SshTunnel Xojo Plugin Reference Documentation

SshTunnel

Current Version: 9.5.0.73

The SSH tunnel class provides for the ability to run a self-contained SSH tunnel in a background thread. It can behave as a SOCKS proxy, accepting connections from SOCKS4 or SOCK5 proxy clients and fowarding connections through an SSH tunnel. This is the "dynamic port forwarding" mode of operation. It can also behave in a static port forwarding mode (where it accepts connections and forwards the connection to a pre-defined remote destination IP:port).

Object Creation

Dim sshTunnel As New Chilkat.SshTunnel

Properties

AbortCurrent
AbortCurrent As Boolean
Introduced in version 9.5.0.58

When set to True, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to False when the next method is called. When the abort occurs, this property is reset to False. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

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AcceptLog
AcceptLog As String

Contains an in-memory log of the listen thread. This will only contain content if the KeepAcceptLog property is True.

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AcceptLogPath
AcceptLogPath As String
Introduced in version 9.5.0.50

Specifies a log file to be kept for the activity in the listen thread.

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ConnectTimeoutMs
ConnectTimeoutMs As Int32

Maximum number of milliseconds to wait when connecting to an SSH server. The default value is 10000 (i.e. 10 seconds). A value of 0 indicates no timeout (wait forever).

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DebugLogFilePath
DebugLogFilePath As String

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

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DestHostname
DestHostname As String

The destination hostname or IP address (in dotted decimal notation) of the service (such as a database server). Data sent through the SSH tunnel is forwarded by the SSH server to this destination. Data received from the destination (by the SSH server) is forwarded back to the client through the SSH tunnel.

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DestPort
DestPort As Int32

The destination port of the service (such as a database server).

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DynamicPortForwarding
DynamicPortForwarding As Boolean
Introduced in version 9.5.0.50

If True, then this behaves as a SOCKS proxy server for inbound connections. When this property is True, the DestHostname and DestPort properties are unused because the destination IP:port is dynamically provided by the SOCKS client. The default value of this property is False.

When dynamic port forwarding is used, the InboundSocksVersion property must be set to 4 or 5. If inbound SOCKS5 is used, then the InboundSocksUsername and InboundSocksPassword may be set to the required login/password for a client to gain access.

More Information and Examples
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HostKeyFingerprint
HostKeyFingerprint As String (read-only)
Introduced in version 9.5.0.56

Set after connecting to an SSH server. The format of the fingerprint looks like this: "ssh-rsa 1024 68:ff:d1:4e:6c:ff:d7:b0:d6:58:73:85:07:bc:2e:d5"

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HttpProxyAuthMethod
HttpProxyAuthMethod As String

If an HTTP proxy requiring authentication is to be used, set this property to the HTTP proxy authentication method name. Valid choices are "Basic" or "NTLM".

Note: This is for the outbound connection to the SSH server. It is used when the outbound connection to the SSH server must go through an HTTP proxy.

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HttpProxyDomain
HttpProxyDomain As String

The NTLM authentication domain (optional) if NTLM authentication is used w/ the HTTP proxy.

Note: This is for the outbound connection to the SSH server. It is used when the outbound connection to the SSH server must go through an HTTP proxy.

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HttpProxyHostname
HttpProxyHostname As String

If an HTTP proxy is to be used, set this property to the HTTP proxy hostname or IPv4 address (in dotted decimal notation).

Note: This is for the outbound connection to the SSH server. It is used when the outbound connection to the SSH server must go through an HTTP proxy.

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HttpProxyPassword
HttpProxyPassword As String

If an HTTP proxy requiring authentication is to be used, set this property to the HTTP proxy password.

Note: This is for the outbound connection to the SSH server. It is used when the outbound connection to the SSH server must go through an HTTP proxy.

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HttpProxyPort
HttpProxyPort As Int32

If an HTTP proxy is to be used, set this property to the HTTP proxy port number. (Two commonly used HTTP proxy ports are 8080 and 3128.)

Note: This is for the outbound connection to the SSH server. It is used when the outbound connection to the SSH server must go through an HTTP proxy.

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HttpProxyUsername
HttpProxyUsername As String

If an HTTP proxy requiring authentication is to be used, set this property to the HTTP proxy login name.

Note: This is for the outbound connection to the SSH server. It is used when the outbound connection to the SSH server must go through an HTTP proxy.

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IdleTimeoutMs
IdleTimeoutMs As Int32

A tunnel will fail when progress for sending or receiving data halts for more than this number of milliseconds. The default value is 10,000 (which is 10 seconds). A timeout of 0 indicates an infinite wait time (i.e. no timeout).

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InboundSocksPassword
InboundSocksPassword As String
Introduced in version 9.5.0.50

If dynamic port forwarding is used, then this may be set to the password required for authenticating inbound connections.

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InboundSocksUsername
InboundSocksUsername As String
Introduced in version 9.5.0.50

If dynamic port forwarding is used, then this may be set to the username required for authenticating inbound connections. If no username is set, then the inbound connection needs no authentication.

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IsAccepting
IsAccepting As Boolean (read-only)

True if a background thread is running and accepting connections.

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KeepAcceptLog
KeepAcceptLog As Boolean

If True, then an in-memory log of the listen thread is kept. The default value is False.

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KeepTunnelLog
KeepTunnelLog As Boolean
Introduced in version 9.5.0.50

If True, then a log of the SSH tunnel thread activity is kept in memory. The default value is False.

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LastErrorHtml
LastErrorHtml As String (read-only)

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorText
LastErrorText As String (read-only)

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorXml
LastErrorXml As String (read-only)

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastMethodSuccess
LastMethodSuccess As Boolean
Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of True indicates success, a value of False indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = True and failure = False.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to True. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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ListenBindIpAddress
ListenBindIpAddress As String

In most cases, this property does not need to be set. It is provided for cases where it is required to bind the listen socket to a specific IP address (usually for computers with multiple network interfaces or IP addresses). For computers with a single network interface (i.e. most computers), this property should not be set. For multihoming computers, the default IP address is automatically used if this property is not set.

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ListenPort
ListenPort As Int32 (read-only)

If a port number equal to 0 is passed to BeginAccepting, then this property will contain the actual allocated port number used. Otherwise it is equal to the port number passed to BeginAccepting, or 0 if BeginAccepting was never called.

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OutboundBindIpAddress
OutboundBindIpAddress As String

In most cases, this property does not need to be set. It is provided for cases where it is required to bind the socket that is to connect to the SSH server (in the background thread) to a specific IP address (usually for computers with multiple network interfaces or IP addresses). For computers with a single network interface (i.e. most computers), this property should not be set. For multihoming computers, the default IP address is automatically used if this property is not set.

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OutboundBindPort
OutboundBindPort As Int32

Unless there is a specific requirement for binding to a specific port, leave this unset (at the default value of 0). (99.9% of all users should never need to set this property.)

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PreferIpv6
PreferIpv6 As Boolean
Introduced in version 9.5.0.70

If True, then use IPv6 over IPv4 when both are supported for a particular domain. The default value of this property is False, which will choose IPv4 over IPv6.

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SocksHostname
SocksHostname As String

The SOCKS4/SOCKS5 hostname or IPv4 address (in dotted decimal notation). This property is only used if the SocksVersion property is set to 4 or 5).

Note: This is for the outbound connection to the SSH server. It is used when the outbound connection to the SSH server must go through a SOCKS4 or SOCKS5 proxy.

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SocksPassword
SocksPassword As String

The SOCKS5 password (if required). The SOCKS4 protocol does not include the use of a password, so this does not apply to SOCKS4.

Note: This is for the outbound connection to the SSH server. It is used when the outbound connection to the SSH server must go through a SOCKS4 or SOCKS5 proxy.

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SocksPort
SocksPort As Int32

The SOCKS4/SOCKS5 proxy port. The default value is 1080. This property only applies if a SOCKS proxy is used (if the SocksVersion property is set to 4 or 5).

Note: This is for the outbound connection to the SSH server. It is used when the outbound connection to the SSH server must go through a SOCKS4 or SOCKS5 proxy.

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SocksUsername
SocksUsername As String

The SOCKS4/SOCKS5 proxy username. This property is only used if the SocksVersion property is set to 4 or 5).

Note: This is for the outbound connection to the SSH server. It is used when the outbound connection to the SSH server must go through a SOCKS4 or SOCKS5 proxy.

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SocksVersion
SocksVersion As Int32

SocksVersion May be set to one of the following integer values:

0 - No SOCKS proxy is used. This is the default.
4 - Connect via a SOCKS4 proxy.
5 - Connect via a SOCKS5 proxy.

Note: This is for the outbound connection to the SSH server. It is used when the outbound connection to the SSH server must go through a SOCKS4 or SOCKS5 proxy.

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SoRcvBuf
SoRcvBuf As Int32

Sets the receive buffer size socket option. Normally, this property should be left unchanged. The default value is 4194304.

This property can be increased if download performance seems slow. It is recommended to be a multiple of 4096.

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SoSndBuf
SoSndBuf As Int32

Sets the send buffer size socket option. Normally, this property should be left unchanged. The default value is 262144.

This property can be increased if upload performance seems slow. It is recommended to be a multiple of 4096. Testing with sizes such as 512K and 1MB is reasonable.

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TcpNoDelay
TcpNoDelay As Boolean

Controls whether the TCP_NODELAY socket option is used for the underlying TCP/IP socket. The default value is False. Setting this property equal to True disables the Nagle algorithm and allows for better performance when small amounts of data are sent.

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TunnelLog
TunnelLog As String
Introduced in version 9.5.0.50

Contains an in-memory log of the SSH tunnel thread. This will only contain content if the KeepTunnelLog property is True.

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TunnelLogPath
TunnelLogPath As String
Introduced in version 9.5.0.50

Set to keep a log file of the SSH tunnel thread.

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UncommonOptions
UncommonOptions As String
Introduced in version 9.5.0.73

This is a catch-all property to be used for uncommon needs. This property defaults to the empty string, and should typically remain empty.

As of v9.5.0.73, the only possible value is:

  • "KEX_DH_GEX_REQUEST_OLD" - Force the old Group Exchange message to be used. This would be used for very old SSH server implementations that do not use the RFC standard for diffie-hellman-group-exchange.

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VerboseLogging
VerboseLogging As Boolean

If set to True, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is False. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
Version As String (read-only)

Version of the component/library, such as "9.5.0.63"

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Methods

AuthenticatePk
Function AuthenticatePk(username As String, privateKey As Chilkat.SshKey) As Boolean
Introduced in version 9.5.0.50

Authenticates with the SSH server using public-key authentication. The corresponding public key must have been installed on the SSH server for the username. Authentication will succeed if the matching privateKey is provided.

Important: When reporting problems, please send the full contents of the LastErrorText property to support@chilkatsoft.com.

Returns True for success, False for failure.

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AuthenticatePkAsync (1)
Function AuthenticatePkAsync(username As String, privateKey As Chilkat.SshKey) As Chilkat.Task
Introduced in version 9.5.0.50

Creates an asynchronous task to call the AuthenticatePk method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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AuthenticatePw
Function AuthenticatePw(login As String, password As String) As Boolean
Introduced in version 9.5.0.50

Authenticates with the SSH server using a login and password.

An SSH session always begins by first calling Connect to connect to the SSH server, and then calling either AuthenticatePw or AuthenticatePk to login.

Important: When reporting problems, please send the full contents of the LastErrorText property to support@chilkatsoft.com.
Note: To learn about how to handle password change requests, see the PasswordChangeRequested property (above).

Returns True for success, False for failure.

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AuthenticatePwAsync (1)
Function AuthenticatePwAsync(login As String, password As String) As Chilkat.Task
Introduced in version 9.5.0.50

Creates an asynchronous task to call the AuthenticatePw method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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AuthenticatePwPk
Function AuthenticatePwPk(username As String, password As String, privateKey As Chilkat.SshKey) As Boolean
Introduced in version 9.5.0.50

Authentication for SSH servers that require both a password and private key. (Most SSH servers are configured to require one or the other, but not both.)

Important: When reporting problems, please send the full contents of the LastErrorText property to support@chilkatsoft.com.

Returns True for success, False for failure.

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AuthenticatePwPkAsync (1)
Function AuthenticatePwPkAsync(username As String, password As String, privateKey As Chilkat.SshKey) As Chilkat.Task
Introduced in version 9.5.0.50

Creates an asynchronous task to call the AuthenticatePwPk method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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AuthenticateSecPw
Function AuthenticateSecPw(login As Chilkat.SecureString, password As Chilkat.SecureString) As Boolean
Introduced in version 9.5.0.71

The same as AuthenticatePw, except the login and password strings are passed in secure string objects.

Returns True for success, False for failure.

More Information and Examples
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AuthenticateSecPwAsync (1)
Function AuthenticateSecPwAsync(login As Chilkat.SecureString, password As Chilkat.SecureString) As Chilkat.Task
Introduced in version 9.5.0.71

Creates an asynchronous task to call the AuthenticateSecPw method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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AuthenticateSecPwPk
Function AuthenticateSecPwPk(username As Chilkat.SecureString, password As Chilkat.SecureString, privateKey As Chilkat.SshKey) As Boolean
Introduced in version 9.5.0.71

The same as AuthenticatePwPk, except the login and password strings are passed in secure string objects.

Returns True for success, False for failure.

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AuthenticateSecPwPkAsync (1)
Function AuthenticateSecPwPkAsync(username As Chilkat.SecureString, password As Chilkat.SecureString, privateKey As Chilkat.SshKey) As Chilkat.Task
Introduced in version 9.5.0.71

Creates an asynchronous task to call the AuthenticateSecPwPk method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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BeginAccepting
Function BeginAccepting(listenPort As Int32) As Boolean

Starts a background thread for listening on listenPort. A new SSH tunnel is created and managed for each accepted connection. SSH tunnels are managed in a 2nd background thread: the SSH tunnel pool thread.

BeginAccepting starts a background thread that creates a socket, binds to the port, and begins listening. If the bind fails (meaning something else may have already bound to the same port), then the background thread exits. You may check to see if BeginAccepting succeeds by waiting a short time (perhaps 50 millisec) and then examine the IsAccepting property. If it is False, then BeginAccepting failed.

Returns True for success, False for failure.

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BeginAcceptingAsync (1)
Function BeginAcceptingAsync(listenPort As Int32) As Chilkat.Task

Creates an asynchronous task to call the BeginAccepting method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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CloseTunnel
Function CloseTunnel(waitForThreads As Boolean) As Boolean
Introduced in version 9.5.0.50

Closes the SSH tunnel and disconnects all existing clients. If waitForThreads is True, the method will wait for the tunnel and client threads to exit before returning.

Returns True for success, False for failure.

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Connect
Function Connect(hostname As String, port As Int32) As Boolean
Introduced in version 9.5.0.50

Connects to the SSH server to be used for SSH tunneling.

Returns True for success, False for failure.

More Information and Examples
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ConnectAsync (1)
Function ConnectAsync(hostname As String, port As Int32) As Chilkat.Task
Introduced in version 9.5.0.50

Creates an asynchronous task to call the Connect method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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ConnectThroughSsh
Function ConnectThroughSsh(ssh As Chilkat.Ssh, hostname As String, port As Int32) As Boolean
Introduced in version 9.5.0.55

Connects to an SSH server through an existing SSH connection. The ssh is an existing connected and authenticated SSH object. The connection to hostname:port is made through the existing SSH connection via port-forwarding. If successful, the connection is as follows: application => ServerSSH1 => ServerSSH2. (where ServerSSH1 is the ssh and ServerSSH2 is the SSH server at hostname:port) Once connected in this way, all communications are routed through ServerSSH1 to ServerSSH2. This includes authentication -- which means the application must still call one of the Authenticate* methods to authenticate with ServerSSH2.

Returns True for success, False for failure.

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ConnectThroughSshAsync (1)
Function ConnectThroughSshAsync(ssh As Chilkat.Ssh, hostname As String, port As Int32) As Chilkat.Task
Introduced in version 9.5.0.55

Creates an asynchronous task to call the ConnectThroughSsh method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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DisconnectAllClients
Function DisconnectAllClients(waitForThreads As Boolean) As Boolean
Introduced in version 9.5.0.50

Disconnects all clients, keeping the SSH tunnel open. If waitForThreads is True, the method will wait for the client threads to exit before returning.

Returns True for success, False for failure.

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GetCurrentState
Function GetCurrentState() As String
Introduced in version 9.5.0.65

Returns the current state of existing tunnels in an XML string.

Returns Nil on failure

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IsSshConnected
Function IsSshConnected() As Boolean
Introduced in version 9.5.0.61

Returns True if connected to the SSH server. Returns False if the connection has been lost (or was never established).

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SaveLastError
Function SaveLastError(path As String) As Boolean

Saves the last-error information (the contents of LastErrorXml) to an XML formatted file.

Returns True for success, False for failure.

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StopAccepting
Function StopAccepting(waitForThread As Boolean) As Boolean

Stops the listen background thread. It is possible to continue accepting connections by re-calling BeginAccepting. If waitForThread is True, the method will wait for the listen thread to exit before returning.

Returns True for success, False for failure.

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UnlockComponent
Function UnlockComponent(unlockCode As String) As Boolean

Unlocks the component. This must be called once prior to calling any other method. A fully-functional 30-day trial is automatically started when an arbitrary string is passed to this method. For example, passing "Hello", or "abc123" will unlock the component for the 1st thirty days after the initial install.

Returns True for success, False for failure.

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Events

To implement events, your application would define and implement a class that is a subclass of Chilkat.SshTunnel. Your custom class would implement (i.e. override) some or all of the event methods.

For example:

class MySshTunnel
    Inherits Chilkat.SshTunnel

    Function AbortCheck() As Boolean

    Sub BinaryData(data As MemoryBlock)

    Function PercentDone(pctDone As Int32) As Boolean

    Sub ProgressInfo(name As String, value As String)

    Sub TaskCompleted(task As Chilkat.Task)

    Sub TextData(data As String)


End Class
AbortCheck
Function AbortCheck() As Boolean

Provides the opportunity for a method call to be aborted. The AbortCheck event is fired periodically based on the value of the HeartbeatMs property. If HeartbeatMs is 0, then no AbortCheck events will fire. As an example, to fire 5 AbortCheck events per second, set the HeartbeatMs property equal to 200.

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PercentDone
Function PercentDone(pctDone As Int32) As Boolean

Provides the percentage completed for any method that involves network communications or time-consuming processing (assuming it is a method where a percentage completion can be measured). This event is only fired when it is possible to know a percentage completion, and when it makes sense to express the operation as a percentage completed. The pctDone argument will have a value from 1 to 100. For operations (Chilkat method calls) that complete very quickly, the number of PercentDone callbacks will vary, but the final callback should have a value of 100. For long running operations, no more than one callback per percentage point will occur (for example: 1, 2, 3, ... 98, 99, 100).

The PercentDone callback counts as an AbortCheck event. For method calls that complete quickly such that PercentDone events fire, it may be that AbortCheck events don't fire because the opportunity to abort is already provided in the PercentDone callback. For time consuming operations, where the amount of time between PercentDone callbacks are long, AbortCheck callbacks may be used to allow for the operation to be aborted in a more responsive manner.

The abort output argument provides a means for aborting the operation. Setting it to True will cause the method to abort and return a failed status (or whatever return value indicates failure).

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ProgressInfo
Sub ProgressInfo(name As String, value As String)

A general name/value event that provides information about what is happening during a method call. To find out what information is available, write code to handle this event and log the name/value pairs. Most are self-explanatory.

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TaskCompleted
Sub TaskCompleted(task As Chilkat.Task)

Called in the background thread when an asynchronous task completes.

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