SSHTunnel Control

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The SSHTunnel control can be used to tunnel data through an SSH server to a remote location.

Syntax

SSHTunnel

Remarks

The SSHTunnel control implements a daemon that accepts connections and tunnels the data from those connections over a Secure Shell (SSH) connection to a remote location.

First, set SSHHost to the server you wish to use to tunnel the data. SSHUser, SSHPassword and the SSHCert* properties can be used to authenticate the tunneling connection.

Second, set SSHForwardHost to the hostname or IP address of the destination machine, and SSHForwardPort to the port to which you wish to send data. Finally, call StartListening. The control will listen for connections on the interface identified by LocalHost and LocalPort.

When a client attempts to connect to the control, the control will fire a ConnectionRequest event that can be used to accept or reject the connection. If the connection is accepted, the control will attempt to logon to the SSHHost, and will tell the server to connect remotely to another machine. Once this process is complete, the tunnel will be established and data can be securely transmitted from end to end.

Example: Connecting Between Networks

A client which exists in Network A wishes to connect to a resource that exists in Network B. Both networks are secured by a firewall, making it difficult to freely connect to resources within the other network. However, Network B contains an SSH server which supports tunneling. An SSHTunnel control set up with Network A can be used to access any resource in Network B.

The SSHHost and SSHPort properties must be set to the hostname and port exposed by Network B's firewall. SSHForwardHost and SSHForwardPort are then set to the value of the resource within Network B to which the client in Network A wishes to connect. Any client in Network A can then connect to the SSHTunnel instance's LocalHost and LocalPort.

As clients within Network A connect to the SSHTunnel, the control will forward the connections, secured by SSH, through the network firewalls to the SSH server in Network B. The SSH server will then connect to the resource within Network B and forward all data received from the SSHTunnel instance to that resource. All data received from the resource will then be forwarded back to the original client in Network A.

Dynamic Forwarding

Dynamic forwarding is a feature provided by SSH that leverages the SOCKS protocol. With dynamic forwarding, the SSHTunnel component acts as a SOCKS proxy, and all relevant traffic is relayed through the SSH connection to the destination defined by the client that made the request. The SSHTunnel component supports dynamic forwarding automatically when SSHForwardHost and SSHForwardPort are not specified (the forwarding host is determined dynamically).

The client making requests through SSHTunnel must be configured to use a SOCKS proxy, where the proxy port is the same as the LocalPort property. In IPWorks components a SOCKS proxy can be enabled like so:

// Enable the SOCKS proxy for IPWorks' HTTP component http.Firewall.FirewallType = nsoftware.IPWorks.FirewallTypes.fwSOCKS5; http.Firewall.Port = 1234; //The port set in the SSHTunnel LocalPort property http.Firewall.Host = "localhost"; //The hostname or IP address where SSHTunnel is listening

Note: SSHTunnel can support either dynamic forwarding (SSHForwardHost and SSHForwardPort are not set), or standard forwarding (SSHForwardHost and SSHForwardPort are set). It cannot support both modes at the same time. As a result it is expected that clients connecting to the SSHTunnel component are configured in a way that matches the configuration of the SSHTunnel component (dynamic or standard forwarding). For example, if SSHTunnel has the SSHForwardHost and SSHForwardPort properties set, then the client must NOT treat SSHTunnel as a SOCKS proxy. If the SSHTunnel does not have the aforementioned properties set, then the client MUST treat SSHTunnel as a SOCKS proxy.

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

Property List


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

ConnectedThis shows whether the control is connected.
ConnectionBacklogThis property includes the maximum number of pending connections maintained by the Transmission Control Protocol (TCP)/IP subsystem.
ClientCountThe number of records in the Client arrays.
ClientAcceptDataSetting this property to false temporarily disables data reception (and the DataIn event) for the connection.
ClientBytesSentThis property shows how many bytes were sent after the last assignment to DataToSend .
ClientConnectedThis property is used to disconnect individual connections or to show their status.
ClientConnectionIdThis property contains an identifier generated by the control to identify each connection.
ClientDataToSendThis property contains a string of data to be sent to the remote host.
ClientEOLThe EOL property is used to define boundaries in the input stream using the value of the property.
ClientIdleTimeoutThis property contains the idle timeout for this connection.
ClientLocalAddressThis property shows the IP address of the interface through which the connection is passing.
ClientReadyToSendThis indicates whether the control is ready to send data.
ClientRecordLengthIf set to a positive value, this setting defines the length of the data records to be received.
ClientRemoteHostThis property shows the IP address of the remote host through which the connection is coming.
ClientRemotePortThis property shows the Transmission Control Protocol (TCP) port on the remote host through which the connection is coming.
ClientSingleLineModeThis property shows the special mode for line-oriented protocols.
ClientTimeoutThis property specifies a timeout for the control.
ClientUserDataThe UserData property holds connection-specific user-specified data.
DefaultEOLThis property includes a default end-of-line (EOL) value to be used by incoming connections.
DefaultSingleLineModeThis property tells the control whether or not to treat new connections as line oriented.
DefaultTimeoutThis property includes an initial timeout value to be used by incoming connections.
FirewallAutoDetectThis property tells the control whether or not to automatically detect and use firewall system settings, if available.
FirewallTypeThis property determines the type of firewall to connect through.
FirewallHostThis property contains the name or IP address of firewall (optional).
FirewallPasswordThis property contains a password if authentication is to be used when connecting through the firewall.
FirewallPortThis property contains the transmission control protocol (TCP) port for the firewall Host .
FirewallUserThis property contains a user name if authentication is to be used connecting through a firewall.
KeepAliveWhen True, KEEPALIVE packets are enabled (for long connections).
LingerWhen set to True, connections are terminated gracefully.
ListeningIf set to True, the control accepts incoming connections on LocalPort.
LocalHostThe name of the local host or user-assigned IP interface through which connections are initiated or accepted.
LocalPortThe TCP port in the local host where the control binds.
SSHAcceptServerHostKeyEncodedThis is the certificate (PEM/base64 encoded).
SSHAuthModeThe authentication method to be used the control when calling SSHLogon .
SSHCertEncodedThis is the certificate (PEM/base64 encoded).
SSHCertStoreThis is the name of the certificate store for the client certificate.
SSHCertStorePasswordIf the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.
SSHCertStoreTypeThis is the type of certificate store for this certificate.
SSHCertSubjectThis is the subject of the certificate used for client authentication.
SSHCompressionAlgorithmsA comma-separated list containing all allowable compression algorithms.
SSHEncryptionAlgorithmsA comma-separated list containing all allowable encryption algorithms.
SSHForwardHostThe address of the remote host. Domain names are resolved to IP addresses.
SSHForwardPortThe TCP port in the remote host.
SSHHostThe address of the SSH host.
SSHPasswordThe password for SSH password-based authentication.
SSHPortThe port on the SSH server where the SSH service is running; by default, 22.
SSHUserThe username for SSH authentication.

Method List


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

ConfigSets or retrieves a configuration setting.
ConnectConnects to the SSH host without logging in.
DecodePacketDecodes a hex-encoded SSH packet.
DisconnectThis method disconnects the specified client.
DoEventsProcesses events from the internal message queue.
EncodePacketHex encodes an SSH packet.
GetSSHParamUsed to read a field from an SSH packet's payload.
GetSSHParamBytesUsed to read a field from an SSH packet's payload.
ResetReset the control.
SetSSHParamUsed to write a field to the end of a payload.
ShutdownThis method shuts down the server.
StartListeningThis method starts listening for incoming connections.
StopListeningThis method stops listening for new connections.

Event List


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

ConnectedThis event is fired immediately after a connection completes (or fails).
ConnectionRequestThis event is fired when a request for connection comes from a remote host.
DataInThis event is fired when data come in.
DisconnectedFired when a connection is closed.
ErrorInformation about errors during data delivery.
LogFires once for each log message.
ReconnectAttemptFires when attempting to reconnect.
SSHCustomAuthFired when the control is doing custom authentication.
SSHKeyboardInteractiveFired when the control receives a request for user input from the server.
SSHServerAuthenticationFired after the server presents its public key to the client.
SSHStatusShows the progress of the secure connection.

Config Settings


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

AutoReconnectWhether to automatically reconnect.
MaxRetryCountThe maximum number of retries when reconnecting.
RetryIntervalThe interval in seconds between reconnect attempts.
ShutdownChannelOnEOFWhether the client will shutdown the channel after receiving an EOF packet from the remote host.
ChannelDataEOL[ChannelId]Used to break the incoming data stream into chunks.
ChannelDataEOLFound[ChannelId]Determines if ChannelDataEOL was found.
ClientSSHVersionStringThe SSH version string used by the control.
EnablePageantAuthWhether to use a key stored in Pageant to perform client authentication.
KerberosDelegationIf true, asks for credentials with delegation enabled during authentication.
KerberosRealmThe fully qualified domain name of the Kerberos Realm to use for GSSAPI authentication.
KerberosSPNThe Kerberos Service Principal Name of the SSH host.
KeyRenegotiationThresholdSets the threshold for the SSH Key Renegotiation.
LogLevelSpecifies the level of detail that is logged.
MaxChannelDataLength[ChannelId]The maximum amount of data to accumulate when no ChannelDataEOL is found.
MaxPacketSizeThe maximum packet size of the channel, in bytes.
MaxWindowSizeThe maximum window size allowed for the channel, in bytes.
PasswordPromptThe text of the password prompt used in keyboard-interactive authentication.
PreferredDHGroupBitsThe size (in bits) of the preferred modulus (p) to request from the server.
RecordLengthThe length of received data records.
ServerSSHVersionStringThe remote host's SSH version string.
SignedSSHCertThe CA signed client public key used when authenticating.
SSHAcceptAnyServerHostKeyIf set the control will accept any key presented by the server.
SSHAcceptServerCAKeyThe CA public key that signed the server's host key.
SSHAcceptServerHostKeyFingerPrintThe fingerprint of the server key to accept.
SSHFingerprintHashAlgorithmThe algorithm used to calculate the fingerprint.
SSHFingerprintMD5The server hostkey's MD5 fingerprint.
SSHFingerprintSHA1The server hostkey's SHA1 fingerprint.
SSHFingerprintSHA256The server hostkey's SHA256 fingerprint.
SSHKeepAliveCountMaxThe maximum number of keep alive packets to send without a response.
SSHKeepAliveIntervalThe interval between keep alive packets.
SSHKeyExchangeAlgorithmsSpecifies the supported key exchange algorithms.
SSHKeyRenegotiateCauses the control to renegotiate the SSH keys.
SSHMacAlgorithmsSpecifies the supported Mac algorithms.
SSHPubKeyAuthSigAlgorithmsSpecifies the enabled signature algorithms that may be used when attempting 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.
TryAllAvailableAuthMethodsIf set to true, the control will try all available authentication methods.
UseStrictKeyExchangeSpecifies how strict key exchange is supported.
WaitForChannelCloseWhether to wait for channels to be closed before disconnected.
WaitForServerDisconnectWhether to wait for the server to close the connection.
ConnectionTimeoutSets a separate timeout value for establishing a connection.
FirewallAutoDetectTells the control whether or not to automatically detect and use firewall system settings, if available.
FirewallHostName or IP address of firewall (optional).
FirewallPasswordPassword to be used if authentication is to be used when connecting through the firewall.
FirewallPortThe TCP port for the FirewallHost;.
FirewallTypeDetermines the type of firewall to connect through.
FirewallUserA user name if authentication is to be used connecting through a firewall.
KeepAliveIntervalThe retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.
KeepAliveTimeThe inactivity time in milliseconds before a TCP keep-alive packet is sent.
LingerWhen set to True, connections are terminated gracefully.
LingerTimeTime in seconds to have the connection linger.
LocalHostThe name of the local host through which connections are initiated or accepted.
LocalPortThe port in the local host where the control binds.
MaxLineLengthThe maximum amount of data to accumulate when no EOL is found.
MaxTransferRateThe transfer rate limit in bytes per second.
ProxyExceptionsListA semicolon separated list of hosts and IPs to bypass when using a proxy.
TCPKeepAliveDetermines whether or not the keep alive socket option is enabled.
TcpNoDelayWhether or not to delay when sending packets.
UseIPv6Whether to use IPv6.
AbsoluteTimeoutDetermines whether timeouts are inactivity timeouts or absolute timeouts.
FirewallDataUsed to send extra data to the firewall.
InBufferSizeThe size in bytes of the incoming queue of the socket.
OutBufferSizeThe size in bytes of the outgoing queue of the socket.
AllowedClientsA comma-separated list of host names or IP addresses that can access the control.
BindExclusivelyWhether or not the control considers a local port reserved for exclusive use.
BlockedClientsA comma-separated list of host names or IP addresses that cannot access the control.
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.
KeepAliveTimeThe inactivity time in milliseconds before a TCP keep-alive packet is sent.
MaxConnectionsThe maximum number of connections available.
OutBufferSizeThe size in bytes of the outgoing queue of the socket.
TcpNoDelayWhether or not to delay when sending packets.
UseIPv6Whether to use IPv6.
CodePageThe system code page used for Unicode to Multibyte translations.
MaskSensitiveWhether sensitive data is masked in log messages.
UseInternalSecurityAPITells the control whether or not to use the system security libraries or an internal implementation.

Connected Property (SSHTunnel Control)

This shows whether the control is connected.

Syntax

sshtunnelcontrol.Connected[=boolean]

Default Value

False

Remarks

This property is used to determine whether or not the control is connected to the remote host.

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

This property is not available at design time.

Data Type

Boolean

ConnectionBacklog Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.ConnectionBacklog[=integer]

Default Value

5

Remarks

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

This property is not available at design time.

Data Type

Integer

ClientCount Property (SSHTunnel Control)

The number of records in the Client arrays.

Syntax

sshtunnelcontrol.ClientCount

Default Value

0

Remarks

This property controls the size of the following arrays:

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

This property is read-only and not available at design time.

Data Type

Integer

ClientAcceptData Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.ClientAcceptData(ClientId)[=boolean]

Default Value

True

Remarks

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

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

The ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

This property is not available at design time.

Data Type

Boolean

ClientBytesSent Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.ClientBytesSent(ClientId)

Default Value

0

Remarks

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

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

The ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

This property is read-only and not available at design time.

Data Type

Integer

ClientConnected Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.ClientConnected(ClientId)[=boolean]

Default Value

False

Remarks

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

The ClientConnected property may be set to to close the connection.

ClientConnected 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 ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

This property is not available at design time.

Data Type

Boolean

ClientConnectionId Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.ClientConnectionId(ClientId)

Default Value

""

Remarks

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

The ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

This property is read-only and not available at design time.

Data Type

String

ClientDataToSend Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.ClientDataToSend(ClientId)[=string]

Default Value

""

Remarks

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

Assigning a string to the ClientDataToSend makes the control send the string to the remote host. The Send method provides similar functionality.

When ClientTimeout is set to 0, the control will behave asynchronously. If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, the operation fails with error 25036: "[10035] Operation would block" (WSAEWOULDBLOCK). You can trap this error, and then try to send the data again. . The BytesSent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the ReadyToSend event before attempting to send data again.

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

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

The ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

To read or write binary data to the property, a Variant (Byte Array) version is provided in .ClientDataToSendB.

This property is write-only and not available at design time.

Data Type

Binary String

ClientEOL Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.ClientEOL(ClientId)[=string]

Default Value

""

Remarks

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

The ClientEOL property is especially useful with ASCII files. By setting it to CRLF (Chr$(13) & Chr$(10)) , the incoming ASCII text stream can be split into lines. In this case, one event is fired for each line received (as well as in packet boundaries). The CRLF (Chr$(13) & Chr$(10)) . bytes are discarded.

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

The ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

To read or write binary data to the property, a Variant (Byte Array) version is provided in .ClientEOLB.

This property is not available at design time.

Data Type

Binary String

ClientIdleTimeout Property (SSHTunnel Control)

This property contains the idle timeout for this connection.

Syntax

sshtunnelcontrol.ClientIdleTimeout(ClientId)[=integer]

Default Value

0

Remarks

This property contains the idle timeout for this connection. This property is similar to DefaultIdleTimeout but may be set on a per-connection basis to override DefaultIdleTimeout. This property specifies the idle timeout (in seconds) for the connected client. When set to a positive value, the control will disconnect idle clients after the specified timeout.

This applies only to clients that have not sent to received data within the specified number of seconds.

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

Note: DoEvents must be called for the control to check existing connections.

The ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

This property is not available at design time.

Data Type

Integer

ClientLocalAddress Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.ClientLocalAddress(ClientId)

Default Value

""

Remarks

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

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

The ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

This property is read-only and not available at design time.

Data Type

String

ClientReadyToSend Property (SSHTunnel Control)

This indicates whether the control is ready to send data.

Syntax

sshtunnelcontrol.ClientReadyToSend(ClientId)

Default Value

False

Remarks

This indicates whether the control is ready to send data.

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

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

The ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

This property is read-only and not available at design time.

Data Type

Boolean

ClientRecordLength Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.ClientRecordLength(ClientId)[=integer]

Default Value

0

Remarks

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

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

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

The ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

This property is not available at design time.

Data Type

Integer

ClientRemoteHost Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.ClientRemoteHost(ClientId)

Default Value

""

Remarks

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

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

If the control 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 ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

This property is read-only and not available at design time.

Data Type

String

ClientRemotePort Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.ClientRemotePort(ClientId)

Default Value

0

Remarks

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

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

The ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

This property is read-only and not available at design time.

Data Type

Integer

ClientSingleLineMode Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.ClientSingleLineMode(ClientId)[=boolean]

Default Value

False

Remarks

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

The ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

This property is not available at design time.

Data Type

Boolean

ClientTimeout Property (SSHTunnel Control)

This property specifies a timeout for the control.

Syntax

sshtunnelcontrol.ClientTimeout(ClientId)[=integer]

Default Value

0

Remarks

This property specifies a timeout for the control.

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

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

The control 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 control 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 ClientTimeout property is 0 (asynchronous operation).

The ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

This property is not available at design time.

Data Type

Integer

ClientUserData Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.ClientUserData(ClientId)[=string]

Default Value

""

Remarks

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

User-specified data may be set or retrieved at any point while the connection is valid. This provides a simple way to associate arbitrary data with a specific connection.

The ClientId parameter specifies the index of the item in the array. The size of the array is controlled by the ClientCount property.

To read or write binary data to the property, a Variant (Byte Array) version is provided in .ClientUserDataB.

This property is not available at design time.

Data Type

Binary String

DefaultEOL Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.DefaultEOL[=string]

Default Value

""

Remarks

This property contains a default end-of-line (EOL) value to be used by incoming connections. Once the control accepts and establishes an inbound connection, it will set that connection's EOL to the value in this property. By default, this value is empty (""), meaning that data will be fired as it is received.

To read or write binary data to the property, a Variant (Byte Array) version is provided in .DefaultEOLB.

Data Type

Binary String

DefaultSingleLineMode Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.DefaultSingleLineMode[=boolean]

Default Value

False

Remarks

This property instructs the component whether or not to treat newly established connections as line-oriented protocols. If this value is True, newly accepted connections will read the incoming data stream as lines separated by a carriage return line feed (CRLF), carriage return (CR), or line feed (LF) and will ignore the end of lines (EOLs).

Data Type

Boolean

DefaultTimeout Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.DefaultTimeout[=integer]

Default Value

0

Remarks

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

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

Data Type

Integer

FirewallAutoDetect Property (SSHTunnel Control)

This property tells the control whether or not to automatically detect and use firewall system settings, if available.

Syntax

sshtunnelcontrol.FirewallAutoDetect[=boolean]

Default Value

False

Remarks

This property tells the control whether or not to automatically detect and use firewall system settings, if available.

Data Type

Boolean

FirewallType Property (SSHTunnel Control)

This property determines the type of firewall to connect through.

Syntax

sshtunnelcontrol.FirewallType[=integer]

Possible Values

fwNone(0), 
fwTunnel(1), 
fwSOCKS4(2), 
fwSOCKS5(3), 
fwSOCKS4A(10)

Default Value

0

Remarks

This property determines the type of firewall to connect through. The applicable values are as follows:

fwNone (0)No firewall (default setting).
fwTunnel (1)Connect through a tunneling proxy. FirewallPort is set to 80.
fwSOCKS4 (2)Connect through a SOCKS4 Proxy. FirewallPort is set to 1080.
fwSOCKS5 (3)Connect through a SOCKS5 Proxy. FirewallPort is set to 1080.
fwSOCKS4A (10)Connect through a SOCKS4A Proxy. FirewallPort is set to 1080.

Data Type

Integer

FirewallHost Property (SSHTunnel Control)

This property contains the name or IP address of firewall (optional).

Syntax

sshtunnelcontrol.FirewallHost[=string]

Default Value

""

Remarks

This property contains the name or IP address of firewall (optional). If a FirewallHost is given, the requested connections will be authenticated through the specified firewall when connecting.

If this property is set to a Domain Name, a DNS request is initiated. Upon successful termination of the request, this property is set to the corresponding address. If the search is not successful, the control fails with an error.

Data Type

String

FirewallPassword Property (SSHTunnel Control)

This property contains a password if authentication is to be used when connecting through the firewall.

Syntax

sshtunnelcontrol.FirewallPassword[=string]

Default Value

""

Remarks

This property contains a password if authentication is to be used when connecting through the firewall. If FirewallHost is specified, the FirewallUser and FirewallPassword properties are used to connect and authenticate to the given firewall. If the authentication fails, the control fails with an error.

Data Type

String

FirewallPort Property (SSHTunnel Control)

This property contains the transmission control protocol (TCP) port for the firewall Host .

Syntax

sshtunnelcontrol.FirewallPort[=integer]

Default Value

0

Remarks

This property contains the transmission control protocol (TCP) port for the firewall FirewallHost. See the description of the FirewallHost property for details.

Note: This property is set automatically when FirewallType is set to a valid value. See the description of the FirewallType property for details.

Data Type

Integer

FirewallUser Property (SSHTunnel Control)

This property contains a user name if authentication is to be used connecting through a firewall.

Syntax

sshtunnelcontrol.FirewallUser[=string]

Default Value

""

Remarks

This property contains a user name if authentication is to be used connecting through a firewall. If the FirewallHost is specified, this property and FirewallPassword properties are used to connect and authenticate to the given Firewall. If the authentication fails, the control fails with an error.

Data Type

String

KeepAlive Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.KeepAlive[=boolean]

Default Value

False

Remarks

This property enables the SO_KEEPALIVE option on the incoming connections. This option prevents long connections from timing out in case of inactivity.

Note: System Transmission Control Protocol (TCP)/IP stack implementations are not required to support SO_KEEPALIVE.

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

Data Type

Boolean

Linger Property (SSHTunnel Control)

When set to True, connections are terminated gracefully.

Syntax

sshtunnelcontrol.Linger[=boolean]

Default Value

True

Remarks

This property controls how a connection is closed. The default is True. In this case, the connection is closed only after all the data are sent. Setting it to False forces an abrupt (hard) disconnection. Any data that were in the sending queue may be lost.

The default behavior (which is also the default mode for stream sockets) might result in an indefinite delay in closing the connection. Although the control returns control immediately, the system might indefinitely hold system resources until all pending data are sent (even after your application closes). This means that valuable system resources might be wasted.

Setting this property to False forces an immediate disconnection. If you know that the other side has received all the data you have sent (e.g., by a client acknowledgment), then setting this property to False might be the appropriate course of action.

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

Data Type

Boolean

Listening Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.Listening[=boolean]

Default Value

False

Remarks

This property indicates whether the control is listening for connections on the port specified by the LocalPort property.

Note: Use the StartListening and StopListening methods to control whether the control is listening.

This property is not available at design time.

Data Type

Boolean

LocalHost Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.LocalHost[=string]

Default Value

""

Remarks

The LocalHost 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 control initiate connections (or accept in the case of server controls) only through that interface.

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

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

Data Type

String

LocalPort Property (SSHTunnel Control)

The TCP port in the local host where the control binds.

Syntax

sshtunnelcontrol.LocalPort[=integer]

Default Value

0

Remarks

This property must be set before the control can start listening. If its value is 0, then the TCP/IP subsystem picks a port number at random. The port number can be found by checking the value of this property after the control is listening (i.e., after successfully assigning True to the Listening property).

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

This property must be set before a connection is attempted. It instructs the control to bind to a specific port (or communication endpoint) in the local machine.

Setting this property to 0 (default) enables the system to choose an open port at random. The chosen port will be returned by the LocalPort property after the connection is established.

LocalPort cannot be changed once a connection is made. Any attempt to set this property when a connection is active will generate an error.

This property is useful when trying to connect to services that require a trusted port in the client side.

Data Type

Integer

SSHAcceptServerHostKeyEncoded Property (SSHTunnel Control)

This is the certificate (PEM/base64 encoded).

Syntax

sshtunnelcontrol.SSHAcceptServerHostKeyEncoded[=string]

Default Value

""

Remarks

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

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

To read or write binary data to the property, a Variant (Byte Array) version is provided in .SSHAcceptServerHostKeyEncodedB.

This property is not available at design time.

Data Type

Binary String

SSHAuthMode Property (SSHTunnel Control)

The authentication method to be used the control when calling SSHLogon .

Syntax

sshtunnelcontrol.SSHAuthMode[=integer]

Possible Values

amNone(0), 
amMultiFactor(1), 
amPassword(2), 
amPublicKey(3), 
amKeyboardInteractive(4), 
amGSSAPIWithMic(5), 
amCustom(6), 
amGSSAPIKeyex(7)

Default Value

2

Remarks

The SSH Authentication specification (RFC 4252) specifies multiple methods by which a user can be authenticated by an SSH server. When a call is made to SSHLogon, the control will connect to the SSH server and establish the security layer. After the connection has been secured, the client will send an authentication request to the SSHHost containing the SSHUser. The server will respond containing a list of methods by which that user may be authenticated.

The control will attempt to authenticate the user by one of those methods based on the value of SSHAuthMode and other property values supplied by the user. Currently, the control supports the following authentication methods:

amNone (0)No authentication will be performed. The current SSHUser value is ignored, and the connection will be logged in as anonymous.
amMultiFactor (1)This allows the control to attempt a multi-step authentication process. The control will send authentication data to the server based on the list of methods allowed for the current user and the authentication property values supplied. The control will continue to send authentication data until the server acknowledges authentication success. If the server rejects an authentication step, the control fails with an error.
amPassword (2)The control will use the values of SSHUser and SSHPassword to authenticate the user.
amPublicKey (3)The control will use the values of SSHUser and the SSHCert* properties to authenticate the user. the SSHCert* properties must have a private key available for this authentication method to succeed.
amKeyboardInteractive (4)At the time of authentication, the control will fire the SSHKeyboardInteractive event containing instructions on how to complete the authentication step. (NOTE: amKeyboardInteractive is not supported in SSHTunnel).
amGSSAPIWithMic (5)This allows the control to attempt Kerberos authentication using the GSSAPI-WITH-MIC scheme. The client will try Kerberos authentication using the value of SSHUser (single sign-on), or if SSHPassword is specified as well, it will try Kerberos authentication with alternate credentials. This is currently supported only on Windows, unless using the Java edition, which also provides support for Linux and macOS.
amCustom (6)This allows the control caller to take over the authentication process completely. When amCustom is set, the control will fire the SSHCustomAuth event as necessary to complete the authentication process.
amGSSAPIKeyex (7)This allows the control to attempt Kerberos authentication using the GSSAPIKeyex scheme. The client will try Kerberos authentication using the value of SSHUser (single sign-on), or if SSHPassword is specified as well, it will try Kerberos authentication with alternate credentials. This is currently supported only on Windows, unless using the Java edition, which also provides support for Linux and macOS.

Example (User/Password Auth): Control.SSHAuthMode = SftpSSHAuthModes.amPassword Control.SSHUser = "username" Control.SSHPassword = "password" Control.SSHLogon("server", 22) Example (Public Key Auth): Control.SSHAuthMode = SftpSSHAuthModes.amPublicKey Control.SSHUser = "username" Control.SSHCertStoreType = SSHCertStoreTypes.cstPFXFile; Control.SSHCertStore = "cert.pfx"; Control.SSHCertStorePassword = "certpassword"; Control.SSHCertSubject = "*"; Control.SSHLogon("server", 22)

Data Type

Integer

SSHCertEncoded Property (SSHTunnel Control)

This is the certificate (PEM/base64 encoded).

Syntax

sshtunnelcontrol.SSHCertEncoded[=string]

Default Value

""

Remarks

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

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

To read or write binary data to the property, a Variant (Byte Array) version is provided in .SSHCertEncodedB.

This property is not available at design time.

Data Type

Binary String

SSHCertStore Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.SSHCertStore[=string]

Default Value

"MY"

Remarks

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

The SSHCertStoreType property denotes the type of the certificate store specified by SSHCertStore. If the store is password protected, specify the password in SSHCertStorePassword.

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

Designations of certificate stores are platform-dependent.

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

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

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

To read or write binary data to the property, a Variant (Byte Array) version is provided in .SSHCertStoreB.

Data Type

Binary String

SSHCertStorePassword Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.SSHCertStorePassword[=string]

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.

Data Type

String

SSHCertStoreType Property (SSHTunnel Control)

This is the type of certificate store for this certificate.

Syntax

sshtunnelcontrol.SSHCertStoreType[=integer]

Possible Values

cstUser(0), 
cstMachine(1), 
cstPFXFile(2), 
cstPFXBlob(3), 
cstJKSFile(4), 
cstJKSBlob(5), 
cstPEMKeyFile(6), 
cstPEMKeyBlob(7), 
cstPublicKeyFile(8), 
cstPublicKeyBlob(9), 
cstSSHPublicKeyBlob(10), 
cstP7BFile(11), 
cstP7BBlob(12), 
cstSSHPublicKeyFile(13), 
cstPPKFile(14), 
cstPPKBlob(15), 
cstXMLFile(16), 
cstXMLBlob(17), 
cstJWKFile(18), 
cstJWKBlob(19), 
cstSecurityKey(20), 
cstBCFKSFile(21), 
cstBCFKSBlob(22), 
cstPKCS11(23), 
cstAuto(99)

Default Value

0

Remarks

This is the type of certificate store for this certificate.

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

0 (cstUser - default)For Windows, this specifies that the certificate store is a certificate store owned by the current user. Note: this store type is not available in Java.
1 (cstMachine)For Windows, this specifies that the certificate store is a machine store. Note: this store type is not available in Java.
2 (cstPFXFile)The certificate store is the name of a PFX (PKCS12) file containing certificates.
3 (cstPFXBlob)The certificate store is a string (binary or base64-encoded) representing a certificate store in PFX (PKCS12) format.
4 (cstJKSFile)The certificate store is the name of a Java Key Store (JKS) file containing certificates. Note: this store type is only available in Java.
5 (cstJKSBlob)The certificate store is a string (binary or base64-encoded) representing a certificate store in Java Key Store (JKS) format. Note: this store type is only available in Java.
6 (cstPEMKeyFile)The certificate store is the name of a PEM-encoded file that contains a private key and an optional certificate.
7 (cstPEMKeyBlob)The certificate store is a string (binary or base64-encoded) that contains a private key and an optional certificate.
8 (cstPublicKeyFile)The certificate store is the name of a file that contains a PEM- or DER-encoded public key certificate.
9 (cstPublicKeyBlob)The certificate store is a string (binary or base64-encoded) that contains a PEM- or DER-encoded public key certificate.
10 (cstSSHPublicKeyBlob)The certificate store is a string (binary or base64-encoded) that contains an SSH-style public key.
11 (cstP7BFile)The certificate store is the name of a PKCS7 file containing certificates.
12 (cstP7BBlob)The certificate store is a string (binary) representing a certificate store in PKCS7 format.
13 (cstSSHPublicKeyFile)The certificate store is the name of a file that contains an SSH-style public key.
14 (cstPPKFile)The certificate store is the name of a file that contains a PPK (PuTTY Private Key).
15 (cstPPKBlob)The certificate store is a string (binary) that contains a PPK (PuTTY Private Key).
16 (cstXMLFile)The certificate store is the name of a file that contains a certificate in XML format.
17 (cstXMLBlob)The certificate store is a string that contains a certificate in XML format.
18 (cstJWKFile)The certificate store is the name of a file that contains a JWK (JSON Web Key).
19 (cstJWKBlob)The certificate store is a string that contains a JWK (JSON Web Key).
21 (cstBCFKSFile)The certificate store is the name of a file that contains a BCFKS (Bouncy Castle FIPS Key Store). Note: this store type is only available in Java and .NET.
22 (cstBCFKSBlob)The certificate store is a string (binary or base64-encoded) representing a certificate store in BCFKS (Bouncy Castle FIPS Key Store) format. Note: this store type is only available in Java and .NET.
23 (cstPKCS11)The certificate is present on a physical security key accessible via a PKCS11 interface.

To use a security key the necessary data must first be collected using the CertMgr control. The ListStoreCertificates method may be called after setting CertStoreType to cstPKCS11, CertStorePassword to the PIN, and CertStore to the full path of the PKCS11 dll. The certificate information returned in the CertList event's CertEncoded parameter may be saved for later use.

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

Data Type

Integer

SSHCertSubject Property (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.SSHCertSubject[=string]

Default Value

""

Remarks

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

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

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

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

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

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

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

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

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

Data Type

String

SSHCompressionAlgorithms Property (SSHTunnel Control)

A comma-separated list containing all allowable compression algorithms.

Syntax

sshtunnelcontrol.SSHCompressionAlgorithms[=string]

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 control 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 control:

  • zlib
  • zlib@openssh.com
  • none

Data Type

String

SSHEncryptionAlgorithms Property (SSHTunnel Control)

A comma-separated list containing all allowable encryption algorithms.

Syntax

sshtunnelcontrol.SSHEncryptionAlgorithms[=string]

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 control 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 control:

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.

Data Type

String

SSHForwardHost Property (SSHTunnel Control)

The address of the remote host. Domain names are resolved to IP addresses.

Syntax

sshtunnelcontrol.SSHForwardHost[=string]

Default Value

""

Remarks

The SSHForwardHost property specifies the IP address (IP number in dotted internet format) or Domain Name of the remote host. It is set before a connection is attempted and cannot be changed once a connection is established.

If the SSHForwardHost property is set to a Domain Name, a DNS request is initiated, and upon successful termination of the request, the SSHForwardHost property is set to the corresponding address. If the search is not successful, an error is returned.

If the control 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.

Data Type

String

SSHForwardPort Property (SSHTunnel Control)

The TCP port in the remote host.

Syntax

sshtunnelcontrol.SSHForwardPort[=integer]

Default Value

0

Remarks

The SSHForwardPort property specifies a service port on the remote host to connect to.

A valid port number (a value between 1 and 65535) is required for the connection to take place. The property must be set before a connection is attempted and cannot be changed once a connection is established. Any attempt to change this property while connected will fail with an error.

Data Type

Integer

SSHHost Property (SSHTunnel Control)

The address of the SSH host.

Syntax

sshtunnelcontrol.SSHHost[=string]

Default Value

""

Remarks

The SSHHost property specifies the IP address (IP number in dotted internet format) or Domain Name of the remote host. It is set before a connection is attempted and cannot be changed once a connection is established.

If the SSHHost property is set to a Domain Name, a DNS request is initiated, and upon successful termination of the request, the SSHHost property is set to the corresponding address. If the search is not successful, an error is returned.

The SSHHost must be the same host that will be assumed for SSH as for the remote service being connected to.

Data Type

String

SSHPassword Property (SSHTunnel Control)

The password for SSH password-based authentication.

Syntax

sshtunnelcontrol.SSHPassword[=string]

Default Value

""

Remarks

SSHPassword specifies the password which is used to authenticate the client to the SSH server.

Data Type

String

SSHPort Property (SSHTunnel Control)

The port on the SSH server where the SSH service is running; by default, 22.

Syntax

sshtunnelcontrol.SSHPort[=integer]

Default Value

22

Remarks

The SSHPort specifies a service port on the SSH host to connect to.

A valid port number (a value between 1 and 65535) is required for the connection to take place. The property must be set before a connection is attempted and cannot be changed once a connection is established. Any attempt to change this property while connected will fail with an error.

Data Type

Integer

SSHUser Property (SSHTunnel Control)

The username for SSH authentication.

Syntax

sshtunnelcontrol.SSHUser[=string]

Default Value

""

Remarks

SSHUser specifies the username which is used to authenticate the client to the SSH server. This property is required.

Example (User/Password Auth): Control.SSHAuthMode = SftpSSHAuthModes.amPassword Control.SSHUser = "username" Control.SSHPassword = "password" Control.SSHLogon("server", 22) Example (Public Key Auth): Control.SSHAuthMode = SftpSSHAuthModes.amPublicKey Control.SSHUser = "username" Control.SSHCertStoreType = SSHCertStoreTypes.cstPFXFile; Control.SSHCertStore = "cert.pfx"; Control.SSHCertStorePassword = "certpassword"; Control.SSHCertSubject = "*"; Control.SSHLogon("server", 22)

Data Type

String

Config Method (SSHTunnel Control)

Sets or retrieves a configuration setting.

Syntax

sshtunnelcontrol.Config ConfigurationString

Remarks

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

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

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

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

Connect Method (SSHTunnel Control)

Connects to the SSH host without logging in.

Syntax

sshtunnelcontrol.Connect 

Remarks

This method establishes a connection with the SSHHost but does not log in. In most cases it is recommended to use the StartListening method which will both establish a connection and log in to the server.

This method may be useful in cases where it is desirable to separate the connection and logon operations, for instance confirming a host is available by first creating the connection.

DecodePacket Method (SSHTunnel Control)

Decodes a hex-encoded SSH packet.

Syntax

sshtunnelcontrol.DecodePacket EncodedPacket

Remarks

This method is used to decode an SSH packet created by EncodePacket.

Note: This method is only applicable for reading and creating SSH packets for use within the SSHCustomAuth event.

Disconnect Method (SSHTunnel Control)

This method disconnects the specified client.

Syntax

sshtunnelcontrol.Disconnect ConnectionId

Remarks

This method immediately disconnects from the server without first logging off.

In most cases the StopListening method should be used to logoff and disconnect from the server. Call the Disconnect method in cases where it is desirable to immediately disconnect without first logging off.

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

DoEvents Method (SSHTunnel Control)

Processes events from the internal message queue.

Syntax

sshtunnelcontrol.DoEvents 

Remarks

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

EncodePacket Method (SSHTunnel Control)

Hex encodes an SSH packet.

Syntax

sshtunnelcontrol.EncodePacket Packet

Remarks

This method is used to encode a raw SSH packet created by SetSSHParam.

Note: This method is only applicable for reading and creating SSH packets for use within the SSHCustomAuth event.

GetSSHParam Method (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.GetSSHParam Payload, Field

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 SSHChannelRequest. 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 SetSSHParam. 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 SetSSHParam.

Note: This method is only applicable for reading and creating SSH packets for use within the SSHCustomAuth event.

GetSSHParamBytes Method (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.GetSSHParamBytes Payload, Field

Remarks

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

Note: This method is only applicable for reading and creating SSH packets for use within the SSHCustomAuth event.

Reset Method (SSHTunnel Control)

Reset the control.

Syntax

sshtunnelcontrol.Reset 

Remarks

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

SetSSHParam Method (SSHTunnel Control)

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

Syntax

sshtunnelcontrol.SetSSHParam Payload, FieldType, FieldValue

Remarks

This method is used to build the payload portion of an SSH packet to be sent later by a call to SendSSHPacket. Payload should contain the result of a previous call to SetSSHParam. 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.

Note: This method is only applicable for reading and creating SSH packets for use within the SSHCustomAuth event.

Shutdown Method (SSHTunnel Control)

This method shuts down the server.

Syntax

sshtunnelcontrol.Shutdown 

Remarks

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

StartListening Method (SSHTunnel Control)

This method starts listening for incoming connections.

Syntax

sshtunnelcontrol.StartListening 

Remarks

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

To stop listening for new connections, call StopListening. To stop listening for new connections and to disconnect all existing clients, call Shutdown.

StopListening Method (SSHTunnel Control)

This method stops listening for new connections.

Syntax

sshtunnelcontrol.StopListening 

Remarks

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

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

Connected Event (SSHTunnel Control)

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

Syntax

Sub sshtunnelcontrol_Connected(ConnectionId As Integer, StatusCode As Integer, Description As String)

Remarks

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

If the connection fails, StatusCode has the error code returned by the system. Description contains a description of this code. The value of StatusCode is equal to the value of the system error. The corresponding Visual Basic error code can be obtained by adding 15001 to this value.

Please refer to the Error Codes section for more information.

ConnectionRequest Event (SSHTunnel Control)

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

Syntax

Sub sshtunnelcontrol_ConnectionRequest(Address As String, Port As Integer, Accept As Boolean)

Remarks

This event indicates an incoming connection. The connection is accepted by default. Address and Port will contain information about the remote host requesting the inbound connection. If you want to refuse it, you can set the Accept parameter to False.

DataIn Event (SSHTunnel Control)

This event is fired when data come in.

Syntax

Sub sshtunnelcontrol_DataIn(ConnectionId As Integer, Text As String, EOL As Boolean)

Remarks

Trapping the DataIn event is your only chance to get the data coming from the other end of the connection specified by ConnectionId. The incoming data are provided through the Text parameter.

EOL indicates whether or not the EOL string was found at the end of Text. If the EOL string was found, then EOL is True.

If Text is part of the data portion of length larger than either DefaultMaxLineLength or with no EOL strings in it, then EOL is False. Please note that this means that one or more DataIn events with EOL set to False can be received during a connection.

If the EOL property is "" (empty string), then EOL can be disregarded (it is always True).

Note: Events are not re-entrant. Performing time-consuming operations within this event will prevent it from firing again in a timely manner and may affect overall performance.

Disconnected Event (SSHTunnel Control)

Fired when a connection is closed.

Syntax

Sub sshtunnelcontrol_Disconnected(ConnectionId As Integer, StatusCode As Integer, Description As String)

Remarks

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

If the connection is broken for any other reason, StatusCode has the error code returned by the system. Description contains a description of this code. The value of StatusCode is equal to the value of the system error. The corresponding Visual Basic error code can be obtained by adding 15001 to this value.

Please refer to the Error Codes section for more information.

Note: When the control is disconnected from the SSH server for any reason the ConnectionId parameter will be -1.

Error Event (SSHTunnel Control)

Information about errors during data delivery.

Syntax

Sub sshtunnelcontrol_Error(ConnectionId As Integer, ErrorCode As Integer, Description As String)

Remarks

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

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.

Log Event (SSHTunnel Control)

Fires once for each log message.

Syntax

Sub sshtunnelcontrol_Log(LogLevel As Integer, Message As String, LogType As String)

Remarks

This event fires once for each log messages generated by the control. 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.

ReconnectAttempt Event (SSHTunnel Control)

Fires when attempting to reconnect.

Syntax

Sub sshtunnelcontrol_ReconnectAttempt(Host As String, Port As Integer, RetryCount As Integer, RetriesRemaining As Integer, MaxRetryCount As Integer, RetryInterval As Integer, RetryType As Integer, RemoteListeningPort As Integer, Cancel As Boolean)

Remarks

This event fires both when attempting to reconnect to the SSHHost and when re-establishing a SSH tunnel.

Only applicable when AutoReconnect is enabled. To determine which type of connection is being established check the RetryType parameter.

The following table provides details about the parameters.

Host The SSH host to which the connection is attempted.
Port The Port on the SSH host to which the connection is attempted.
RetryCount The current retry attempt. For instance, this may be attempt number 2 out of 5, then RetryCount will hold the value 2.
RetriesRemaining The number of retries remaining after this attempt. This number does not include the current attempt. If MaxRetryCount is set to unlimited this will return -1.
MaxRetryCount The maximum number of retries as specified in MaxRetryCount.
RetryInterval The interval (in seconds) between retry attempts as specified in RetryInterval.
RetryType The type of connection being retried. Possible values are:
  • 0 - SSH
  • 1 - Tunnel
RemoteListeningPort The port on the SSH host which the reverse tunnel will use. This is only applicable when RetryType is 1.
Cancel Maybe set within this event to cancel the retry attempts. If set to True no further retry attempts will be executed.

SSHCustomAuth Event (SSHTunnel Control)

Fired when the control is doing custom authentication.

Syntax

Sub sshtunnelcontrol_SSHCustomAuth(Packet As String)

Remarks

SSHCustomAuth is fired during the user authentication stage of the SSH logon process if SSHAuthMode is set to amCustom. Packet contains the raw last SSH packet sent by the server, in HEX-encoded format.

The client should create a new raw SSH packet to send to the server and set Packet to the HEX-encoded representation of the packet to send.

In all cases, Packet will start with the message type field.

To read the incoming packet call DecodePacket and then use the GetSSHParam and GetSSHParamBytes methods. To create a packet use the SetSSHParam method and then call EncodePacket to obtain a HEX-encoded value and assign this to the Packet parameter.

SSHKeyboardInteractive Event (SSHTunnel Control)

Fired when the control receives a request for user input from the server.

Syntax

Sub sshtunnelcontrol_SSHKeyboardInteractive(Name As String, Instructions As String, Prompt As String, Response As String, EchoResponse As Boolean)

Remarks

SSHKeyboardInteractive is fired during the user authentication stage of the SSH logon process. During authentication, the control will request a list of available authentication methods for the SSHUser. For example, if the SSHHost responds with "keyboard-interactive", the control will fire this event to allow the client application to set the password.

During authentication, the SSH server may respond with a request for the user's authentication information. Name is a server-provided value associated with the authentication method such as "CRYPTOCard Authentication". Instructions will contain specific instructions, also supplied by the server, for how the user should respond.

Along with these values, the server will also send at least one input Prompt to be displayed to and filled out by the user. Response should be set to the user's input, and will be sent back in the user authentication information response. EchoResponse is a server recommendation for whether or not the user's response should be echoed back during input.

Note: the server may send several prompts in a single packet. The control will fire the SSHKeyboardInteractive event once for each prompt.

SSHServerAuthentication Event (SSHTunnel Control)

Fired after the server presents its public key to the client.

Syntax

Sub sshtunnelcontrol_SSHServerAuthentication(HostKey As String, Fingerprint As String, KeyAlgorithm As String, CertSubject As String, CertIssuer As String, Status As String, Accept As Boolean)

Remarks

This event is where the client can decide whether to continue with the connection process or not. If the public key is known to be a valid key for the SSH server, Accept should be set to True within the event. Otherwise, the server will not be authenticated and the connection will be broken.

Accept will be True only if either HostKey or Fingerprint is identical to the value of SSHAcceptServerHostKey.

Accept may be set to True manually to accept the server host key.

Note that SSH's security inherently relies on client verification of the host key. Ignoring the host key and always setting Accept to true is strongly discouraged, and could cause potentially serious security vulnerabilities in your application. It is recommended that clients maintain a list of known keys for each server and check HostKey against this list each time a connection is attempted.

Host Key contains the full binary text of the key, in the same format used internally by SSH.

Fingerprint holds the SHA-256 hash of HostKey in the hex-encoded form: 0a:1b:2c:3d. To configure the hash algorithm used to calculate this value see SSHFingerprintHashAlgorithm.

KeyAlgorithm identifies the host key algorithm. Supported values are:

  • ssh-rsa
  • ssh-dss
  • rsa-sha2-256
  • rsa-sha2-512
  • x509v3-sign-rsa
  • x509v3-sign-dss
  • ecdsa-sha2-nistp256
  • ecdsa-sha2-nistp384
  • ecdsa-sha2-nistp521
To limit the accepted host key algorithms refer to SSHPublicKeyAlgorithms.

CertSubject is the subject of the certificate. This is only applicable when KeyAlgorithm is "x509v3-sign-rsa" or "x509v3-sign-dss".

CertIssuer is the issuer of the certificate. This is only applicable when KeyAlgorithm is "x509v3-sign-rsa" or "x509v3-sign-dss".

Status is reserved for future use.

SSHStatus Event (SSHTunnel Control)

Shows the progress of the secure connection.

Syntax

Sub sshtunnelcontrol_SSHStatus(Message As String)

Remarks

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

Config Settings (SSHTunnel Control)

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

SSHTunnel Config Settings

AutoReconnect:   Whether to automatically reconnect.

This setting controls automatic recovery of the SSH connection. If logon is disrupted or the channel is closed the component can be configured to attempt reconnection automatically. Possible values are:

ValueDescription
0 (None) Do not automatically reconnect.
1 (Default) Reconnect if an existing connection is broken.
2 (Always) Retry the initial logon as well as recover an existing connection.
See MaxRetryCount and RetryInterval for additional related settings.
MaxRetryCount:   The maximum number of retries when reconnecting.

This setting defines the maximum number of connection attempts performed when re-establishing a broken connection. This setting only applies when AutoReconnect is enabled. By default, the component will reconnect forever.

RetryInterval:   The interval in seconds between reconnect attempts.

This setting specifies the number of seconds between reconnection attempts. This setting only applies when AutoReconnect is enabled. The default value is 5.

ShutdownChannelOnEOF:   Whether the client will shutdown the channel after receiving an EOF packet from the remote host.

The default value is False. Set this to True to send the channel close packet when an EOF packet is received.

SSHClient Config Settings

ChannelDataEOL[ChannelId]:   Used to break the incoming data stream into chunks.

By default MaxChannelDataLength is 0 and ChannelDataEOL is an empty string. SSHChannelData fires whenever an SSH_MSG_CHANNEL_DATA packet is received.

If MaxChannelDataLength > 0 and ChannelDataEOL is a non-empty string the control will internally buffer data waiting to fire SSHChannelData until either MaxChannelDataLength is reached or ChannelDataEOL is found, whichever comes first. Query ChannelDataEOLFound to know which condition was met. The buffer is reset any time SSHChannelData fires.

ChannelDataEOL and MaxChannelDataLength MUST be set together or unexpected behavior could occur.

ChannelDataEOLFound[ChannelId]:   Determines if ChannelDataEOL was found.

If ,then ChannelDataEOL was found. If , then MaxChannelDataLength was reached.

This config is only valid when queried inside SSHChannelData, MaxChannelDataLength > 0, and ChannelDataEOL is non-empty.

ClientSSHVersionString:   The SSH version string used by the control.

This configuration setting specifies the SSH version string used by the control. The default value is "SSH-2.0-IPWorks SSH Client 2022".

Most SSH servers expect the SSH version string to have the expected format "SSH-protocol version-software version". See above for an example.

EnablePageantAuth:   Whether to use a key stored in Pageant to perform client authentication.

This setting controls whether Pageant authentication is disabled, enabled, or required. When enabled or required, the control attempts to communicate with PuTTY's ssh-agent, called "Pageant", over shared memory to perform public key authentication. Possible values and the corresponding behavior is described below:

ValueDescription
0 (Disabled - default) No communication with Pageant is attempted.
1 (Enabled) Pageant authentication is used if available. If Pageant is not running, or does not contain the expected key no error is thrown.
2 (Required) Only Pageant authentication is used. If Pageant is not running, or does not contain the expected key an error is thrown.

Example enabling Pageant: component.Config("EnablePageantAuth=1"); component.SSHUser = "sshuser"; component.SSHLogon("localhost", 22);

Note: This functionality is only available on Windows.

KerberosDelegation:   If true, asks for credentials with delegation enabled during authentication.

The default value is "True". If set to "False", the client will not ask for credentials delegation support during authentication. Note that even if the client asks for delegation, the server/KDC might not grant it and authentication will still succeed.

KerberosRealm:   The fully qualified domain name of the Kerberos Realm to use for GSSAPI authentication.

This property may be set to the fully qualified (DNS) name of the kerberos realm (or Windows Active Directory domain name) to use during GSSAPI authentication. This can be used to force authentication with a given realm if the client and server machines are not part of the same domain.

KerberosSPN:   The Kerberos Service Principal Name of the SSH host.

This property can be set to specify the Service Principal Name (SPN) associated with the SSH service on the remote host. This will usually be in the form "host/fqdn.of.sshhost[@REALM]". If not specified, the control will assume the SPN is based on the value of the SSHHost property and the kerberos realm used for authentication.

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 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.

MaxChannelDataLength[ChannelId]:   The maximum amount of data to accumulate when no ChannelDataEOL is found.

By default MaxChannelDataLength is 0 and ChannelDataEOL is an empty string. SSHChannelData fires whenever an SSH_MSG_CHANNEL_DATA packet is received.

If MaxChannelDataLength > 0 and ChannelDataEOL is a non-empty string the control will internally buffer data waiting to fire SSHChannelData until either MaxChannelDataLength is reached or ChannelDataEOL is found, whichever comes first. Query ChannelDataEOLFound to know which condition was met. The buffer is reset any time SSHChannelData fires.

ChannelDataEOL and MaxChannelDataLength MUST be set together or unexpected behavior could occur.

MaxPacketSize:   The maximum packet size of the channel, in bytes.

This setting specifies the maximum size of an individual data packet, in bytes, that can be sent to the sender.

MaxWindowSize:   The maximum window size allowed for the channel, in bytes.

This setting specifies how many bytes of channel data can be sent to the sender of this message without adjusting the window. Note that this value may be changed during the connection, but the window size can only be increased, not decreased.

PasswordPrompt:   The text of the password prompt used in keyboard-interactive authentication.

This setting optionally specifies a pattern to be matched to the prompt received from the server during keyboard-interactive authentication. If a matching prompt is detected the control automatically responds to the prompt with the password specified by SSHPassword.

This provides an easy way to automatically reply to prompts with the password if one is presented by the server. The password will be auto-filled in the Response parameter of the SSHKeyboardInteractive event in the case of a match.

The following special characters are supported for pattern matching:

? Any single character.
* Any characters or no characters (e.g., C*t matches Cat, Cot, Coast, Ct).
[,-] A range of characters (e.g., [a-z], [a], [0-9], [0-9,a-d,f,r-z]).
\ The slash is ignored and exact matching is performed on the next character.

If these characters need to be used as a literal in a pattern, then they must be escaped by surrounding them with brackets []. Note: "]" and "-" do not need to be escaped. See below for the escape sequences:

CharacterEscape Sequence
? [?]
* [*]
[ [[]
\ [\]

For example, to match the value [Something].txt, specify the pattern [[]Something].txt.

PreferredDHGroupBits:   The size (in bits) of the preferred modulus (p) to request from the server.

This may be when using the diffie-hellman-group-exchange-sha1 or diffie-hellman-group-exchange-sha256 key exchange algorithms to control the preferred size, in bits, of the modulus (p) prime number to request from the server. Acceptable values are between 1024 and 8192.

RecordLength:   The length of received data records.

If set to a positive value, this setting defines the length of data records to be received. The control will accumulate data until RecordLength is reached and only then fire the DataIn 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 DataIn event.

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

ServerSSHVersionString:   The remote host's SSH version string.

This will return the remote host's SSH version string, which can help when identifying problematic servers. This configuration setting is read-only.

SignedSSHCert:   The CA signed client public key used when authenticating.

When authenticating via public key authentication this setting may be set to the CA signed client's public key. This is useful when the server has been configured to trust client keys signed by a particular CA. For instance: component.Config("SignedSSHCert=ssh-rsa-cert-v01@openssh.com AAAAB3NzaC1yc2EAAAADAQABAAAB..."); The algorithm such as ssh-rsa-cert-v01@openssh.com in the above string is used as part of the authentication process. To use a different algorithm simply change this value. For instance all of the following are acceptable with the same signed public key:

  • ssh-rsa-cert-v01@openssh.com AAAAB3NzaC1yc2EAAAADAQABAAAB...
  • rsa-sha2-256-cert-v01@openssh.com AAAAB3NzaC1yc2EAAAADAQABAAAB...
  • rsa-sha2-512-cert-v01@openssh.com AAAAB3NzaC1yc2EAAAADAQABAAAB...

SSHAcceptAnyServerHostKey:   If set the control will accept any key presented by the server.

The default value is "False". Set this to "True" to accept any key presented by the server.

SSHAcceptServerCAKey:   The CA public key that signed the server's host key.

If the server's host key was signed by a CA, this setting may be used to specify the CA's public key. If specified the control will trust any server's host key that was signed by the CA. For instance: component.Config("SSHAcceptServerCAKey=ssh-rsa AAAAB3NzaC1yc2EAAAADAQAB...");

SSHAcceptServerHostKeyFingerPrint:   The fingerprint of the server key to accept.

This may be set to a comma-delimited collection of 16-byte MD5 fingerprints that should be accepted as the host's key. You may supply it by HEX encoding the values in the form "0a:1b:2c:3d". Example: SSHClient.Config("SSHAcceptServerHostKeyFingerprint=0a:1b:2c:3d"); If the server's fingerprint matches one of the values supplied, the control will accept the host key.

SSHFingerprintHashAlgorithm:   The algorithm used to calculate the fingerprint.

This configuration setting controls which hash algorithm is used to calculate the hostkey's fingerprint, displayed when SSHServerAuthentication fires. Valid values are:

  • MD5
  • SHA1
  • SHA256 (default)
SSHFingerprintMD5:   The server hostkey's MD5 fingerprint.

This setting may be queried in SSHServerAuthentication to get the server hostkey's MD5 fingerprint.

SSHFingerprintSHA1:   The server hostkey's SHA1 fingerprint.

This setting may be queried in SSHServerAuthentication to get the server hostkey's SHA1 fingerprint.

SSHFingerprintSHA256:   The server hostkey's SHA256 fingerprint.

This setting may be queried in SSHServerAuthentication to get the server hostkey's SHA256 fingerprint.

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 control will continue to send keep alive packets until SSHKeepAliveCountMax is reached. If this is reached the control 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 control 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 control 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==.
SSHKeyRenegotiate:   Causes the component to renegotiate the SSH keys.

Once this setting is queried, the component will renegotiate the SSH keys with the remote host.

Example: SSHClient.Config("SSHKeyRenegotiate")

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 enabled signature algorithms that may be used when attempting public key authentication.

This setting specifies a list of signature algorithms that may be used 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. At runtime the control will evaluate the specified algorithms and if the algorithm is applicable to the certificate specified in SSHCert it will be used. If the algorithm is not applicable the control will evaluate the next algorithm. 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,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519.

rsa-sha2-256 and rsa-sha2-512 notes

The control will query the server for supported algorithms when connecting. If the server indicates support for rsa-sha2-256 or rsa-sha2-512 and the algorithm is present in the list defined by this setting (as in the default value), that algorithm will be used instead of ssh-rsa even when ssh-rsa appears first in the list.

For the rsa-sha2-256 and rsa-sha2-512 algorithms to be automatically preferred the server must support the ext-info-c mechanism. In practice, older servers do not support this and in that case ssh-rsa will be used since it appears first in the list. Newer servers do support this mechanism and in that case rsa-sha2-256 or rsa-sha2-512 will be used even though it appears after ssh-rsa.

This behavior has been carefully designed to provide maximum compatibility while automatically using more secure algorithms when connecting to servers which support them.

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-*
TryAllAvailableAuthMethods:   If set to true, the control will try all available authentication methods.

The default value is . When set to , the control will try to authenticate using all methods that it has credentials for and the server supports.

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 control will indicate support for strict key exchange by automatically including the pseudo-algorithm kex-strict-c-v00@openssh.com for client controls and kex-strict-s-v00@openssh.com for server controls 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 control 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 control.
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.

WaitForChannelClose:   Whether to wait for channels to be closed before disconnected.

This setting controls whether the control will wait for a server response to the SSH_MSG_CHANNEL_CLOSE when disconnecting. When the control disconnects it will first attempt to close all open channels by sending a SSH_MSG_CHANNEL_CLOSE for each channel. This setting controls whether the control will wait for a server response after sending the messages.

When True (default) the control will wait for a response to the channel close message until the responses have been received, the server closes the connection, or Timeout seconds is reached.

When False the control will still send the channel close messages but will not wait for a response and will proceed to close the connection.

WaitForServerDisconnect:   Whether to wait for the server to close the connection.

This setting controls whether to wait for the server to close the connection when SSHLogoff is called.

When set to True the control will initiate the disconnection sequence by sending SSH_MSG_DISCONNECT but will not close the connection, and instead will wait for the server to close the connection. Setting this to True may be beneficial in circumstances where many connections are being established, to avoid port exhaustion when sockets are in a TIME_WAIT state. Allowing the server to close the connection avoids the TIME_WAIT state of socket on the client machine.

When set to False (default) the client will close the connection. It is recommended to use this value unless there is a specific need to change it.

TCPClient Config Settings

ConnectionTimeout:   Sets a separate timeout value for establishing a connection.

When set, this configuration setting allows you to specify a different timeout value for establishing a connection. Otherwise, the control will use Timeout for establishing a connection and transmitting/receiving data.

FirewallAutoDetect:   Tells the control whether or not to automatically detect and use firewall system settings, if available.

This configuration setting is provided for use by controls that do not directly expose Firewall properties.

FirewallHost:   Name or IP address of firewall (optional).

If a FirewallHost is given, requested connections will be authenticated through the specified firewall when connecting.

If the FirewallHost setting is set to a Domain Name, a DNS request is initiated. Upon successful termination of the request, the FirewallHost setting is set to the corresponding address. If the search is not successful, an error is returned.

Note: This setting is provided for use by controls that do not directly expose Firewall properties.

FirewallPassword:   Password to be used if authentication is to be used when connecting through the firewall.

If FirewallHost is specified, the FirewallUser and FirewallPassword settings are used to connect and authenticate to the given firewall. If the authentication fails, the control fails with an error.

Note: This setting is provided for use by controls that do not directly expose Firewall properties.

FirewallPort:   The TCP port for the FirewallHost;.

The FirewallPort is set automatically when FirewallType is set to a valid value.

Note: This configuration setting is provided for use by controls that do not directly expose Firewall properties.

FirewallType:   Determines the type of firewall to connect through.

The appropriate values are as follows:

0No firewall (default setting).
1Connect through a tunneling proxy. FirewallPort is set to 80.
2Connect through a SOCKS4 Proxy. FirewallPort is set to 1080.
3Connect through a SOCKS5 Proxy. FirewallPort is set to 1080.
10Connect through a SOCKS4A Proxy. FirewallPort is set to 1080.

Note: This setting is provided for use by controls that do not directly expose Firewall properties.

FirewallUser:   A user name if authentication is to be used connecting through a firewall.

If the FirewallHost is specified, the FirewallUser and FirewallPassword settings are used to connect and authenticate to the Firewall. If the authentication fails, the control fails with an error.

Note: This setting is provided for use by controls that do not directly expose Firewall properties.

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

When set, TCPKeepAlive 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 configuration setting specifies the interval at which the successive keep-alive packets are sent in milliseconds. This system default if this value is not specified here is 1 second.

Note: This value is not applicable in macOS.

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

When set, TCPKeepAlive will automatically be set to True. By default, the operating system will determine the time a connection is idle before a Transmission Control Protocol (TCP) keep-alive packet is sent. This system default if this value is not specified here is 2 hours. In many cases, a shorter interval is more useful. Set this value to the desired interval in milliseconds.

Linger:   When set to True, connections are terminated gracefully.

This property controls how a connection is closed. The default is True.

In the case that Linger is True (default), two scenarios determine how long the connection will linger. In the first, if LingerTime is 0 (default), the system will attempt to send pending data for a connection until the default IP timeout expires.

In the second scenario, if LingerTime is a positive value, the system will attempt to send pending data until the specified LingerTime is reached. If this attempt fails, then the system will reset the connection.

The default behavior (which is also the default mode for stream sockets) might result in a long delay in closing the connection. Although the control returns control immediately, the system could hold system resources until all pending data are sent (even after your application closes).

Setting this property to False forces an immediate disconnection. If you know that the other side has received all the data you sent (e.g., by a client acknowledgment), setting this property to False might be the appropriate course of action.

LingerTime:   Time in seconds to have the connection linger.

LingerTime is the time, in seconds, the socket connection will linger. This value is 0 by default, which means it will use the default IP timeout.

LocalHost:   The name of the local host through which connections are initiated or accepted.

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

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

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

LocalPort:   The port in the local host where the control binds.

This must be set before a connection is attempted. It instructs the control to bind to a specific port (or communication endpoint) in the local machine.

Setting this to 0 (default) enables the system to choose a port at random. The chosen port will be shown by LocalPort after the connection is established.

LocalPort cannot be changed once a connection is made. Any attempt to set this when a connection is active will generate an error.

This; setting is useful when trying to connect to services that require a trusted port in the client side. An example is the remote shell (rsh) service in UNIX systems.

MaxLineLength:   The maximum amount of data to accumulate when no EOL is found.

MaxLineLength is the size of an internal buffer, which holds received data while waiting for an EOL string.

If an EOL string is found in the input stream before MaxLineLength bytes are received, the DataIn event is fired with the EOL parameter set to True, and the buffer is reset.

If no EOL is found, and MaxLineLength bytes are accumulated in the buffer, the DataIn event is fired with the EOL parameter set to False, and the buffer is reset.

The minimum value for MaxLineLength is 256 bytes. The default value is 2048 bytes.

MaxTransferRate:   The transfer rate limit in bytes per second.

This configuration setting can be used to throttle outbound TCP traffic. Set this to the number of bytes to be sent per second. By default, this is not set and there is no limit.

ProxyExceptionsList:   A semicolon separated list of hosts and IPs to bypass when using a proxy.

This configuration setting optionally specifies a semicolon-separated list of hostnames or IP addresses to bypass when a proxy is in use. When requests are made to hosts specified in this property, the proxy will not be used. For instance:

www.google.com;www.nsoftware.com

TCPKeepAlive:   Determines whether or not the keep alive socket option is enabled.

If set to True, the socket's keep-alive option is enabled and keep-alive packets will be sent periodically to maintain the connection. Set KeepAliveTime and KeepAliveInterval to configure the timing of the keep-alive packets.

Note: This value is not applicable in Java.

TcpNoDelay:   Whether or not to delay when sending packets.

When 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.

UseIPv6:   Whether to use IPv6.

When set to 0 (default), the control will use IPv4 exclusively. When set to 1, the control will use IPv6 exclusively. To instruct the control to prefer IPv6 addresses, but use IPv4 if IPv6 is not supported on the system, this setting should be set to 2. The default value is 0. Possible values are:

0 IPv4 Only
1 IPv6 Only
2 IPv6 with IPv4 fallback

Socket Config Settings

AbsoluteTimeout:   Determines whether timeouts are inactivity timeouts or absolute timeouts.

If AbsoluteTimeout is set to True, any method which does not complete within Timeout seconds will be aborted. By default, AbsoluteTimeout is False, and the timeout is an inactivity timeout.

Note: This option is not valid for UDP ports.

FirewallData:   Used to send extra data to the firewall.

When the firewall is a tunneling proxy, use this property to send custom (additional) headers to the firewall (e.g. headers for custom authentication schemes).

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

This is the size of an internal queue in the 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 control is activated the InBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.

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

This is the size of an internal queue in the TCP/IP stack. You can increase or decrease its size depending on the amount of data that you will be sending. 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 control is activated the OutBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.

TCPServer Config Settings

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

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

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

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

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

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 control 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.

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 control. 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.

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 control 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.

UseIPv6:   Whether to use IPv6.

When set to 0 (default), the control will use IPv4 exclusively. When set to 1, the control will use IPv6 exclusively. When set to 2, the control 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

Base Config Settings

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

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

The following is a list of valid code page identifiers:

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

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 to mask sensitive data. The default is .

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

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

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

Setting this setting to tells the control to use the internal implementation instead of using the system security libraries.

This setting is set to by default on all platforms.

Trappable Errors (SSHTunnel Control)

SSHTunnel Errors

20101    You cannot change the RemotePort at this time. A connection is in progress.
20102    You cannot change the RemoteHost at this time. A connection is in progress.
20103    The RemoteHost address is invalid (0.0.0.0).
20105    TCPServer is already listening.
20107    Cannot change LocalPort when TCPServer is Listening.
20108    Cannot change LocalHost when TCPServer is Listening.
20109    Cannot change MaxConnections when TCPServer is Listening.
20113    You cannot change MaxLineLength at this time. A connection is in progress.
20117    RemotePort cannot be zero. Please specify a valid service port number.
20127    Invalid ConnectionId.
21202    Could not forward connection. A detailed message follows.
21203    Could not forward connection/channel data. A detailed message follows.

SSHClient Errors

21002    Server has disconnected.
21003    Protocol version unsupported or other issue with version string.
21004    Cannot negotiate algorithms.
21006    Selected algorithm unsupported.
21007    Cannot set keys.
21011    Unexpected algorithm.
21012    Cannot create exchange hash.
21013    Cannot make key.
21014    Cannot sign data.
21015    Cannot encrypt packet.
21016    Cannot decrypt packet.
21017    Cannot decompress packet.
21021    Failure to open channel.
21022    Invalid channel ID.
21023    Invalid channel data.
21024    Invalid channel message.
21025    SSH message unimplemented.
21028    Server message unsupported.
21031    Server's host key was rejected. The host key may be accepted within the SSHServerAuthentication event or using the SSHAcceptServerHostKey property.
21032    Cannot verify server's host key.
21033    Authentication failed. Check description for details.
21034    Channel request failed.
21035    Diffie-Hellman exchange failed.
21037    SSH connection failed.
21038    SSH reconnect limit reached.
21039    Elliptic Curve Diffie-Hellman exchange failed.
21040    SSH keep-alive limit reached.
21099    Request failure.
21131    Would block error.
21134    Would block, reason: key reExchange.

The control may also return one of the following error codes, which are inherited from other controls.

TCPClient Errors

20101    You cannot change the RemotePort at this time. A connection is in progress.
20102    You cannot change the RemoteHost (Server) at this time. A connection is in progress.
20103    The RemoteHost address is invalid (0.0.0.0).
20105    Already connected. If you want to reconnect, close the current connection first.
20107    You cannot change the LocalPort at this time. A connection is in progress.
20108    You cannot change the LocalHost at this time. A connection is in progress.
20113    You cannot change MaxLineLength at this time. A connection is in progress.
20117    RemotePort cannot be zero. Please specify a valid service port number.
20118    You cannot change the UseConnection option while the control is active.
20136    Operation would block.
20202    Timeout.
20212    Action impossible in control's present state.
20213    Action impossible while not connected.
20214    Action impossible while listening.
20302    Timeout.
20303    Could not open file.
20435    Unable to convert string to selected CodePage.
21106    Already connecting. If you want to reconnect, close the current connection first.
21118    You need to connect first.
21120    You cannot change the LocalHost at this time. A connection is in progress.
21121    Connection dropped by remote host.

TCP/IP Errors

25005    [10004] Interrupted system call.
25010    [10009] Bad file number.
25014    [10013] Access denied.
25015    [10014] Bad address.
25023    [10022] Invalid argument.
25025    [10024] Too many open files.
25036    [10035] Operation would block.
25037    [10036] Operation now in progress.
25038    [10037] Operation already in progress.
25039    [10038] Socket operation on non-socket.
25040    [10039] Destination address required.
25041    [10040] Message too long.
25042    [10041] Protocol wrong type for socket.
25043    [10042] Bad protocol option.
25044    [10043] Protocol not supported.
25045    [10044] Socket type not supported.
25046    [10045] Operation not supported on socket.
25047    [10046] Protocol family not supported.
25048    [10047] Address family not supported by protocol family.
25049    [10048] Address already in use.
25050    [10049] Can't assign requested address.
25051    [10050] Network is down.
25052    [10051] Network is unreachable.
25053    [10052] Net dropped connection or reset.
25054    [10053] Software caused connection abort.
25055    [10054] Connection reset by peer.
25056    [10055] No buffer space available.
25057    [10056] Socket is already connected.
25058    [10057] Socket is not connected.
25059    [10058] Can't send after socket shutdown.
25060    [10059] Too many references, can't splice.
25061    [10060] Connection timed out.
25062    [10061] Connection refused.
25063    [10062] Too many levels of symbolic links.
25064    [10063] File name too long.
25065    [10064] Host is down.
25066    [10065] No route to host.
25067    [10066] Directory not empty
25068    [10067] Too many processes.
25069    [10068] Too many users.
25070    [10069] Disc Quota Exceeded.
25071    [10070] Stale NFS file handle.
25072    [10071] Too many levels of remote in path.
25092    [10091] Network subsystem is unavailable.
25093    [10092] WINSOCK DLL Version out of range.
25094    [10093] Winsock not loaded yet.
26002    [11001] Host not found.
26003    [11002] Non-authoritative 'Host not found' (try again or check DNS setup).
26004    [11003] Non-recoverable errors: FORMERR, REFUSED, NOTIMP.
26005    [11004] Valid name, no data record (check DNS setup).