_cipher_suites* is a comma-separated list of cipher suites that the client supports.

*supported_signature_algs* is a comma-separated list of certificate signature algorithms that the client supports.

*cert_store_type* 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:

```csharp
sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11,
                               @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll",
                               "123456", // PIN
                               "CN=cert_subject");
sftp.SSHUser = "test";
sftp.SSHLogon("myhost", 22);
```

```csharp
certmgr.CertStoreType = CertStoreTypes.cstPKCS11;
certmgr.OnCertList += (s, e) => {
  secKeyBlob = e.CertEncoded;
};
certmgr.CertStore = @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll";
certmgr.CertStorePassword = "123456"; // PIN
certmgr.ListStoreCertificates();

sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11, secKeyBlob, "123456", "*");
sftp.SSHUser = "test";
sftp.SSHLogon("myhost", 22);
```

|  |  |
| --- | --- |
| 0 (cstUser - default) | For Windows, this specifies that the certificate store is a certificate store owned by the current user. NOTE: This store type is not available in Java. |
| 1 (cstMachine) | For Windows, this specifies that the certificate store is a machine store. NOTE: This store type is not available in Java. |
| 2 (cstPFXFile) | The certificate store is the name of a PFX (PKCS#12) file containing certificates. |
| 3 (cstPFXBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in PFX (PKCS#12) format. |
| 4 (cstJKSFile) | The certificate store is the name of a Java Key Store (JKS) file containing certificates. NOTE: This store type is only available in Java. |
| 5 (cstJKSBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in Java Key Store (JKS) format. NOTE: This store type is only available in Java. |
| 6 (cstPEMKeyFile) | The certificate store is the name of a PEM-encoded file that contains a private key and an optional certificate. |
| 7 (cstPEMKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains a private key and an optional certificate. |
| 8 (cstPublicKeyFile) | The certificate store is the name of a file that contains a PEM- or DER-encoded public key certificate. |
| 9 (cstPublicKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains a PEM- or DER-encoded public key certificate. |
| 10 (cstSSHPublicKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains an SSH-style public key. |
| 11 (cstP7BFile) | The certificate store is the name of a PKCS#7 file containing certificates. |
| 12 (cstP7BBlob) | The certificate store is a string (binary) representing a certificate store in PKCS#7 format. |
| 13 (cstSSHPublicKeyFile) | The certificate store is the name of a file that contains an SSH-style public key. |
| 14 (cstPPKFile) | The certificate store is the name of a file that contains a PPK (PuTTY Private Key). |
| 15 (cstPPKBlob) | The certificate store is a string (binary) that contains a PPK (PuTTY Private Key). |
| 16 (cstXMLFile) | The certificate store is the name of a file that contains a certificate in XML format. |
| 17 (cstXMLBlob) | The certificate store is a string that contains a certificate in XML format. |
| 18 (cstJWKFile) | The certificate store is the name of a file that contains a JWK (JSON Web Key). |
| 19 (cstJWKBlob) | The certificate store is a string that contains a JWK (JSON Web Key). |
| 21 (cstBCFKSFile) | The certificate store is the name of a file that contains a BCFKS (Bouncy Castle FIPS Key Store). NOTE: This store type is only available in Java and .NET. |
| 22 (cstBCFKSBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in BCFKS (Bouncy Castle FIPS Key Store) format. NOTE: This store type is only available in Java and .NET. |
| 23 (cstPKCS11) | The certificate is present on a physical security key accessible via a PKCS#11 interface. To use a security key, create a new Certificate object and pass cstPKCS11 as the [](#f_StoreType), the full path of the PKCS#11 DLL as the [](#f_Store), and the PIN as the [](#f_StorePassword). Code Example. SSH Authentication with Security Key (without CertMgr): Alternatively, collect the necessary data using the [CertMgr](CertMgr.md#CertMgr) class by calling the [list_store_certificates](CertMgr.md#CertMgr_m_ListStoreCertificates) method after setting the corresponding properties accordingly. The certificate information returned in the [on_cert_list](CertMgr.md#CertMgr_e_CertList) event's CertEncoded parameter may be saved for later use. When using a certificate obtained with this approach, pass the previously saved security key information as the [](#f_Store) and set [](#f_StorePassword) to the PIN. Code Example. SSH Authentication with Security Key (with CertMgr): |
| 99 (cstAuto) | The store type is automatically detected from the input data. This setting may be used with both public and private keys and can detect any of the supported formats automatically. |

*cert_store* is the store name or location of the alternate certificate to use for this connection.

 Designations of certificate stores are platform dependent.

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

|  |  |
| --- | --- |
| MY | A certificate store holding personal certificates with their associated private keys. |
| CA | Certifying authority certificates. |
| ROOT | Root certificates. |

When the certificate store type is *cstPFXFile*, this property must be set to the name of the file. When the type is *cstPFXBlob*, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store).

*cert_password* is the password of the certificate store containing the alternate certificate to use for this connection.

*cert_subject* is the subject of the alternate certificate to use for this connection.

The special value *** matches any subject and will select the first certificate in the store. The certificate subject is a comma-separated list of distinguished name fields and values. For instance, "CN=www.server.com, OU=test, C=US, E=example@email.com". Common fields and their meanings are as follows:

| Field | Meaning |
| --- | --- |
| CN | Common Name. This is commonly a hostname like www.server.com. |
| O | Organization |
| OU | Organizational Unit |
| L | Locality |
| S | State |
| C | Country |
| E | Email Address |

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

# on_ssl_status event

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

## Syntax

```text
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](#config-method) 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](#on_connection_request-event) event fires with an *Accept* value set to *False*. If no action is taken within the [on_connection_request](#on_connection_request-event) 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](#on_connection_request-event) event fires with an *Accept* value set to *False*. If no action is taken within the [on_connection_request](#on_connection_request-event) 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](#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](#InBufferSize) reverts to its defined size. The same thing will happen if you attempt to make it too large or too small.

[InBufferSize](#InBufferSize) is shared among incoming connections. When the setting is set, the corresponding value is set for incoming connections as they are accepted. Existing connections are not modified.

**KeepAliveInterval**: The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.A TCP keep-alive packet will be sent after a period of inactivity, as defined by [KeepAliveTime](#KeepAliveTime). If no acknowledgment is received from the remote host, the keep-alive packet will be sent again. This setting specifies the interval at which the successive keep-alive packets are sent in milliseconds. If this value is not specified here, the system default is 1 second. This setting is applicable to all connections.

NOTE: This value is not applicable in macOS.

**KeepAliveRetryCount**: The number of keep-alive packets to be sent before the remotehost is considered disconnected.A TCP keep-alive packet will be sent after a period of inactivity, as defined by [KeepAliveTime](#KeepAliveTime). If no acknowledgment is received from the remote host, the keep-alive packet will be sent again. This setting specifies the 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 setting must be set before [listening](#listening-property) 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](#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](#OutBufferSize) reverts to its defined size. The same thing will happen if you attempt to make it too large or too small.

[OutBufferSize](#OutBufferSize) is shared among incoming connections. When the setting is set, the corresponding value is set for incoming connections as they are accepted. Existing connections are not modified.

**TcpNoDelay**: Whether or not to delay when sending packets. When set to True, the socket will send all data that are ready to send at once. When set to False, the socket will send smaller buffered packets of data at small intervals. This is known as the Nagle algorithm.

By default, this configuration setting is set to False.

**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 setting must be set before [listening](#listening-property) 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](#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 setting must be set before [listening](#listening-property) 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](#ssl_provider-property) is set to *Internal*, this configuration setting controls whether Secure Sockets Layer (SSL) packets should be logged. By default, this configuration setting is *False*, as it is useful only for debugging purposes.

When enabled, SSL packet logs are output using the [on_ssl_status](#on_ssl_status-event) event, which will fire each time an SSL packet is sent or received.

Enabling this configuration setting has no effect if [ssl_provider](#ssl_provider-property) is set to *Platform*.

**OpenSSLCADir**: The path to a directory containing CA certificates.This functionality is available only when the provider is OpenSSL.

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

**OpenSSLCAFile**: Name of the file containing the list of CA's trusted by your application.This functionality is available only when the provider is OpenSSL.

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

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

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

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

 Before, between, and after the certificate text is allowed, which can be used, for example, for descriptions of the certificates. Refer to the OpenSSL man page SSL_CTX_load_verify_locations(3) for details.

**OpenSSLCipherList**: A string that controls the ciphers to be used by SSL.This functionality is available only when the provider is OpenSSL.

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

**OpenSSLPrngSeedData**: The data to seed the pseudo random number generator (PRNG).This functionality is available only when the provider is OpenSSL.

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

**ReuseSSLSession**: Determines if the SSL session is reused.

If set to True, the 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 configuration 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 as follows:

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

**SSLCACerts**: A newline separated list of CA certificates to be included when performing an SSL handshake.When [ssl_provider](#ssl_provider-property) is set to *Internal*, this configuration setting specifies one or more CA certificates to be included with the ssl_cert property. Some servers or clients require the entire chain, including CA certificates, to be presented when performing SSL authentication. The value of this configuration setting is a newline-separated (CR/LF) list of certificates. For instance:

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

**SSLCheckCRL**: Whether to check the Certificate Revocation List for the server certificate.This configuration setting specifies whether the class will check the Certificate Revocation List (CRL) 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 it will continue without an error if the server's certificate does not support CRL. When set to 2, it will perform the CRL check and will throw an error if CRL is not supported.

This configuration setting is supported only in the Java, C#, and C++ editions. In the C++ edition, it is supported only on Windows operating systems.

**SSLCheckOCSP**: Whether to use OCSP to check the status of the server certificate.This configuration setting specifies whether the class will use OCSP to check the validity of the server certificate. If set to 1 or 2, the class will first obtain the Online Certificate Status Protocol (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 it will continue without an error if the server's certificate does not support OCSP. When set to 2, it will perform the OCSP check and will throw an error if OCSP is not supported.

This configuration setting is supported only in the Java, C#, and C++ editions. In the C++ edition, it is supported only on Windows operating systems.

**SSLCipherStrength**: The minimum cipher strength used for bulk encryption. This minimum cipher strength is largely dependent on the security modules installed on the system. If the cipher strength specified is not supported, an error will be returned when connections are initiated.

NOTE: This configuration setting contains the minimum cipher strength requested from the security library. The actual cipher strength used for the connection is shown by the [on_ssl_status](#on_ssl_status-event) event.

Use this configuration setting with caution. Requesting a lower cipher strength than necessary could potentially cause serious security vulnerabilities in your application.

When the provider is OpenSSL, [SSLCipherStrength](#SSLCipherStrength) is currently not supported. This functionality is instead made available through the [OpenSSLCipherList](#OpenSSLCipherList) configuration setting.

**SSLClientCACerts**: A newline separated list of CA certificates to use during SSL client certificate validation.This configuration setting is only applicable to server components (e.g., TCPServer) see [SSLServerCACerts](#SSLServerCACerts) for client components (e.g., TCPClient). This setting can be used to optionally specify one or more CA certificates to be used when verifying the client certificate that is presented by the client during the SSL handshake when [ssl_authenticate_clients](#ssl_authenticate_clients-property) is enabled. When verifying the client's certificate, the certificates trusted by the system will be used as part of the verification process. If the client's CA certificates are not installed to the trusted system store, they may be specified here so they are included when performing the verification process. This configuration setting should be set only if the client's CA certificates are not already trusted on the system and cannot be installed to the trusted system store.

The value of this configuration setting is a newline-separated (CR/LF) list of certificates. For instance:

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

**SSLEnabledCipherSuites**: The cipher suite to be used in an SSL negotiation.This configuration setting enables the cipher suites to be used in SSL negotiation.

By default, the enabled cipher suites will include all available ciphers ("*").

The special value "*" means that the class will pick all of the supported cipher suites. If [SSLEnabledCipherSuites](#SSLEnabledCipherSuites) is set to any other value, only the specified cipher suites will be considered.

Multiple cipher suites are separated by semicolons.

Example values when [ssl_provider](#ssl_provider-property) is set to *Platform* include the following:

```text
obj.config("SSLEnabledCipherSuites=*");
obj.config("SSLEnabledCipherSuites=CALG_AES_256");
obj.config("SSLEnabledCipherSuites=CALG_AES_256;CALG_3DES");
```

 Possible values when [ssl_provider](#ssl_provider-property) is set to *Platform* include the following:

- CALG_3DES
- CALG_3DES_112
- CALG_AES
- CALG_AES_128
- CALG_AES_192
- CALG_AES_256
- CALG_AGREEDKEY_ANY
- CALG_CYLINK_MEK
- CALG_DES
- CALG_DESX
- CALG_DH_EPHEM
- CALG_DH_SF
- CALG_DSS_SIGN
- CALG_ECDH
- CALG_ECDH_EPHEM
- CALG_ECDSA
- CALG_ECMQV
- CALG_HASH_REPLACE_OWF
- CALG_HUGHES_MD5
- CALG_HMAC
- CALG_KEA_KEYX
- CALG_MAC
- CALG_MD2
- CALG_MD4
- CALG_MD5
- CALG_NO_SIGN
- CALG_OID_INFO_CNG_ONLY
- CALG_OID_INFO_PARAMETERS
- CALG_PCT1_MASTER
- CALG_RC2
- CALG_RC4
- CALG_RC5
- CALG_RSA_KEYX
- CALG_RSA_SIGN
- CALG_SCHANNEL_ENC_KEY
- CALG_SCHANNEL_MAC_KEY
- CALG_SCHANNEL_MASTER_HASH
- CALG_SEAL
- CALG_SHA
- CALG_SHA1
- CALG_SHA_256
- CALG_SHA_384
- CALG_SHA_512
- CALG_SKIPJACK
- CALG_SSL2_MASTER
- CALG_SSL3_MASTER
- CALG_SSL3_SHAMD5
- CALG_TEK
- CALG_TLS1_MASTER
- CALG_TLS1PRF

 Example values when [ssl_provider](#ssl_provider-property) is set to *Internal*include the following:

```text
obj.config("SSLEnabledCipherSuites=*");
obj.config("SSLEnabledCipherSuites=TLS_DHE_DSS_WITH_AES_128_CBC_SHA");
obj.config("SSLEnabledCipherSuites=TLS_DHE_DSS_WITH_AES_128_CBC_SHA;TLS_ECDH_RSA_WITH_AES_128_CBC_SHA");
```

 Possible values when [ssl_provider](#ssl_provider-property) is set to *Internal* include the following:

- TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
- TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
- TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
- TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
- TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384
- TLS_RSA_WITH_AES_256_GCM_SHA384
- TLS_RSA_WITH_AES_128_GCM_SHA256
- TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256
- TLS_DHE_DSS_WITH_AES_256_GCM_SHA384
- TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
- TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384
- TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256
- TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
- TLS_DHE_DSS_WITH_AES_128_GCM_SHA256
- TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
- TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
- TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384
- TLS_DHE_DSS_WITH_AES_256_CBC_SHA256
- TLS_RSA_WITH_AES_256_CBC_SHA256
- TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
- TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384
- TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
- TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
- TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
- TLS_RSA_WITH_AES_128_CBC_SHA256
- TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256
- TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256
- TLS_DHE_DSS_WITH_AES_128_CBC_SHA256
- TLS_RSA_WITH_AES_256_CBC_SHA
- TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
- TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
- TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA
- TLS_DHE_RSA_WITH_AES_256_CBC_SHA
- TLS_ECDH_RSA_WITH_AES_256_CBC_SHA
- TLS_DHE_DSS_WITH_AES_256_CBC_SHA
- TLS_RSA_WITH_AES_128_CBC_SHA
- TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
- TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
- TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA
- TLS_ECDH_RSA_WITH_AES_128_CBC_SHA
- TLS_DHE_RSA_WITH_AES_128_CBC_SHA
- TLS_DHE_DSS_WITH_AES_128_CBC_SHA
- TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA
- TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA
- TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA
- TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA
- TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA
- TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA
- TLS_RSA_WITH_3DES_EDE_CBC_SHA
- TLS_RSA_WITH_DES_CBC_SHA
- TLS_DHE_RSA_WITH_DES_CBC_SHA
- TLS_DHE_DSS_WITH_DES_CBC_SHA
- TLS_RSA_WITH_RC4_128_MD5
- TLS_RSA_WITH_RC4_128_SHA

When TLS 1.3 is negotiated (see [SSLEnabledProtocols](#SSLEnabledProtocols)), only the following cipher suites are supported:

- TLS_AES_256_GCM_SHA384
- TLS_CHACHA20_POLY1305_SHA256
- TLS_AES_128_GCM_SHA256

[SSLEnabledCipherSuites](#SSLEnabledCipherSuites) is used together with [SSLCipherStrength](#SSLCipherStrength).

**SSLEnabledProtocols**: Used to enable/disable the supported security protocols.This configuration setting is used to enable or disable the supported security protocols.

Not all supported protocols are enabled by default. The default value is *4032* for client components, and *3072* for server components. To specify a combination of enabled protocol versions set this config to the binary *OR* of one or more of the following values:

|  |  |
| --- | --- |
| TLS1.3 | 12288 (Hex 3000) |
| TLS1.2 | 3072 (Hex C00) (Default - Client and Server) |
| TLS1.1 | 768 (Hex 300) (Default - Client) |
| TLS1 | 192 (Hex C0) (Default - Client) |
| SSL3 | 48 (Hex 30) |
| SSL2 | 12 (Hex 0C) |

Note that only TLS 1.2 is enabled for server components that accept incoming connections. This adheres to industry standards to ensure a secure connection. Client components enable TLS 1.0, TLS 1.1, and TLS 1.2 by default and will negotiate the highest mutually supported version when connecting to a server, which should be TLS 1.2 in most cases.

**SSLEnabledProtocols: Transport Layer Security (TLS) 1.3 Notes:**

By default when TLS 1.3 is enabled, the class will first try to use the platform TLS 1.3 implementation when the [ssl_provider](#ssl_provider-property) is set to Automatic for all editions. If the platform TLS 1.3 implementation is not available, the internal implementation will be used.

In editions that are designed to run on Windows, [ssl_provider](#ssl_provider-property) can be set to Platform to use the platform implementation instead of the internal implementation. When configured in this manner, please note that the platform provider is supported only on Windows 11/Windows Server 2022 and up. The default internal provider is available on all platforms and is not restricted to any specific OS version.

If set to *1* (Platform provider), please be aware of the following notes:

- The platform provider is available only on Windows 11/Windows Server 2022 and up.
- [SSLEnabledCipherSuites](#SSLEnabledCipherSuites) and other similar SSL configuration settings are not supported.
- If [SSLEnabledProtocols](#SSLEnabledProtocols) includes both TLS 1.3 and TLS 1.2, these restrictions are still applicable even if TLS 1.2 is negotiated. Enabling TLS 1.3 with the platform provider changes the implementation used for all TLS versions.

**SSLEnabledProtocols: SSL2 and SSL3 Notes: **

SSL 2.0 and 3.0 are not supported by the class when the [ssl_provider](#ssl_provider-property) is set to internal. To use SSL 2.0 or SSL 3.0, the platform security API must have the protocols enabled and [ssl_provider](#ssl_provider-property) needs to be set to platform.

**SSLEnableRenegotiation**: Whether the renegotiation_info SSL extension is supported.This configuration setting specifies whether the renegotiation_info SSL extension will be used in the request when using the internal security API. This configuration setting is *False* by default, but it can be set to *True* to enable the extension.

This configuration setting is applicable only when [ssl_provider](#ssl_provider-property) is set to *Internal*.

**SSLIncludeCertChain**: Whether the entire certificate chain is included in the SSLServerAuthentication event.This configuration setting specifies whether the Encoded parameter of the 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 configuration 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 traffic for debugging purposes. When writing to this file, the class will only append, it will not overwrite previous values.

NOTE: This configuration setting is applicable only when [ssl_provider](#ssl_provider-property) is set to *Internal*.

**SSLNegotiatedCipher**: Returns the negotiated cipher suite.This configuration setting returns the cipher suite negotiated during the SSL handshake.

NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example:

```csharp
server.Config("SSLNegotiatedCipher[connId]");
```

**SSLNegotiatedCipherStrength**: Returns the negotiated cipher suite strength.This configuration setting returns the strength of the cipher suite negotiated during the SSL handshake.

NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example:

```csharp
server.Config("SSLNegotiatedCipherStrength[connId]");
```

**SSLNegotiatedCipherSuite**: Returns the negotiated cipher suite.This configuration setting returns the cipher suite negotiated during the SSL handshake represented as a single string.

NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example:

```csharp
server.Config("SSLNegotiatedCipherSuite[connId]");
```

**SSLNegotiatedKeyExchange**: Returns the negotiated key exchange algorithm.This configuration setting returns the key exchange algorithm negotiated during the SSL handshake.

NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example:

```csharp
server.Config("SSLNegotiatedKeyExchange[connId]");
```

**SSLNegotiatedKeyExchangeStrength**: Returns the negotiated key exchange algorithm strength.This configuration setting returns the strength of the key exchange algorithm negotiated during the SSL handshake.

NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example:

```csharp
server.Config("SSLNegotiatedKeyExchangeStrength[connId]");
```

**SSLNegotiatedVersion**: Returns the negotiated protocol version.This configuration setting returns the protocol version negotiated during the SSL handshake.

NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example:

```csharp
server.Config("SSLNegotiatedVersion[connId]");
```

**SSLSecurityFlags**: Flags that control certificate verification.The following flags are defined (specified in hexadecimal notation). They can be ORed together to exclude multiple conditions:

|  |  |
| --- | --- |
| 0x00000001 | Ignore time validity status of certificate. |
| 0x00000002 | Ignore time validity status of CTL. |
| 0x00000004 | Ignore non-nested certificate times. |
| 0x00000010 | Allow unknown certificate authority. |
| 0x00000020 | Ignore wrong certificate usage. |
| 0x00000100 | Ignore unknown certificate revocation status. |
| 0x00000200 | Ignore unknown CTL signer revocation status. |
| 0x00000400 | Ignore unknown certificate authority revocation status. |
| 0x00000800 | Ignore unknown root revocation status. |
| 0x00008000 | Allow test root certificate. |
| 0x00004000 | Trust test root certificate. |
| 0x80000000 | Ignore non-matching CN (certificate CN non-matching server name). |

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

**SSLServerCACerts**: A newline separated list of CA certificates to use during SSL server certificate validation.This configuration setting is only used by client components (e.g., TCPClient) see [SSLClientCACerts](#SSLClientCACerts) for server components (e.g., TCPServer). This configuration setting can be used to optionally specify one or more CA certificates to be used when connecting to the server and verifying the server certificate. When verifying the server's certificate, the certificates trusted by the system will be used as part of the verification process. If the server's CA certificates are not installed to the trusted system store, they may be specified here so they are included when performing the verification process. This configuration setting should be set only if the server's CA certificates are not already trusted on the system and cannot be installed to the trusted system store.

The value of this configuration setting is a newline-separated (CR/LF) list of certificates. For instance:

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

**TLS12SignatureAlgorithms**: Defines the allowed TLS 1.2 signature algorithms when SSLProvider is set to Internal.This configuration setting specifies the allowed server certificate signature algorithms when [ssl_provider](#ssl_provider-property) is set to *Internal* and [SSLEnabledProtocols](#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 configuration 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:

```csharp
component.SSLProvider = TCPClientSSLProviders.sslpInternal;
component.Config("SSLEnabledProtocols=3072"); //TLS 1.2
component.Config("TLS12SignatureAlgorithms=sha256-rsa,sha256-dsa,sha1-rsa,sha1-dsa");
```

 The default value for this configuration setting is *sha512-ecdsa,sha512-rsa,sha512-dsa,sha384-ecdsa,sha384-rsa,sha384-dsa,sha256-ecdsa,sha256-rsa,sha256-dsa,sha224-ecdsa,sha224-rsa,sha224-dsa,sha1-ecdsa,sha1-rsa,sha1-dsa*.

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

**TLS12SupportedGroups**: The supported groups for ECC.This configuration setting specifies a comma-separated list of named groups used in TLS 1.2 for ECC.

The default value is *ecdhe_secp256r1,ecdhe_secp384r1,ecdhe_secp521r1*.

When using TLS 1.2 and [ssl_provider](#ssl_provider-property) is set to *Internal*, the values refer to the supported groups for ECC. The following values are supported:

- "ecdhe_secp256r1" (default)
- "ecdhe_secp384r1" (default)
- "ecdhe_secp521r1" (default)

**TLS13KeyShareGroups**: The groups for which to pregenerate key shares.This configuration setting specifies a comma-separated list of named groups used in TLS 1.3 for key exchange. The groups specified here will have key share data pregenerated locally before establishing a connection. This can prevent an additional roundtrip during the handshake if the group is supported by the server.

The default value is set to balance common supported groups and the computational resources required to generate key shares. As a result, only some groups are included by default in this configuration setting.

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

In most cases, this configuration setting does not need to be modified. This should be modified only if there is a specific reason to do so.

The default value is *ecdhe_x25519,ecdhe_secp256r1,ecdhe_secp384r1,ffdhe_2048,ffdhe_3072*

The values are ordered from most preferred to least preferred. The following values are supported:

- "ecdhe_x25519" (default)
- "ecdhe_x448"
- "ecdhe_secp256r1" (default)
- "ecdhe_secp384r1" (default)
- "ecdhe_secp521r1"
- "ffdhe_2048" (default)
- "ffdhe_3072" (default)
- "ffdhe_4096"
- "ffdhe_6144"
- "ffdhe_8192"

**TLS13SignatureAlgorithms**: The allowed certificate signature algorithms.This configuration setting holds a comma-separated list of allowed signature algorithms. Possible values include the following:

- "ed25519" (default)
- "ed448" (default)
- "ecdsa_secp256r1_sha256" (default)
- "ecdsa_secp384r1_sha384" (default)
- "ecdsa_secp521r1_sha512" (default)
- "rsa_pkcs1_sha256" (default)
- "rsa_pkcs1_sha384" (default)
- "rsa_pkcs1_sha512" (default)
- "rsa_pss_sha256" (default)
- "rsa_pss_sha384" (default)
- "rsa_pss_sha512" (default)

 The default value is *rsa_pss_sha256,rsa_pss_sha384,rsa_pss_sha512,rsa_pkcs1_sha256,rsa_pkcs1_sha384,rsa_pkcs1_sha512,ecdsa_secp256r1_sha256,ecdsa_secp384r1_sha384,ecdsa_secp521r1_sha512,ed25519,ed448*. This configuration setting is applicable only when [SSLEnabledProtocols](#SSLEnabledProtocols) includes TLS 1.3.

**TLS13SupportedGroups**: The supported groups for (EC)DHE key exchange.This configuration setting specifies a comma-separated list of named groups used in TLS 1.3 for key exchange. This configuration setting should be modified only if there is a specific reason to do so.

The default value is *ecdhe_x25519,ecdhe_x448,ecdhe_secp256r1,ecdhe_secp384r1,ecdhe_secp521r1,ffdhe_2048,ffdhe_3072,ffdhe_4096,ffdhe_6144,ffdhe_8192,mlkem_512,mlkem_768,mlkem_1024,x25519_mlkem_768,secp256r1_mlkem_768*

The values are ordered from most preferred to least preferred. The following values are supported:

- "ecdhe_x25519" (default)
- "ecdhe_x448" (default)
- "ecdhe_secp256r1" (default)
- "ecdhe_secp384r1" (default)
- "ecdhe_secp521r1" (default)
- "ffdhe_2048" (default)
- "ffdhe_3072" (default)
- "ffdhe_4096" (default)
- "ffdhe_6144" (default)
- "ffdhe_8192" (default)
- "mlkem_512" (default)
- "mlkem_768" (default)
- "mlkem_1024" (default)
- "x25519_mlkem_768" (default)
- "secp256r1_mlkem_768" (default)

Post-quantum algorithms (*mlkem_512,mlkem_768,mlkem_1024,x25519_mlkem_768,secp256r1_mlkem_768*) in our components rely on the operating system's underlying cryptographic primitives. The following platforms are currently supported:

-  Windows Server 2025
-  Windows 11 24H2
-  Windows 11 25H2

### Base Config Settings

**BuildInfo**: Information about the product's build.When queried, this setting will return a string containing information about the product's build.

**CodePage**: The system code page used for Unicode to Multibyte translations.The default code page is Unicode UTF-8 (65001).

The following is a list of valid code page identifiers:

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

 The following is a list of valid code page identifiers for Mac OS only:

|  |  |
| --- | --- |
| Identifier | Name |
| 1 | ASCII |
| 2 | NEXTSTEP |
| 3 | JapaneseEUC |
| 4 | UTF8 |
| 5 | ISOLatin1 |
| 6 | Symbol |
| 7 | NonLossyASCII |
| 8 | ShiftJIS |
| 9 | ISOLatin2 |
| 10 | Unicode |
| 11 | WindowsCP1251 |
| 12 | WindowsCP1252 |
| 13 | WindowsCP1253 |
| 14 | WindowsCP1254 |
| 15 | WindowsCP1250 |
| 21 | ISO2022JP |
| 30 | MacOSRoman |
| 10 | UTF16String |
| 0x90000100 | UTF16BigEndian |
| 0x94000100 | UTF16LittleEndian |
| 0x8c000100 | UTF32String |
| 0x98000100 | UTF32BigEndian |
| 0x9c000100 | UTF32LittleEndian |
| 65536 | Proprietary |

**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.

**MaskSensitiveData**: Whether sensitive data is masked in log messages.In certain circumstances it may be beneficial to mask sensitive data, like passwords, in log messages. Set this to *True* to mask sensitive data. The default is *True*.

**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](#do_events-method) is called, the class will wait for the amount of time specified here before returning. The default value is 20.

**UseInternalSecurityAPI**: 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 configuration 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](platforms.md) section.

# TCPServer Errors

### TCPServer Errors

|  |  |
| --- | --- |
| 100 | You cannot change the [remote_port](#remote_port-property) at this time. A connection is in progress. |
| 101 | You cannot change the [remote_host](#remote_host-property) at this time. A connection is in progress. |
| 102 | The [remote_host](#remote_host-property) address is invalid (0.0.0.0). |
| 104 | TCPServer is already listening. |
| 106 | Cannot change [local_port](#local_port-property) when TCPServer is listening. |
| 107 | Cannot change [local_host](#local_host-property) when TCPServer is listening. |
| 108 | Cannot change [MaxConnections](#MaxConnections) when TCPServer is listening. |
| 112 | You cannot change [MaxLineLength](#MaxLineLength) at this time. A connection is in progress. |
| 116 | [remote_port](#remote_port-property) cannot be zero. Please specify a valid service port number. |
| 126 | Invalid ConnectionId. |
| 135 | Operation would block. |

### SSL Errors

|  |  |
| --- | --- |
| 270 | Cannot load specified security library. |
| 271 | Cannot open certificate store. |
| 272 | Cannot find specified certificate. |
| 273 | Cannot acquire security credentials. |
| 274 | Cannot find certificate chain. |
| 275 | Cannot verify certificate chain. |
| 276 | Error during handshake. |
| 280 | Error verifying certificate. |
| 281 | Could not find client certificate. |
| 282 | Could not find server certificate. |
| 283 | Error encrypting data. |
| 284 | Error decrypting data. |

### TCP/IP Errors

|  |  |
| --- | --- |
| 10004 | [10004] Interrupted system call. |
| 10009 | [10009] Bad file number. |
| 10013 | [10013] Access denied. |
| 10014 | [10014] Bad address. |
| 10022 | [10022] Invalid argument. |
| 10024 | [10024] Too many open files. |
| 10035 | [10035] Operation would block. |
| 10036 | [10036] Operation now in progress. |
| 10037 | [10037] Operation already in progress. |
| 10038 | [10038] Socket operation on nonsocket. |
| 10039 | [10039] Destination address required. |
| 10040 | [10040] Message is too long. |
| 10041 | [10041] Protocol wrong type for socket. |
| 10042 | [10042] Bad protocol option. |
| 10043 | [10043] Protocol is not supported. |
| 10044 | [10044] Socket type is not supported. |
| 10045 | [10045] Operation is not supported on socket. |
| 10046 | [10046] Protocol family is not supported. |
| 10047 | [10047] Address family is not supported by protocol family. |
| 10048 | [10048] Address already in use. |
| 10049 | [10049] Cannot assign requested address. |
| 10050 | [10050] Network is down. |
| 10051 | [10051] Network is unreachable. |
| 10052 | [10052] Net dropped connection or reset. |
| 10053 | [10053] Software caused connection abort. |
| 10054 | [10054] Connection reset by peer. |
| 10055 | [10055] No buffer space available. |
| 10056 | [10056] Socket is already connected. |
| 10057 | [10057] Socket is not connected. |
| 10058 | [10058] Cannot send after socket shutdown. |
| 10059 | [10059] Too many references, cannot splice. |
| 10060 | [10060] Connection timed out. |
| 10061 | [10061] Connection refused. |
| 10062 | [10062] Too many levels of symbolic links. |
| 10063 | [10063] File name is too long. |
| 10064 | [10064] Host is down. |
| 10065 | [10065] No route to host. |
| 10066 | [10066] Directory is not empty |
| 10067 | [10067] Too many processes. |
| 10068 | [10068] Too many users. |
| 10069 | [10069] Disc Quota Exceeded. |
| 10070 | [10070] Stale NFS file handle. |
| 10071 | [10071] Too many levels of remote in path. |
| 10091 | [10091] Network subsystem is unavailable. |
| 10092 | [10092] WINSOCK DLL Version out of range. |
| 10093 | [10093] Winsock is not loaded yet. |
| 11001 | [11001] Host not found. |
| 11002 | [11002] Nonauthoritative 'Host not found' (try again or check DNS setup). |
| 11003 | [11003] Nonrecoverable errors: FORMERR, REFUSED, NOTIMP. |
| 11004 | [11004] Valid name, no data record (check DNS setup). |
