SSHTunnel Component

Properties Methods Events Configuration Settings Errors

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

Syntax

nsoftware.IPWorksSSH.Sshtunnel

Remarks

The SSHTunnel component 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 SSHCert 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, set Listening to true. The component will listen for connections on the interface identified by LocalHost and LocalPort.

When a client attempts to connect to the component, the component will fire a ConnectionRequest event that can be used to accept or reject the connection. If the connection is accepted, the component 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 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 component set up with Network A can be used to access any resource in Network B.

The SSHHost and SSHPort property 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 component 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.

Property List

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


Connected	Triggers a connection or disconnection.
ConnectionBacklog	The maximum number of pending connections maintained by the TCP/IP subsystem.
Connections	A collection of currently connected clients.
DefaultEOL	A default EOL value to be used by incoming connections.
DefaultSingleLineMode	Tells the component whether or not to treat new connections as line-oriented.
DefaultTimeout	An initial timeout value to be used by incoming connections.
Firewall	A set of properties related to firewall access.
KeepAlive	When True, KEEPALIVE packets are enabled (for long connections).
Linger	When set to True, connections are terminated gracefully.
Listening	If True, the component accepts incoming connections on LocalPort.
LocalHost	The name of the local host or user-assigned IP interface through which connections are initiated or accepted.
LocalPort	The TCP port in the local host where IPPort binds.
SSHAcceptServerHostKey	Instructs the component to accept the server host key that matches the supplied key.
SSHAuthMode	The authentication method to be used the component when calling SSHLogon .
SSHCert	A certificate to be used for authenticating the SSHUser .
SSHCompressionAlgorithms	A comma-separated list containing all allowable compression algorithms.
SSHEncryptionAlgorithms	A comma-separated list containing all allowable compression algorithms.
SSHForwardHost	The address of the remote host. Domain names are resolved to IP addresses.
SSHForwardPort	The TCP port in the remote host.
SSHHost	The address of the SSH host.
SSHPassword	The password for SSH password-based authentication.
SSHPort	The port on the SSH server where the SSH service is running; by default, 22.
SSHUser	The username for SSH authentication.

Method List

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


Config	Sets or retrieves a configuration setting .
DecodePacket	Decodes a hex-encoded SSH packet.
Disconnect	Disconnect the specified client.
DoEvents	Processes events from the internal message queue.
EncodePacket	Hex encodes an SSH packet.
GetSSHParam	Used to read a field from an SSH packet's payload.
GetSSHParamBytes	Used to read a field from an SSH packet's payload.
SetSSHParam	Used to write a field to the end of a payload.
Shutdown	Shuts down the server.

Event List

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


Connected	Fired immediately after a connection completes (or fails).
ConnectionRequest	Fired when a request for connection comes from a remote host.
DataIn	Fired when data comes in.
Disconnected	Fired when a connection is closed.
Error	Information about errors during data delivery.
SSHCustomAuth	Fired when the component is doing custom authentication.
SSHKeyboardInteractive	Fired when the component receives a request for user input from the server.
SSHServerAuthentication	Fired after the server presents its public key to the client.
SSHStatus	Shows the progress of the secure connection.

Configuration Settings

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


ClientSSHVersionString	The SSH version string used by the component.
SignedSSHCert	The CA signed client public key used when authenticating.
SSHAcceptServerCAKey	The CA public key that signed the server's host key.
SSHAcceptAnyServerHostKey	If set the component will accept any key presented by the server.
SSHAcceptServerHostKeyFingerPrint	The fingerprint of the server key to accept.
SSHKeyExchangeAlgorithms	Specifies the supported key exchange algorithms.
SSHMacAlgorithms	Specifies the supported Mac algorithms.
SSHKeyRenegotiate	Causes the component to renegotiate the SSH keys.
KeyRenegotiationThreshold	Sets the threshold for the SSH Key Renegotiation.
KerberosRealm	The fully qualified domain name of the Kerberos Realm to use for GSSAPI authentication.
KerberosDelegation	If true, asks for credentials with delegation enabled during authentication.
KerberosSPN	The Kerberos Service Principal Name of the SSH host.
LogSSHPackets	If true, detailed SSH packet logging is performed.
MaxPacketSize	The maximum packet size of the channel, in bytes.
MaxWindowSize	The maximum window size allowed for the channel, in bytes.
PreferredDHGroupBits	The size (in bits) of the preferred modulus (p) to request from the server.
ConnectionTimeout	Sets a separate timeout value for establishing a connection.
FirewallAutoDetect	Tells the component whether or not to automatically detect and use firewall system settings, if available.
FirewallHost	Name or IP address of firewall (optional).
FirewallPassword	Password to be used if authentication is to be used when connecting through the firewall.
FirewallPort	The TCP port for the FirewallHost;.
FirewallType	Determines the type of firewall to connect through.
FirewallUser	A user name if authentication is to be used connecting through a firewall.
KeepAliveTime	The inactivity time in milliseconds before a TCP keep-alive packet is sent.
KeepAliveInterval	The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.
Linger	When set to True, connections are terminated gracefully.
LingerTime	Time in seconds to have the connection linger.
LocalHost	The name of the local host through which connections are initiated or accepted.
LocalPort	The TCP port in the local host where the component binds.
MaxLineLength	The maximum amount of data to accumulate when no EOL is found.
MaxTransferRate	The transfer rate limit in bytes per second.
RecordLength	The length of received data records.
TCPKeepAlive	Determines whether or not the keep alive socket option is enabled.
UseIPv6	Whether to use IPv6.
TcpNoDelay	Whether or not to delay when sending packets.
AbsoluteTimeout	Determines whether timeouts are inactivity timeouts or absolute timeouts.
FirewallData	Used to send extra data to the firewall.
InBufferSize	The size in bytes of the incoming queue of the socket.
OutBufferSize	The size in bytes of the outgoing queue of the socket.
BindExclusively	Whether or not the component considers a local port reserved for exclusive use.
InBufferSize	The size in bytes of the incoming queue of the socket.
MaxConnections	The maximum number of connections available.
OutBufferSize	The size in bytes of the outgoing queue of the socket.
KeepAliveTime	The inactivity time in milliseconds before a TCP keep-alive packet is sent.
KeepAliveInterval	The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.
RecordLength[ConnectionId]	The length of received data records.
TcpNoDelay	Whether or not to delay when sending packets.
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