SSHServer Class

Properties   Methods   Events   Config Settings   Errors  

The SSHServer class is used to create Secure Shell (SSH) servers. The class handles multiple simultaneous connections on the same TCP/IP port (service port). It is designed to balance the load between connections for a fast, powerful server.

Syntax

class ipworksssh.SSHServer

Remarks

The SSHServer class is the SSH-enabled equivalent of the IPWorks TCPServer class, extended by a set of new properties and events that deal with SSH security. The ssh_compression_algorithms and ssh_encryption_algorithms properties determine which protocols are enabled for the SSH handshake. The ssh_cert* properties are used to select a certificate for the server (please note that a valid certificate MUST be selected before the server can function). The on_ssh_user_auth_request event will allow you to use authenticate clients using digital certificates or passwords. Finally, the on_ssh_status event provides information about the SSH handshake and underlying protocol notifications.

By default, each instance of SSHServer can handle up to 1000 simultaneous incoming connections (this number may be increased up to 100,000, or decreased to a lower value by using the MaxConnections configuration setting).

SSH connections are identified by a ConnectionId. Events relating to these connections as a whole will use the ConnectionId to identify the specific connection. Connections may also contained one or more multiplexed channels, which are identified by a ChannelId. Channel-level events will specify the ChannelId to which they relate.

SSHServer can start to listen on a port by setting the listening property to True. When a remote host asks for a connection, the on_connection_request event is fired. At that point, the connection can either be accepted or rejected. If the connection is accepted, a ConnectionId is assigned, and communication can start. From this point on, the operation is very similar to SSHClient. Data can be sent to an individual SSHChannel using send_channel_data. The address and port of the incoming connection can be found by querying the client_remote_host and client_remote_port properties.

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

Property List


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

ssh_channel_countThe number of records in the arrays.
bytes_sentThe number of bytes actually sent after a sending channel data.
channel_idAn id generated by the class to identify the current SSH channel.
data_to_sendA string of data to be sent to the remote host.
ready_to_sendThis property is True when data can be sent over the SSH Channel.
record_lengthThe length of received data records.
serviceThis property holds the channel type that was requested when opening the channel.
connection_backlogThis property includes the maximum number of pending connections maintained by the Transmission Control Protocol (TCP)/IP subsystem.
ssh_connection_countThe number of records in the SSHConnection arrays.
ssh_connection_connectedUsed to disconnect individual connections and/or show their status.
ssh_connection_local_addressThis property shows the IP address of the interface through which the connection is passing.
ssh_connection_remote_hostThe RemoteHost shows the IP address of the remote host through which the connection is coming.
ssh_connection_remote_portThe RemotePort shows the TCP port on the remote host through which the connection is coming.
ssh_connection_timeoutA timeout for the class.
default_auth_methodsSpecifies the supported authentication methods.
default_idle_timeoutThis property includes the default idle timeout for inactive clients.
default_timeoutAn initial timeout value to be used by incoming connections.
keyboard_interactive_messageThe instructions to send to the client during keyboard-interactive authentication.
keyboard_interactive_prompt_countThe number of records in the KeyboardInteractivePrompt arrays.
keyboard_interactive_prompt_echoSpecifies if the client should echo the value entered by the user or not.
keyboard_interactive_prompt_promptThe prompt label/text the client should present to the user.
listeningIf set to True, the class accepts incoming connections on LocalPort.
local_hostThe name of the local host or user-assigned IP interface through which connections are initiated or accepted.
local_portThe TCP port in the local host where the class listens.
ssh_cert_encodedThis is the certificate (PEM/Base64 encoded).
ssh_cert_storeThis is the name of the certificate store for the client certificate.
ssh_cert_store_passwordIf the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.
ssh_cert_store_typeThis is the type of certificate store for this certificate.
ssh_cert_subjectThis is the subject of the certificate used for client authentication.
ssh_compression_algorithmsA comma-separated list containing all allowable compression algorithms.
ssh_encryption_algorithmsA comma-separated list containing all allowable encryption algorithms.

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_lengthChanges the length of received data records.
close_channelCloses a existing SSHChannel .
configSets or retrieves a configuration setting.
disconnectThis method disconnects the specified client.
do_eventsProcesses events from the internal message queue.
exchange_keysCauses the class to exchange a new set of session keys on the specified connection.
get_ssh_paramUsed to read a field from an SSH packet's payload.
get_ssh_param_bytesUsed to read a field from an SSH packet's payload.
open_channelOpens a new SSHChannel .
resetReset the class.
send_bytesSends binary data to the specified channel.
send_channel_dataUsed to send data over an SSH channel.
send_ssh_packetUsed to send an encoded SSH packet to the server.
send_textSends text to the specified channel.
set_ssh_paramUsed to write a field to the end of a payload.
shutdownThis method shuts down the server.
start_listeningThis method starts listening for incoming connections.
stop_listeningThis method stops listening for new connections.

Event List


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

on_connectedThis event is fired immediately after a connection completes (or fails).
on_connection_requestThis event is fired when a request for connection comes from a remote host.
on_disconnectedThis event is fired when a connection is closed.
on_errorInformation about errors during data delivery.
on_logFires once for each log message.
on_ssh_channel_closedFired when a channel is closed.
on_ssh_channel_data_inFired when data is received on an SSH channel.
on_ssh_channel_eofFired when the remote peer signals the end of the data stream for the channel.
on_ssh_channel_openedFired when a channel is successfully opened.
on_ssh_channel_open_requestFired when a client attempts to open a new channel.
on_ssh_channel_ready_to_sendFired when the class is ready to send data.
on_ssh_channel_requestFired when the SSHHost sends a channel request to the client.
on_ssh_channel_requestedFired if the SSHChannelRequest was successful, any further processing for the channel request should be done here.
on_ssh_service_requestFired when a client requests a service to be started.
on_ssh_statusShows the progress of the secure connection.
on_ssh_tunnel_closedThis event will fire when a connected client attempts to close a tunnel.
on_ssh_tunnel_requestedThis event fires when a connected client attempts to establish a forward or reverse tunnel.
on_ssh_user_auth_requestFires when a client attempts to authenticate a connection.

Config Settings


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

AltSSHCertCountThe number of records in the AltSSHCert configuration settings.
AltSSHCertStore[i]The name of the certificate store.
AltSSHCertStorePassword[i]The password used to open the certificate store.
AltSSHCertStoreType[i]The type of certificate store.
AltSSHCertSubject[i]The alternative certificate subject.
ClientSSHVersionString[ConnectionId]The client's version string.
FireAuthRequestAfterSigWhether to fire an informational event after the public key signature has been verified.
KeyboardInteractivePrompts[ConnectionId]Specifies custom keyboard-interactive prompts for particular connections.
KeyRenegotiationThresholdSets the threshold for the SSH Key Renegotiation.
LogLevelSpecifies the level of detail that is logged.
MaxAuthAttemptsThe maximum authentication attempts allowed before forcing a disconnect.
NegotiatedStrictKex[ConnectionId]Returns whether strict key exchange was negotiated to be used.
ServerSSHVersionStringThe SSH version string sent to connecting clients.
SSHKeepAliveCountMaxThe maximum number of keep alive packets to send without a response.
SSHKeepAliveIntervalThe interval between keep alive packets.
SSHKeyExchangeAlgorithmsSpecifies the supported key exchange algorithms.
SSHMacAlgorithmsSpecifies the supported Mac algorithms.
SSHPubKeyAuthSigAlgorithmsSpecifies the allowed signature algorithms used by a client performing public key authentication.
SSHPublicKeyAlgorithmsSpecifies the supported public key algorithms for the server's public key.
SSHVersionPatternThe pattern used to match the remote host's version string.
UserAuthBanner[ConnectionId]A custom user authentication banner.
UseStrictKeyExchangeSpecifies how strict key exchange is supported.
AllowedClientsA comma-separated list of host names or IP addresses that can access the class.
BindExclusivelyWhether or not the class considers a local port reserved for exclusive use.
BlockedClientsA comma-separated list of host names or IP addresses that cannot access the class.
ConnectionUIDThe unique connectionId for a connection.
DefaultConnectionTimeoutThe inactivity timeout applied to the SSL handshake.
InBufferSizeThe size in bytes of the incoming queue of the socket.
KeepAliveIntervalThe retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.
KeepAliveRetryCountThe number of keep-alive packets to be sent before the remotehost is considered disconnected.
KeepAliveTimeThe inactivity time in milliseconds before a TCP keep-alive packet is sent.
MaxConnectionsThe maximum number of connections available.
MaxReadTimeThe maximum time spent reading data from each connection.
OutBufferSizeThe size in bytes of the outgoing queue of the socket.
TcpNoDelayWhether or not to delay when sending packets.
UseIOCPWhether to use the completion port I/O model.
UseIPv6Whether to use IPv6.
UseWindowsMessagesWhether to use the WSAAsyncSelect I/O model.
BuildInfoInformation about the product's build.
CodePageThe system code page used for Unicode to Multibyte translations.
LicenseInfoInformation about the current license.
MaskSensitiveWhether sensitive data is masked in log messages.
ProcessIdleEventsWhether the class uses its internal event loop to process events when the main thread is idle.
SelectWaitMillisThe length of time in milliseconds the class will wait when DoEvents is called if there are no events to process.
UseFIPSCompliantAPITells the class whether or not to use FIPS certified APIs.
UseInternalSecurityAPIWhether or not to use the system security libraries or an internal implementation.

ssh_channel_count Property

The number of records in the arrays.

Syntax

def get_ssh_channel_count() -> int: ...

ssh_channel_count = property(get_ssh_channel_count, None)

Default Value

0

Remarks

This property controls the size of the following arrays:

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

This property is read-only.

bytes_sent Property

The number of bytes actually sent after a sending channel data.

Syntax

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

Default Value

0

Remarks

The number of bytes actually sent after a sending channel data.

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is read-only.

channel_id Property

An id generated by the class to identify the current SSH channel.

Syntax

def get_channel_id(ssh_channel_id: int) -> str: ...

Default Value

""

Remarks

An id generated by the class to identify the current SSH channel. This id is unique to this channel.

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is read-only.

data_to_send Property

A string of data to be sent to the remote host.

Syntax

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

Default Value

""

Remarks

A string of data to be sent to the remote host. Write-only property.

Assigning a string to the datatosend makes the class send the string to the remote host.

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

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is write-only.

ready_to_send Property

This property is True when data can be sent over the SSH Channel.

Syntax

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

Default Value

FALSE

Remarks

This property is True when data can be sent over the SSH Channel.

When timeout is set to 0 (asynchronous) sending data may result in an error if the channel or underlying socket cannot accept more data to send. Monitor onsshchannelreadytosend or readytosend to determine when data can be sent again.

When timeout is set to a positive value the class will block when sending data until the data can be successfully sent and onsshchannelreadytosend and readytosend do not need to be monitored.

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is read-only.

record_length Property

The length of received data records.

Syntax

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

Default Value

0

Remarks

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

The default value is 0, meaning this setting is not used.

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

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

service Property

This property holds the channel type that was requested when opening the channel.

Syntax

def get_service(ssh_channel_id: int) -> str: ...

Default Value

""

Remarks

This property holds the channel type that was requested when opening the channel. For instance "session" or "forwarded-tcpip".

The ssh_channel_id parameter specifies the index of the item in the array. The size of the array is controlled by the ssh_channel_count property.

This property is read-only.

connection_backlog Property

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

Syntax

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

connection_backlog = property(get_connection_backlog, set_connection_backlog)

Default Value

5

Remarks

This property contains the maximum number of pending connections maintained by the TCP/IP subsystem. This value reflects the SOMAXCONN option for the main listening socket. The default value for most systems is 5. You may set this property to a larger value if the server is expected to receive a large number of connections, and queuing them is desirable.

ssh_connection_count Property

The number of records in the SSHConnection arrays.

Syntax

def get_ssh_connection_count() -> int: ...

ssh_connection_count = property(get_ssh_connection_count, None)

Default Value

0

Remarks

This property controls the size of the following arrays:

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

This property is read-only.

ssh_connection_connected Property

Used to disconnect individual connections and/or show their status.

Syntax

def get_ssh_connection_connected(connection_id: int) -> bool: ...
def set_ssh_connection_connected(connection_id: int, value: bool) -> None: ...

Default Value

FALSE

Remarks

Used to disconnect individual connections and/or show their status.

The connected is used to close connections.

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

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

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

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

ssh_connection_local_address Property

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

Syntax

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

Default Value

""

Remarks

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

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

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

This property is read-only.

ssh_connection_remote_host Property

The RemoteHost shows the IP address of the remote host through which the connection is coming.

Syntax

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

Default Value

""

Remarks

The remotehost 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 ssh_connection_count property.

This property is read-only.

ssh_connection_remote_port Property

The RemotePort shows the TCP port on the remote host through which the connection is coming.

Syntax

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

Default Value

0

Remarks

The remoteport shows the 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 ssh_connection_count property.

This property is read-only.

ssh_connection_timeout Property

A timeout for the class.

Syntax

def get_ssh_connection_timeout(connection_id: int) -> int: ...
def set_ssh_connection_timeout(connection_id: int, value: int) -> None: ...

Default Value

0

Remarks

A timeout for the class.

If the timeout property is set to 0, all operations return immediately, potentially failing with an 'WOULDBLOCK' error if data can't be sent or received immediately.

If timeout is set to a positive value, the class will automatically retry each operation that would otherwise result in a 'WOULDBLOCK' error for a maximum of timeout seconds.

The class will use doevents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not "freeze" and remains responsive.

If timeout expires, and the operation is not yet complete, the class fails with an error.

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

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

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

default_auth_methods Property

Specifies the supported authentication methods.

Syntax

def get_default_auth_methods() -> str: ...
def set_default_auth_methods(value: str) -> None: ...

default_auth_methods = property(get_default_auth_methods, set_default_auth_methods)

Default Value

"password,publickey"

Remarks

This property specifies the supported authentication methods. The client will choose one of the supported mechanisms when authenticating to the class.

This must be a comma separated list of values. For more information on authenticating clients see the on_ssh_user_auth_request event.

The following is a list of methods implemented by the class:

noneThis authentication method is used by most SSH clients to obtain the list of authentication methods available for the user's account. In most cases you should not accept a request using this authentication method.
passwordAuthParam will contain the user-supplied password. If the password is correct, set Accept to true.
publickeyAuthParam will contain an SSH2 public key blob. If the user's public key is acceptable, set Accept or PartialSuccess to True. The class will then handle verifying the digital signature and will respond to the client accordingly.
keyboard-interactiveon_ssh_user_auth_request will fire multiple times for keyboard-interactive authentication: It will fire once for each response sent by the client in the SSH_MSG_USERAUTH_INFO_RESPONSE packet (one for each prompt specified by the daemon). The index of each response will be specified as a suffix in AuthMethod, with AuthParam containing the response to the corresponding prompt (e.g keyboard-interactive-1, keyboard-interactive-2 and so on). Finally, on_ssh_user_auth_request will fire one last time with AuthMethod set to "keyboard-interactive" and AuthParam set to an empty string. The daemon must set Accept to true every time to allow the authentication process to succeed.

default_idle_timeout Property

This property includes the default idle timeout for inactive clients.

Syntax

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

default_idle_timeout = property(get_default_idle_timeout, set_default_idle_timeout)

Default Value

0

Remarks

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

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

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

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

default_timeout Property

An initial timeout value to be used by incoming connections.

Syntax

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

default_timeout = property(get_default_timeout, set_default_timeout)

Default Value

60

Remarks

This property is used by the class to set the operational timeout value of all inbound connections once they are established. If the timeout is set to 0, all inbound connections will behave asynchronously. The default value is 60, meaning the class will behave synchronously.

keyboard_interactive_message Property

The instructions to send to the client during keyboard-interactive authentication.

Syntax

def get_keyboard_interactive_message() -> str: ...
def set_keyboard_interactive_message(value: str) -> None: ...

keyboard_interactive_message = property(get_keyboard_interactive_message, set_keyboard_interactive_message)

Default Value

""

Remarks

This property should be set to the main instructions to send to the client during keyboard-interactive authentication.

keyboard_interactive_prompt_count Property

The number of records in the KeyboardInteractivePrompt arrays.

Syntax

def get_keyboard_interactive_prompt_count() -> int: ...
def set_keyboard_interactive_prompt_count(value: int) -> None: ...

keyboard_interactive_prompt_count = property(get_keyboard_interactive_prompt_count, set_keyboard_interactive_prompt_count)

Default Value

0

Remarks

This property controls the size of the following arrays:

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

keyboard_interactive_prompt_echo Property

Specifies if the client should echo the value entered by the user or not.

Syntax

def get_keyboard_interactive_prompt_echo(prompt_index: int) -> bool: ...
def set_keyboard_interactive_prompt_echo(prompt_index: int, value: bool) -> None: ...

Default Value

FALSE

Remarks

Specifies if the client should echo the value entered by the user or not.

The prompt_index parameter specifies the index of the item in the array. The size of the array is controlled by the keyboard_interactive_prompt_count property.

keyboard_interactive_prompt_prompt Property

The prompt label/text the client should present to the user.

Syntax

def get_keyboard_interactive_prompt_prompt(prompt_index: int) -> str: ...
def set_keyboard_interactive_prompt_prompt(prompt_index: int, value: str) -> None: ...

Default Value

""

Remarks

The prompt label/text the client should present to the user.

The prompt_index parameter specifies the index of the item in the array. The size of the array is controlled by the keyboard_interactive_prompt_count property.

listening Property

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

Syntax

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

listening = property(get_listening, set_listening)

Default Value

FALSE

Remarks

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

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

local_host Property

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

Syntax

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

local_host = property(get_local_host, set_local_host)

Default Value

""

Remarks

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

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

If the class is connected, the local_host property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multi-homed hosts (machines with more than one IP interface).

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

local_port Property

The TCP port in the local host where the class listens.

Syntax

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

local_port = property(get_local_port, set_local_port)

Default Value

22

Remarks

The local_port property must be set before TCPServer starts 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 the local_port property after TCPServer is in listening mode (after successfully assigning True to the listening property).

The service port is not shared among servers (i.e. there can be only one TCPServer 'listening' on a particular port at one time).

ssh_cert_encoded Property

This is the certificate (PEM/Base64 encoded).

Syntax

def get_ssh_cert_encoded() -> bytes: ...
def set_ssh_cert_encoded(value: bytes) -> None: ...

ssh_cert_encoded = property(get_ssh_cert_encoded, set_ssh_cert_encoded)

Default Value

""

Remarks

This is the certificate (PEM/Base64 encoded). This property is used to assign a specific certificate. The store and subject properties also may be used to specify a certificate.

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

ssh_cert_store Property

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

Syntax

def get_ssh_cert_store() -> bytes: ...
def set_ssh_cert_store(value: bytes) -> None: ...

ssh_cert_store = property(get_ssh_cert_store, set_ssh_cert_store)

Default Value

"MY"

Remarks

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

The storetype property denotes the type of the certificate store specified by store. If the store is password protected, specify the password in storepassword.

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

Designations of certificate stores are platform dependent.

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

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

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

ssh_cert_store_password Property

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

Syntax

def get_ssh_cert_store_password() -> str: ...
def set_ssh_cert_store_password(value: str) -> None: ...

ssh_cert_store_password = property(get_ssh_cert_store_password, set_ssh_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.

ssh_cert_store_type Property

This is the type of certificate store for this certificate.

Syntax

def get_ssh_cert_store_type() -> int: ...
def set_ssh_cert_store_type(value: int) -> None: ...

ssh_cert_store_type = property(get_ssh_cert_store_type, set_ssh_cert_store_type)

Default Value

0

Remarks

This is the type of certificate store for this certificate.

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

0 (cstUser - default)For Windows, this specifies that the certificate store is a certificate store owned by the current user.

Note: This store type is not available in Java.

1 (cstMachine)For Windows, this specifies that the certificate store is a machine store.

Note: This store type is not available in Java.

2 (cstPFXFile)The certificate store is the name of a PFX (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, the necessary data must first be collected using the CertMgr class. The liststorecertificates method may be called after setting certstoretype to cstPKCS11, certstorepassword to the PIN, and certstore to the full path of the PKCS#11 DLL. The certificate information returned in the oncertlist event's CertEncoded parameter may be saved for later use.

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

Code Example. SSH Authentication with Security Key: certmgr.CertStoreType = CertStoreTypes.cstPKCS11; certmgr.OnCertList += (s, e) => { secKeyBlob = e.CertEncoded; }; certmgr.CertStore = @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll"; certmgr.CertStorePassword = "123456"; //PIN certmgr.ListStoreCertificates(); sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11, secKeyBlob, "123456", "*"); sftp.SSHUser = "test"; sftp.SSHLogon("myhost", 22);

99 (cstAuto)The store type is automatically detected from the input data. This setting may be used with both public and private keys and can detect any of the supported formats automatically.

ssh_cert_subject Property

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

Syntax

def get_ssh_cert_subject() -> str: ...
def set_ssh_cert_subject(value: str) -> None: ...

ssh_cert_subject = property(get_ssh_cert_subject, set_ssh_cert_subject)

Default Value

""

Remarks

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

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

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

If an exact match is not found, the store is searched for subjects containing the value of the property.

If a match is still not found, the property is set to an empty string, and no certificate is selected.

The special value "*" picks a random certificate in the certificate store.

The certificate subject is a comma-separated list of distinguished name fields and values. For instance, "CN=www.server.com, OU=test, C=US, E=support@nsoftware.com". Common fields and their meanings are as follows:

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

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

ssh_compression_algorithms Property

A comma-separated list containing all allowable compression algorithms.

Syntax

def get_ssh_compression_algorithms() -> str: ...
def set_ssh_compression_algorithms(value: str) -> None: ...

ssh_compression_algorithms = property(get_ssh_compression_algorithms, set_ssh_compression_algorithms)

Default Value

"none,zlib"

Remarks

During the SSH handshake, this list will be used to negotiate the compression algorithm to be used between the client and server. This list is used for both directions: client to server and server to client. When negotiating algorithms, each side sends a list of all algorithms it supports or allows. The algorithm chosen for each direction is the first algorithm to appear in the sender's list that the receiver supports, so it is important to list multiple algorithms in preferential order. If no algorithm can be agreed upon, the class will raise an error and the connection will be aborted.

At least one supported algorithm must appear in this list. The following compression algorithms are supported by the class:

  • zlib
  • zlib@openssh.com
  • none

ssh_encryption_algorithms Property

A comma-separated list containing all allowable encryption algorithms.

Syntax

def get_ssh_encryption_algorithms() -> str: ...
def set_ssh_encryption_algorithms(value: str) -> None: ...

ssh_encryption_algorithms = property(get_ssh_encryption_algorithms, set_ssh_encryption_algorithms)

Default Value

"aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,3des-ctr,3des-cbc,blowfish-cbc,arcfour256,arcfour128,arcfour,cast128-cbc,aes256-gcm@openssh.com,aes128-gcm@openssh.com,chacha20-poly1305@openssh.com"

Remarks

During the SSH handshake, this list will be used to negotiate the encryption algorithm to be used between the client and server. This list is used for both directions: client to server and server to client. When negotiating algorithms, each side sends a list of all algorithms it supports or allows. The algorithm chosen for each direction is the first algorithm to appear in the sender's list that the receiver supports, so it is important to list multiple algorithms in preferential order. If no algorithm can be agreed upon, the class will raise an error and the connection will be aborted.

At least one supported algorithm must appear in this list. The following encryption algorithms are supported by the class:

aes256-ctr256-bit AES encryption in CTR mode
aes256-cbc256-bit AES encryption in CBC mode
aes192-ctr192-bit AES encryption in CTR mode
aes192-cbc192-bit AES encryption in CBC mode
aes128-ctr128-bit AES encryption in CTR mode
aes128-cbc128-bit AES encryption in CBC mode
3des-ctr192-bit (3-key) triple DES encryption in CTR mode
3des-cbc192-bit (3-key) triple DES encryption in CBC mode
cast128-cbcCAST-128 encryption
blowfish-cbcBlowfish encryption
arcfourARC4 encryption
arcfour128128-bit ARC4 encryption
arcfour256256-bit ARC4 encryption
aes256-gcm@openssh.com256-bit AES encryption in GCM mode.
aes128-gcm@openssh.com128-bit AES encryption in GCM mode.
chacha20-poly1305@openssh.comChaCha20 with Poly1305-AES encryption.

change_record_length Method

Changes the length of received data records.

Syntax

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

Remarks

This method defines the length of data records to be received (in bytes) for the specified ChannelId.

If RecordLength is set to a positive value, the class will accumulate data until RecordLength bytes of data is received and only then fire the on_ssh_channel_data_in event with data of length RecordLength. This allows data to be received as records of known length. This method can be called at any time to change the record length, including within the on_data_in event.

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

close_channel Method

Closes a existing SSHChannel .

Syntax

def close_channel(channel_id: int) -> None: ...

Remarks

ChannelId is the identifier for the SSH channel to be closed.

config Method

Sets or retrieves a configuration setting.

Syntax

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

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

disconnect Method

This method disconnects the specified client.

Syntax

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

Remarks

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

do_events Method

Processes events from the internal message queue.

Syntax

def do_events() -> None: ...

Remarks

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

exchange_keys Method

Causes the class to exchange a new set of session keys on the specified connection.

Syntax

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

Remarks

SSH key renegotiation can be initiated by either end of an established SSH connection. exchange_keys allows the server to start such a renegotiation with the client. During this process, on_ssh_status events will fire containing updates regarding the key negotiation process.

The SSH 2.0 specification recommends that key renegotiation be done once for 2 gigabytes (GB) of data processed by the connection, or once every day. This makes it more difficult to break the security of data-intensive or long-lived connections.

get_ssh_param Method

Used to read a field from an SSH packet's payload.

Syntax

def get_ssh_param(payload: bytes, field: str) -> str: ...

Remarks

This method is used to read the value of a particular field from an SSH packet's payload. Payload should contain the full payload of a packet received by an event such as on_ssh_channel_request. Field is the name of a field to be read out of the packet.

The following is a list of the names of well-known channel request field names and their encodings:

ChannelId (int32)The id of the channel that received the packet.
RequestType (string)The type of channel request.
WantsReply (boolean)Whether or not the client wants a reply to the request.

The remaining fields that are available in the payload are dependent upon the value of RequestType.

pty-req

Pty-req is a request to open a pseudo terminal on the specified channel. The following fields are available:

TerminalType (string)The type of terminal being requested (eg: "vt100").
TerminalWidthCharacters (int32)The width, in characters, of the terminal to be opened.
TerminalHeightRows (int32)The height, in rows, of the terminal to be opened.
TerminalWidthPixels (int32)The width, in pixels, of the terminal to be opened.
TerminalHeightPixels (int32)The height, in pixels, of the terminal to be opened.
TerminalModes (string)A list of op-val (int32-byte) encoded modes to be used by the terminal.

x11-req

X11-req is a request to forward x11 sessions over a channel. The following fields are available:

SingleConnection (boolean)Disallows more than one connection to be forwarded by the channel.
X11AuthProtocol (string)The authentication protocol to be used (eg: "MIT-MAGIC-COOKIE-1").
X11AuthCookie (string)A hexadecimal-encoded cookie to be used for authentication.
X11ScreenNumber (int32)The x11 screen number to be used.

env

Env is a request to set an environment variable to be passed into a shell that may be started later. The following fields are available:

VariableName (string)The name of the variable to be set.
VariableValue (string)The value of the variable to be set.

exec

Exec is a request to execute a command on the channel using the authenticated user's shell. The following field is available:

Command (string)The command to be executed.

subsystem

Subsystem is a request to start a subsystem on the specified channel. The following field is available:

Subsystem (string)The name of the subsystem to be started (eg: "sftp").

xon-xoff

Instructs the server to allow or disallow control-S/control-Q style flow control. The following field is available:

ClientCanDo (boolean)Whether or not the server should enable flow control.

signal

Sends a signal to the remote process/service. The following field is available:

SignalName (string)The name of the signal to be sent.

If the packet type is not well known, Field should start with the special character "%" and contain a comma-separated list of field types as defined in set_ssh_param. For example, reading out the X11AuthProtocol of an x11-req payload, you can use "%s,f".

Note: the return value is a string encoded the same way as the FieldValue param in set_ssh_param.

get_ssh_param_bytes Method

Used to read a field from an SSH packet's payload.

Syntax

def get_ssh_param_bytes(payload: bytes, field: str) -> bytes: ...

Remarks

This method is the same as calling get_ssh_param, but returns raw bytes instead of strings.

open_channel Method

Opens a new SSHChannel .

Syntax

def open_channel(connection_id: int, channel_type: str) -> str: ...

Remarks

The SSH 2.0 specification allows for multiple channels to be opened over a single TCP/IP connection. The channels property represents the channels that are currently open. A new SSHChannel can be opened with open_channel.

ChannelType represents the type of SSH channel to be opened. The most common type of channel is "session".

If the call to open_channel succeeds, an SSHChannel will be created and added to the channels collection.

reset Method

Reset the class.

Syntax

def reset() -> None: ...

Remarks

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

send_bytes Method

Sends binary data to the specified channel.

Syntax

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

Remarks

This method sends binary data to the channel identified by ChannelId. To send text use the send_text method instead.

send_channel_data Method

Used to send data over an SSH channel.

Syntax

def send_channel_data(channel_id: int, data: bytes) -> None: ...

Remarks

This method can be used to send arbitrary data to the channel with the specified ChannelId.

send_ssh_packet Method

Used to send an encoded SSH packet to the server.

Syntax

def send_ssh_packet(channel_id: int, packet_type: int, payload: bytes) -> None: ...

Remarks

This method can be used to send a previously built SSH payload to the server. ChannelId identifies the channel that will receive the packet.

PacketType identifies what kind of packet is to be sent. Payload should contain the payload of the packet, which can be built by successive calls to set_ssh_param.

When send_ssh_packet is called, the class will finish building the packet, encrypt it for transport, and send it to the server.

send_text Method

Sends text to the specified channel.

Syntax

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

Remarks

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

set_ssh_param Method

Used to write a field to the end of a payload.

Syntax

def set_ssh_param(payload: bytes, field_type: str, field_value: str) -> bytes: ...

Remarks

This method is used to build the payload portion of an SSH packet to be sent later by a call to send_ssh_packet. Payload should contain the result of a previous call to set_ssh_param. FieldType is a string defining the type of field to be written to the packet. FieldValue should be the string representation of the field to be written.

The following is a list of supported field types and a description of how FieldValue should be encoded:

sA plaintext string containing the default system encoding of the data.
sbA string containing the hex encoded data. (eg: "A1B23C")
mA variable-length large integer, encoded as a textual representation of the value ("1234").
iA 32-bit integer, encoded as a textual representation of the value (eg: "1234").
lA 64-bit integer, encoded as a textual representation of the value (eg: "1234").
bA single byte, encoded as a textual representation of the value (eg: "123").
fA boolean flag, encoded as a textual representation of the value (eg: 'true' or 'false')

Note: integer values may be encoded in hexadecimal by prefixing "0x" to the beginning of the string, otherwise the value is assumed to be base-10.

shutdown Method

This method shuts down the server.

Syntax

def shutdown() -> None: ...

Remarks

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

start_listening Method

This method starts listening for incoming connections.

Syntax

def start_listening() -> None: ...

Remarks

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

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

stop_listening Method

This method stops listening for new connections.

Syntax

def stop_listening() -> None: ...

Remarks

This method stops listening for new connections. After being called, any new connection attempts will be rejected. Calling this method does not disconnect existing connections.

To stop listening and to disconnect all existing clients, call shutdown instead.

on_connected Event

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

Syntax

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

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

  @property
  def description() -> 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 SSHServer:
@property
def on_connected() -> Callable[[SSHServerConnectedEventParams], None]: ...
@on_connected.setter
def on_connected(event_hook: Callable[[SSHServerConnectedEventParams], None]) -> None: ...

Remarks

If the connection is made normally, StatusCode is 0, and Description is "OK".

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

Please refer to the Error Codes section for more information.

ConnectionId is the connection Id of the client requesting the connection.

CertStoreType is the store type of the alternate certificate to use for this connection. The class supports both public and private keys in a variety of formats. When the cstAuto value is used, the class will automatically determine the type. This property can take one of the following values:

0 (cstUser - default)For Windows, this specifies that the certificate store is a certificate store owned by the current user.

Note: This store type is not available in Java.

1 (cstMachine)For Windows, this specifies that the certificate store is a machine store.

Note: This store type is not available in Java.

2 (cstPFXFile)The certificate store is the name of a PFX (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, the necessary data must first be collected using the CertMgr class. The list_store_certificates method may be called after setting cert_store_type to cstPKCS11, cert_store_password to the PIN, and cert_store to the full path of the PKCS#11 DLL. The certificate information returned in the on_cert_list event's CertEncoded parameter may be saved for later use.

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

Code Example. SSH Authentication with Security Key: certmgr.CertStoreType = CertStoreTypes.cstPKCS11; certmgr.OnCertList += (s, e) => { secKeyBlob = e.CertEncoded; }; certmgr.CertStore = @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll"; certmgr.CertStorePassword = "123456"; //PIN certmgr.ListStoreCertificates(); sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11, secKeyBlob, "123456", "*"); sftp.SSHUser = "test"; sftp.SSHLogon("myhost", 22);

99 (cstAuto)The store type is automatically detected from the input data. This setting may be used with both public and private keys and can detect any of the supported formats automatically.

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

Designations of certificate stores are platform dependent.

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

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

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

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

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

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

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

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

on_connection_request Event

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

Syntax

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

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

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

# In class SSHServer:
@property
def on_connection_request() -> Callable[[SSHServerConnectionRequestEventParams], None]: ...
@on_connection_request.setter
def on_connection_request(event_hook: Callable[[SSHServerConnectionRequestEventParams], 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_disconnected Event

This event is fired when a connection is closed.

Syntax

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

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

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

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

Remarks

If the connection is broken normally, StatusCode is 0, and Description is "OK".

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

Please refer to the Error Codes section for more information.

on_error Event

Information about errors during data delivery.

Syntax

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

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

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

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

Remarks

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

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

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

on_log Event

Fires once for each log message.

Syntax

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

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

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

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

# In class SSHServer:
@property
def on_log() -> Callable[[SSHServerLogEventParams], None]: ...
@on_log.setter
def on_log(event_hook: Callable[[SSHServerLogEventParams], None]) -> None: ...

Remarks

This event fires once for each log messages generated by the class. The verbosity is controlled by the LogLevel setting.

LogLevel indicates the detail level of the message. Possible values are:

0 (None) No messages are logged.
1 (Info - Default) Informational events such as SSH handshake messages are logged.
2 (Verbose) Detailed data such as individual packet information is logged.
3 (Debug) Debug data including all relevant sent and received bytes are logged.

Message is the log message.

LogType is reserved for future use.

ConnectionId specifies the connection to which the log message is applicable.

on_ssh_channel_closed Event

Fired when a channel is closed.

Syntax

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

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

# In class SSHServer:
@property
def on_ssh_channel_closed() -> Callable[[SSHServerSSHChannelClosedEventParams], None]: ...
@on_ssh_channel_closed.setter
def on_ssh_channel_closed(event_hook: Callable[[SSHServerSSHChannelClosedEventParams], None]) -> None: ...

Remarks

The on_ssh_channel_closed event is fired when a channel is closed on an SSH connection.

ConnectionId identifies the connection. ChannelId identifies the channel.

Note: Processing long-running requests, including sending channel data, inside this event may cause the underlying transport to stop processing SSH data until the event returns. In order to prevent this from happening, all requests should be processed asynchronously in a separate thread outside of this event.

on_ssh_channel_data_in Event

Fired when data is received on an SSH channel.

Syntax

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

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

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

# In class SSHServer:
@property
def on_ssh_channel_data_in() -> Callable[[SSHServerSSHChannelDataInEventParams], None]: ...
@on_ssh_channel_data_in.setter
def on_ssh_channel_data_in(event_hook: Callable[[SSHServerSSHChannelDataInEventParams], None]) -> None: ...

Remarks

Whenever a client sends data to an SSH channel, the on_ssh_channel_data_in event will fire. ChannelId will identify the channel receiving data. Data will contain the raw data being received.

ConnectionId identifies the connection. ChannelId identifies the channel.

Note: Processing long-running requests, including sending channel data, inside this event may cause the underlying transport to stop processing SSH data until the event returns. In order to prevent this from happening, all requests should be processed asynchronously in a separate thread outside of this event.

on_ssh_channel_eof Event

Fired when the remote peer signals the end of the data stream for the channel.

Syntax

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

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

# In class SSHServer:
@property
def on_ssh_channel_eof() -> Callable[[SSHServerSSHChannelEOFEventParams], None]: ...
@on_ssh_channel_eof.setter
def on_ssh_channel_eof(event_hook: Callable[[SSHServerSSHChannelEOFEventParams], None]) -> None: ...

Remarks

The on_ssh_channel_eof event is fired when the end of the data stream for a channel on an SSH connection is reached.

ConnectionId identifies the connection. ChannelId identifies the channel.

Note: Processing long-running requests, including sending channel data, inside this event may cause the underlying transport to stop processing SSH data until the event returns. In order to prevent this from happening, all requests should be processed asynchronously in a separate thread outside of this event.

on_ssh_channel_opened Event

Fired when a channel is successfully opened.

Syntax

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

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

# In class SSHServer:
@property
def on_ssh_channel_opened() -> Callable[[SSHServerSSHChannelOpenedEventParams], None]: ...
@on_ssh_channel_opened.setter
def on_ssh_channel_opened(event_hook: Callable[[SSHServerSSHChannelOpenedEventParams], None]) -> None: ...

Remarks

The on_ssh_channel_opened event is fired when a channel is successfully opened on an SSH connection.

ConnectionId identifies the connection. ChannelId identifies the channel.

Note: Processing long-running requests, including sending channel data, inside this event may cause the underlying transport to stop processing SSH data until the event returns. In order to prevent this from happening, all requests should be processed asynchronously in a separate thread outside of this event.

on_ssh_channel_open_request Event

Fired when a client attempts to open a new channel.

Syntax

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

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

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

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

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

# In class SSHServer:
@property
def on_ssh_channel_open_request() -> Callable[[SSHServerSSHChannelOpenRequestEventParams], None]: ...
@on_ssh_channel_open_request.setter
def on_ssh_channel_open_request(event_hook: Callable[[SSHServerSSHChannelOpenRequestEventParams], None]) -> None: ...

Remarks

This event is fired whenever a client attempts to open a new channel for a given connection. ChannelId will contain the id of the channel to be created. Service will identify the type of channel that is being requested (e.g.: "session"). Set Accept to true to accept the channel open request.

ConnectionId identifies the connection. ChannelId identifies the channel.

If the channel open request contains extra information, it will be contained in Parameters; you can extract data from it using get_ssh_param and get_ssh_param_bytes. The most common example of a request with parameters would be a request with Service set to "direct-tcpip" (for SSH tunneling); in that case Parameters will contain the host to connect (string), the port to connect (int), the originator IP address (string) and the originator TCP port (int).

Note: Processing long-running requests, including sending channel data, inside this event may cause the underlying transport to stop processing SSH data until the event returns. In order to prevent this from happening, all requests should be processed asynchronously in a separate thread outside of this event.

on_ssh_channel_ready_to_send Event

Fired when the class is ready to send data.

Syntax

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

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

# In class SSHServer:
@property
def on_ssh_channel_ready_to_send() -> Callable[[SSHServerSSHChannelReadyToSendEventParams], None]: ...
@on_ssh_channel_ready_to_send.setter
def on_ssh_channel_ready_to_send(event_hook: Callable[[SSHServerSSHChannelReadyToSendEventParams], None]) -> None: ...

Remarks

This event fires when data can be sent over the SSH Channel specified by ChannelId for the connection specified by ConnectionId.

When a channel is opened this event will fire once the channel is ready and data can be sent.

When timeout is set to 0 (asynchronous) sending data may result in an error if the channel or underlying socket cannot accept more data to send. Monitor on_ssh_channel_ready_to_send or ready_to_send to determine when data can be sent again.

When timeout is set to a positive value the class will block when sending data until the data can be successfully sent and on_ssh_channel_ready_to_send and ready_to_send do not need to be monitored.

on_ssh_channel_request Event

Fired when the SSHHost sends a channel request to the client.

Syntax

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

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

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

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

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

# In class SSHServer:
@property
def on_ssh_channel_request() -> Callable[[SSHServerSSHChannelRequestEventParams], None]: ...
@on_ssh_channel_request.setter
def on_ssh_channel_request(event_hook: Callable[[SSHServerSSHChannelRequestEventParams], None]) -> None: ...

Remarks

The ssh_host may send requests that affect the status of a particular SSHChannel. Some requests will be automatically handled by the class. However, others may need the attention of the user to be dealt with properly within the scope of the application.

ConnectionId identifies the connection.

ChannelId identifies the channel receiving the request.

Type will contain the type of the request. These types are dependent upon the type of the channel. For example, a "session" channel executing a command on the remote shell may receive an "exit-status" request containing the return code of that command.

RequestData contains the remainder of the original SSH packet. If the request type has specific parameters, they can be parsed out of this data.

Success should be used to instruct the class to respond to the request with either a success or failure notification. If the request is successful, on_ssh_channel_requested will fire with the same information in case the request requires further processing.

Note: Processing long-running requests, including sending channel data, inside this event may cause the underlying transport to stop processing SSH data until the event returns. In order to prevent this from happening, all requests should be processed asynchronously in a separate thread outside of this event.

on_ssh_channel_requested Event

Fired if the SSHChannelRequest was successful, any further processing for the channel request should be done here.

Syntax

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

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

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

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

# In class SSHServer:
@property
def on_ssh_channel_requested() -> Callable[[SSHServerSSHChannelRequestedEventParams], None]: ...
@on_ssh_channel_requested.setter
def on_ssh_channel_requested(event_hook: Callable[[SSHServerSSHChannelRequestedEventParams], None]) -> None: ...

Remarks

The ssh_host may send requests that affect the status of a particular SSHChannel. Some requests will be automatically handled by the class. However, others may need the attention of the user to be dealt with properly within the scope of the application.

ConnectionId identifies the connection.

ChannelId identifies the channel receiving the request.

Type will contain the type of the request. These types are dependent upon the type of the channel. For example, a "session" channel executing a command on the remote shell may receive an "exit-status" request containing the return code of that command.

RequestData contains the remainder of the original SSH packet. If the request type has specific parameters, they can be parsed out of this data.

Note: Processing long-running requests, including sending channel data, inside this event may cause the underlying transport to stop processing SSH data until the event returns. In order to prevent this from happening, all requests should be processed asynchronously in a separate thread outside of this event.

on_ssh_service_request Event

Fired when a client requests a service to be started.

Syntax

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

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

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

# In class SSHServer:
@property
def on_ssh_service_request() -> Callable[[SSHServerSSHServiceRequestEventParams], None]: ...
@on_ssh_service_request.setter
def on_ssh_service_request(event_hook: Callable[[SSHServerSSHServiceRequestEventParams], None]) -> None: ...

Remarks

The on_ssh_service_request event is fired when a client requests that a service be started for a particular connection, identified by ConnectionId. Service will be the name of the service the client wishes to start. If the connection is authenticated and the user has access to the service, set Accept to true to allow the SSHServer to accept the request.

Note: Processing long-running requests, including sending channel data, inside this event may cause the underlying transport to stop processing SSH data until the event returns. In order to prevent this from happening, all requests should be processed asynchronously in a separate thread outside of this event.

on_ssh_status Event

Shows the progress of the secure connection.

Syntax

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

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

# In class SSHServer:
@property
def on_ssh_status() -> Callable[[SSHServerSSHStatusEventParams], None]: ...
@on_ssh_status.setter
def on_ssh_status(event_hook: Callable[[SSHServerSSHStatusEventParams], None]) -> None: ...

Remarks

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

on_ssh_tunnel_closed Event

This event will fire when a connected client attempts to close a tunnel.

Syntax

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

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

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

# In class SSHServer:
@property
def on_ssh_tunnel_closed() -> Callable[[SSHServerSSHTunnelClosedEventParams], None]: ...
@on_ssh_tunnel_closed.setter
def on_ssh_tunnel_closed(event_hook: Callable[[SSHServerSSHTunnelClosedEventParams], None]) -> None: ...

Remarks

This event fires when the connected client attempts to close a forward or reverse tunnel.

on_ssh_tunnel_requested Event

This event fires when a connected client attempts to establish a forward or reverse tunnel.

Syntax

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

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

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

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

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

# In class SSHServer:
@property
def on_ssh_tunnel_requested() -> Callable[[SSHServerSSHTunnelRequestedEventParams], None]: ...
@on_ssh_tunnel_requested.setter
def on_ssh_tunnel_requested(event_hook: Callable[[SSHServerSSHTunnelRequestedEventParams], None]) -> None: ...

Remarks

This event fires when the connected client attempts to establish a forward or reverse tunnel. A forward tunnel, after being established, will forward all traffic from the client to a specified hostname and port. A reverse tunnel, after being established, will listen for incoming traffic on the same machine where SSHServer is running and any data received on that port will be forwarded to the client who requested the reverse tunnel.

on_ssh_user_auth_request Event

Fires when a client attempts to authenticate a connection.

Syntax

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

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

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

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

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

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

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

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

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

# In class SSHServer:
@property
def on_ssh_user_auth_request() -> Callable[[SSHServerSSHUserAuthRequestEventParams], None]: ...
@on_ssh_user_auth_request.setter
def on_ssh_user_auth_request(event_hook: Callable[[SSHServerSSHUserAuthRequestEventParams], None]) -> None: ...

Remarks

The on_ssh_user_auth_request event fires when an SSH client attempts to authenticate itself on a particular connection. ConnectionId will identify the connection being authenticated. User will be the name of the account requesting authentication, and Service will contain the name of the service the client is wishing to access.

AuthMethod will denote which method the client is attempting to use to authenticate itself. AuthParam will contain the value of the authentication token used by the client. If the token is acceptable, you may set Accept to true to allow the class to authenticate the client. If it is not, set Accept to false.

Connecting clients will initially attempt authentication with an AuthMethod of "none". This is done with the expectation that the request will fail and the server will send a list of supported methods back to the client. In your implementation check the AuthMethod parameter, if it is "none" you should set AvailableMethods and reject the request. The client will select one of the available methods and re-authenticate.

You may set AvailableMethods to a comma-delimited string of authentication methods that are available for the user. This list will be sent back to the client so that it may perform further authentication attempts.

The following is a list of methods implemented by the class:

noneThis authentication method is used by most SSH clients to obtain the list of authentication methods available for the user's account. In most cases you should not accept a request using this authentication method.
passwordAuthParam will contain the user-supplied password. If the password is correct, set Accept to true.
publickeyAuthParam will contain an SSH2 public key blob. If the user's public key is acceptable, set Accept or PartialSuccess to True. The class will then handle verifying the digital signature and will respond to the client accordingly.
keyboard-interactiveon_ssh_user_auth_request will fire multiple times for keyboard-interactive authentication: It will fire once for each response sent by the client in the SSH_MSG_USERAUTH_INFO_RESPONSE packet (one for each prompt specified by the daemon). The index of each response will be specified as a suffix in AuthMethod, with AuthParam containing the response to the corresponding prompt (e.g keyboard-interactive-1, keyboard-interactive-2 and so on). Finally, on_ssh_user_auth_request will fire one last time with AuthMethod set to "keyboard-interactive" and AuthParam set to an empty string. The daemon must set Accept to true every time to allow the authentication process to succeed.

The PartialSuccess parameter is only used when multi-factor authentication is needed. To implement multi-factor authentication when this event fires first verify the AuthParam for the given AuthMethod. If accepted, set PartialSuccess to true and Accept to false. The client should then send the authentication request for a different form of authentication specified in AvailableMethods. You may continue to set PartialSuccess to true until all authentication requirements are satisfied. Once all requirements are satisfied set Accept to true.

KeyAlgorithm hold the signing algorithm used when the client attempts public key authentication. Possible values are:

  • ssh-rsa
  • rsa-sha2-256
  • rsa-sha2-512
  • ssh-dss
  • ecdsa-sha2-nistp256
  • ecdsa-sha2-nistp384
  • ecdsa-sha2-nistp521
  • x509v3-sign-rsa
  • x509v3-sign-dss

Note: Processing long-running requests, including sending channel data, inside this event may cause the underlying transport to stop processing SSH data until the event returns. In order to prevent this from happening, all requests should be processed asynchronously in a separate thread outside of this event.

SSHServer Config Settings

The class accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the config method.

SSHServer Config Settings

AltSSHCertCount:   The number of records in the AltSSHCert configuration settings.

This configuration setting controls the size of the following arrays:

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

The AltSSHCert configuration settings are used to specify alternative digital certificates to the one set using the ssh_cert. The server will determine the certificate to use during SSH negotiation based on the public key algorithm requested by the connecting client. A certificate with a private key is required for session authentication and encryption. The AltSSHCertSubject setting must be set last. When AltSSHCertSubject is set a search is initiated in the AltSSHCertStore and the certificate is loaded.

These alternative server certificate specified by these settings must be configured prior to setting listening to True. For example: sftpserver.Config("AltSSHCertCount =1"); sftpserver.Config("AltSSHCertStoreType[0]=7"); //PEM Key Blob sftpserver.Config("AltSSHCertStore[0]=" + ed25519Key); //PEM formatted string sftpserver.Config("AltSSHCertSubject[0]=*"); //Load the first (and only) certificate

AltSSHCertStore[i]:   The name of the certificate store.

The name of the certificate store. This is used when specifying an alternative ssh_cert.

The AltSSHCertStoreType specifies the type of the certificate store specified by AltSSHCertStore. IF the store is password protected, specify the password in the AltSSHCertStorePassword.

AltSSHCertStore is used in conjunction with the AltSSHCertSubject field in order to specify the certificate.

Designations of certificate stores are platform dependent.

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

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

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

AltSSHCertStorePassword[i]:   The password used to open the certificate store.

If the certificate store is of a type that requires a password, this setting can be used to specify that password. This is used when specifying an alternative ssh_cert

AltSSHCertStoreType[i]:   The type of certificate store.

This specifies the type of certificate store. This is used when specifying an alternate ssh_cert. Possible values are:

0 User - This is the 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 Machine - For Windows, this specifies that the certificate store is a machine store. Note: This store type is not available in Java.
2 PFXFile - The certificate store is the name of a PFX (PKCS12) file containing certificates.
3 PFXBlob - The certificate store is a string (binary or Base64-encoded) representing a certificate store in PFX (PKCS12) format.
4 JKSFile - The certificate store is the name of a Java Key Store (JKS) file containing certificates. Note: This store type is available only in Java.
5 JKSBlob - 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 available only in Java.
6 PEMKeyFile - The certificate store is the name of a PEM-encoded file that contains a private key and an optional certificate.
7 PEMKeyBlob - The certificate store is a string (binary or Base64-encoded) that contains a private key and an optional certificate.
14 PPKFile - The certificate store is the name of a file that contains a PPK (PuTTY Private Key).
15 PPKBlob - The certificate store is a string (binary) that contains a PPK (PuTTY Private Key).
16 XMLFile - The certificate store is the name of a file that contains a certificate in XML format.
17 XMLBlob - The certificate store is a string that contains a certificate in XML format.
AltSSHCertSubject[i]:   The alternative certificate subject.

The subject of the certificate. This is used when specifying an alternative ssh_cert. The special value of * may be used to select the first certificate in the store.

ClientSSHVersionString[ConnectionId]:   The client's version string.

This setting returns a connected client's SSH version string. It may be queried inside on_ssh_user_auth_request. sftpserver1.OnSSHUserAuthRequest += (obj, ev) => { Console.WriteLine(sftpserver1.Config("ClientSSHVersionString[" + ev.ConnectionId + "]")); };

FireAuthRequestAfterSig:   Whether to fire an informational event after the public key signature has been verified.

When performing public key authentication the connecting client will present both the public key itself as well as a signature to verify ownership of the corresponding private key. The class will automatically verify the signature and respond to the client to indicate whether the signature could be verified and the connection can continue. This setting controls whether an additional informational event fires to report the result of the signature verification.

If set to true, the on_ssh_user_auth_request event will fire twice per public key authentication attempt. The first time the event fires for public key authentication as usual. After verification of the signature has taken place the on_ssh_user_auth_request will fire again, and the AuthMethod parameter will contain the string sigstatus. The AuthParam parameter will contain a value of 0 (invalid signature) or 1 (valid signature). If the signature is invalid it will always result in a rejected authentication attempt.

KeyboardInteractivePrompts[ConnectionId]:   Specifies custom keyboard-interactive prompts for particular connections.

By default, setting the keyboard_interactive_prompts property will cause those prompts to be used for every user attempting to connect. This setting can be used to override the keyboard_interactive_prompts property and provide unique prompts for certain connections.

This setting takes a list of prompts to display to the client, and each prompt includes an 'echo' parameter to specify whether or not to echo the client's response to the prompt. The prompt itself and the echo parameter should be separated by a comma (","), and each prompt should be separated by a semi-colon (";"). For example:

"KeyboardInteractivePrompts[connId]=First prompt,echo=false;Second prompt,echo=true"

This config can be set anywhere in code, but it is necessary to know the ConnectionId for the specific connection beforehand; as such, it is generally recommended to set this config inside the on_ssh_user_auth_request event. Since connecting clients initially attempt to connect with and AuthMethod of 'none' (with the understanding that this attempt will fail, and the SSH server will advertise which authentication methods it supports), It is recommended to check the AuthMethod, User, and ConnectionId parameters of the on_ssh_user_auth_request event and set this config accordingly.

When SSHServer displays keyboard-interactive prompts, it will first check to see if this config is populated for the current ConnectionId. If it is, the prompts set here will be used instead of those set in the keyboard_interactive_prompts property. Otherwise, the keyboard_interactive_prompts property will function as normal.

KeyRenegotiationThreshold:   Sets the threshold for the SSH Key Renegotiation.

This property allows you to specify the threshold, in the number of bytes, for the SSH Key Renegotiation. The default value for this property is set to 1 GB.

Example (for setting the threshold to 500 MB): SSHComponent.Config("KeyRenegotiationThreshold=524288000")

LogLevel:   Specifies the level of detail that is logged.

This setting controls the level of detail that is logged through the on_log event. Possible values are:

0 (None) No messages are logged.
1 (Info - Default) Informational events such as SSH handshake messages are logged.
2 (Verbose) Detailed data such as individual packet information is logged.
3 (Debug) Debug data including all relevant sent and received bytes are logged.

MaxAuthAttempts:   The maximum authentication attempts allowed before forcing a disconnect.

This setting specifies the maximum amount of authentication attempts that will be allowed before forcibly disconnecting the client.

NegotiatedStrictKex[ConnectionId]:   Returns whether strict key exchange was negotiated to be used.

Returns whether strict key exchange (strict kex) was negotiated during the SSH handshake. This is a per-connection setting accessed by passing the ConnectionId. If strict kex is being used, then this will return "True". If strict kex is not being used, then this will return "False".

component.Config("NegotiatedStrictKex[connId]")

ServerSSHVersionString:   The SSH version string sent to connecting clients.

This setting specifies the version string value that is sent to all connecting clients. This may be set to specify server specific information. The default value is "SSH-2.0-IPWorks SSH Daemon 2022". When setting your own value it must begin with "SSH-2.0-" as this is a standard format that specifies the supported SSH version.

SSHKeepAliveCountMax:   The maximum number of keep alive packets to send without a response.

This setting specifies the maximum number of keep alive packets to send when no response is received. Normally a response to a keep alive packet is received right away. If no response is received the class will continue to send keep alive packets until SSHKeepAliveCountMax is reached. If this is reached the class will assume the connection is broken and disconnect. The default value is 5.

SSHKeepAliveInterval:   The interval between keep alive packets.

This setting specifies the number of seconds between keep alive packets. If set to a positive value the class will send a SSH keep alive packet after KeepAliveInterval seconds of inactivity. This setting only takes effect when there is no activity, if any data is sent or received over the connection it will reset the timer.

The default value is 0 meaning no keep alives will be sent.

Note: The SSHReverseTunnel class uses a default value of 30.

SSHKeyExchangeAlgorithms:   Specifies the supported key exchange algorithms.

This may be used to specify the list of supported key exchange algorithms used during SSH negotiation. The value should contain a comma separated list of algorithms. Supported algorithms are:

  • curve25519-sha256
  • curve25519-sha256@libssh.org
  • diffie-hellman-group1-sha1
  • diffie-hellman-group14-sha1
  • diffie-hellman-group14-sha256
  • diffie-hellman-group16-sha512
  • diffie-hellman-group18-sha512
  • diffie-hellman-group-exchange-sha256
  • diffie-hellman-group-exchange-sha1
  • ecdh-sha2-nistp256
  • ecdh-sha2-nistp384
  • ecdh-sha2-nistp521
  • gss-group14-sha256-toWM5Slw5Ew8Mqkay+al2g==
  • gss-group16-sha512-toWM5Slw5Ew8Mqkay+al2g==
  • gss-nistp256-sha256-toWM5Slw5Ew8Mqkay+al2g==
  • gss-curve25519-sha256-toWM5Slw5Ew8Mqkay+al2g==
  • gss-group14-sha1-toWM5Slw5Ew8Mqkay+al2g==
  • gss-gex-sha1-toWM5Slw5Ew8Mqkay+al2g==
The default value is: curve25519-sha256,curve25519-sha256@libssh.org,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1,gss-group14-sha256-toWM5Slw5Ew8Mqkay+al2g==,gss-group16-sha512-toWM5Slw5Ew8Mqkay+al2g==,gss-nistp256-sha256-toWM5Slw5Ew8Mqkay+al2g==,gss-curve25519-sha256-toWM5Slw5Ew8Mqkay+al2g==,gss-group14-sha1-toWM5Slw5Ew8Mqkay+al2g==,gss-gex-sha1-toWM5Slw5Ew8Mqkay+al2g==.
SSHMacAlgorithms:   Specifies the supported Mac algorithms.

This may be used to specify an alternate list of supported Mac algorithms used during SSH negotiation. This also specifies the order in which the Mac algorithms are preferred. The value should contain a comma separated list of algorithms. Supported algorithms are:

  • hmac-sha1
  • hmac-md5
  • hmac-sha1-96
  • hmac-md5-96
  • hmac-sha2-256
  • hmac-sha2-256-96
  • hmac-sha2-512
  • hmac-sha2-512-96
  • hmac-ripemd160
  • hmac-ripemd160-96
  • hmac-sha2-256-etm@openssh.com
  • hmac-sha2-512-etm@openssh.com
  • umac-64@openssh.com
  • umac-64-etm@openssh.com
  • umac-128@openssh.com
  • umac-128-etm@openssh.com
The default value is hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-md5,hmac-ripemd160,hmac-sha1-96,hmac-md5-96,hmac-sha2-256-96,hmac-sha2-512-96,hmac-ripemd160-96,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,umac-64@openssh.com,umac-64-etm@openssh.com,umac-128@openssh.com,umac-128-etm@openssh.com.
SSHPubKeyAuthSigAlgorithms:   Specifies the allowed signature algorithms used by a client performing public key authentication.

This setting specifies a list of signature algorithms that a client is allowed to use when authenticating to the server using public key authentication. This applies only when public key authentication is performed by the client.

The setting should be a comma separated list of algorithms. When a client connects the server will verify that the client performing public key authentication has used one of the specified signature algorithms. If the client uses a signature algorithm which is not in the list the connection will be rejected.

Possible values are:

  • ssh-rsa
  • rsa-sha2-256
  • rsa-sha2-512
  • ssh-dss
  • ecdsa-sha2-nistp256
  • ecdsa-sha2-nistp384
  • ecdsa-sha2-nistp521
  • ssh-ed25519
  • x509v3-sign-rsa
  • x509v3-sign-dss

The default value in Windows is ssh-rsa,rsa-sha2-256,rsa-sha2-512,x509v3-sign-rsa,ssh-dss,x509v3-sign-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519.

SSHPublicKeyAlgorithms:   Specifies the supported public key algorithms for the server's public key.

This setting specifies the allowed public key algorithms for the server's public key. This list controls only the public key algorithm used when authenticating the server's public key. This list has no bearing on the public key algorithms that can be used by the client when performing public key authentication to the server. The default value is ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,rsa-sha2-256,rsa-sha2-512,ssh-rsa,ssh-dss,x509v3-sign-rsa,x509v3-sign-dss.

SSHVersionPattern:   The pattern used to match the remote host's version string.

This configuration setting specifies the pattern used to accept or deny the remote host's SSH version string. It takes a comma-delimited list of patterns to match. The default value is "*SSH-1.99-*,*SSH-2.0-*" and will accept connections from SSH 1.99 and 2.0 hosts. As an example, the below value would accept connections for SSH 1.99, 2.0, and 2.99 hosts.

*SSH-1.99-*,*SSH-2.0-*,*SSH-2.99-*
UserAuthBanner[ConnectionId]:   A custom user authentication banner.

This setting specifies a custom user authentication banner, which may be sent to give the client more information regarding an authentication attempt. "connectionId" specifies the particular connection to send the message to. This configuration option is only effective when set within the on_ssh_user_auth_request event.

UseStrictKeyExchange:   Specifies how strict key exchange is supported.

This setting controls whether strict key exchange (strict kex) is enabled to mitigate the Terrapin attack. When enabled, the class will indicate support for strict key exchange by automatically including the pseudo-algorithm kex-strict-c-v00@openssh.com for client classes and kex-strict-s-v00@openssh.com for server classes in the list of supported key exchange algorithms.

Since both client and server must implement strict key exchange to effectively mitigate the Terrapin attack, the class provides options to further control the behavior in different scenarios. Possible values for this setting are:

0Disabled. Strict key exchange is not supported in the class.
1 (default)Enabled, but not enforced. This setting enables strict key exchange, but if the remote host does not support strict key exchange the connection is still allowed to continue.
2Enabled, but reject affected algorithms if the remote host does not support strict key exchange. If the remote host supports strict key exchange all algorithms may be used. If the remote host does not support strict key exchange the connection will only continue if the selected encryption and MAC algorithms are not affected by the Terrapin attack.
3Required. If the remote host does not support strict key exchange the connection will fail.

TCPServer Config Settings

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

This configuration setting defines a comma-separated list of host names or IPv4 addresses that may access the class. The wildcard character "*" is supported. The default value is "*" and all connections are accepted.

When a client connects, the client's address is checked against the list defined here. If there is no match, the on_connection_request event fires with an Accept value set to False. If no action is taken within the on_connection_request event, the client will be disconnected.

BindExclusively:   Whether or not the component considers a local port reserved for exclusive use.

If this is True (default), the component will bind to the local port with the ExclusiveAddressUse option set, meaning that nothing else can bind to the same port. Also the component will not be able to bind to local ports that are already in use by some other instance, and attempts to do so will result in failure.

BlockedClients:   A comma-separated list of host names or IP addresses that cannot access the class.

This configuration setting defines a comma-separated list of host names or IPv4 addresses that cannot access the class.The default value is "" and all connections are accepted.

When a client connects, the client's address is checked against the list defined here. If there is a match, the on_connection_request event fires with an Accept value set to False. If no action is taken within the on_connection_request event, the client will not be connected.

ConnectionUID:   The unique connectionId for a connection.

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

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

DefaultConnectionTimeout:   The inactivity timeout applied to the SSL handshake.

This configuration setting specifies the inactivity (in seconds) to apply to incoming Secure Sockets Layer (SSL) connections. When set to a positive value, if the other end is unresponsive for the specified number of seconds, the connection will timeout. This is not applicable to the entire handshake. It is applicable only to the inactivity of the connecting client during the handshake if a response is expected and none is received within the timeout window. The default value is 0, and no connection-specific timeout is applied.

Note: This is applicable only to incoming SSL connections. This should be set only if there is a specific reason to do so.

InBufferSize:   The size in bytes of the incoming queue of the socket.

This is the size of an internal queue in the Transmission Control Protocol (TCP)/IP stack. You can increase or decrease its size depending on the amount of data that you will be receiving. Increasing the value of the InBufferSize setting can provide significant improvements in performance in some cases.

Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the class is activated, the InBufferSize reverts to its defined size. The same thing will happen if you attempt to make it too large or too small.

InBufferSize is shared among incoming connections. When the property is set, the corresponding value is set for incoming connections as they are accepted. Existing connections are not modified.

KeepAliveInterval:   The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.

A TCP keep-alive packet will be sent after a period of inactivity, as defined by KeepAliveTime. If no acknowledgment is received from the remote host, the keep-alive packet will be sent again. This setting specifies the interval at which the successive keep-alive packets are sent in milliseconds. If this value is not specified here, the system default is 1 second. This setting is applicable to all connections.

Note: This value is not applicable in macOS.

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

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

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

KeepAliveTime:   The inactivity time in milliseconds before a TCP keep-alive packet is sent.

By default, the operating system will determine the time a connection is idle before a TCP keep-alive packet is sent. If this value is not specified here, the system default is 2 hours. In many cases, a shorter interval is more useful. Set this value to the desired interval in milliseconds. This setting is applicable to all connections.

MaxConnections:   The maximum number of connections available.

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

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

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

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

The default value is 50 (milliseconds).

OutBufferSize:   The size in bytes of the outgoing queue of the socket.

This is the size of an internal queue in the TCP/IP stack. You can increase or decrease its size depending on the amount of data that you will be sending. Increasing the value of the OutBufferSize setting can provide significant improvements in performance in some cases.

Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the class is activated the OutBufferSize reverts to its defined size. The same thing will happen if you attempt to make it too large or too small.

OutBufferSize is shared among incoming connections. When the property is set, the corresponding value is set for incoming connections as they are accepted. Existing connections are not modified.

TcpNoDelay:   Whether or not to delay when sending packets.

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

By default, this config is set to false.

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

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

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

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

UseIPv6:   Whether to use IPv6.

When set to 0 (default), the class will use IPv4 exclusively. When set to 1, the class will use IPv6 exclusively. When set to 2, the class will listen for both IPv4 and IPv6 connections. If IPv6 is not available on the system, only IPv4 will be used. The default value is 0. Possible values are as follows:

0 IPv4 Only
1 IPv6 Only
2 IPv6 and IPv4
UseWindowsMessages:   Whether to use the WSAAsyncSelect I/O model.

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

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

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

Base Config Settings

BuildInfo:   Information about the product's build.

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

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

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

The following is a list of valid code page identifiers:

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

LicenseInfo:   Information about the current license.

When queried, this setting will return a string containing information about the license this instance of a class is using. It will return the following information:

  • Product: The product the license is for.
  • Product Key: The key the license was generated from.
  • License Source: Where the license was found (e.g., RuntimeLicense, License File).
  • License Type: The type of license installed (e.g., Royalty Free, Single Server).
  • Last Valid Build: The last valid build number for which the license will work.
MaskSensitive:   Whether sensitive data is masked in log messages.

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

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

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

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

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

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

UseFIPSCompliantAPI:   Tells the class whether or not to use FIPS certified APIs.

When set to True, the class will utilize the underlying operating system's certified APIs. Java editions, regardless of OS, utilize Bouncy Castle FIPS, while all the other Windows editions make use of Microsoft security libraries.

FIPS mode can be enabled by setting the UseFIPSCompliantAPI configuration setting to True. This is a static setting which applies to all instances of all classes of the toolkit within the process. It is recommended to enable or disable this setting once before the component has been used to establish a connection. Enabling FIPS while an instance of the component is active and connected may result in unexpected behavior.

For more details please see the FIPS 140-2 Compliance article.

Note: This setting is only applicable on Windows.

Note: Enabling FIPS-compliance requires a special license; please contact sales@nsoftware.com for details.

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 section.

SSHServer Errors

SSHServer Errors

1201   Could not forward connection. A detailed message follows.
1202   Could not forward connection/channel data. A detailed message follows.
1300   Could not authenticate client.
1301   No server certificate was specified or no private key found.

TCPServer Errors

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

TCP/IP Errors

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