(PureBasic) Multi-Hop SSH (SSH Through SSH)

Demonstrates how to SSH through one SSH server to get to another SSH server. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2

The ConnectThroughSsh method is added in Chilkat version 9.5.0.55 to accomplish this task. Technically, it should be possible to chain any number of servers using the ConnectThroughSsh multiple times:

Application => ServerSSH1 => ServerSSH2 ==> ServerSSH3 => ... => ServerSSHN

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkSsh.pb"

Procedure ChilkatExample()

    ; This example assumes the Chilkat API to have been previously unlocked.
    ; See Global Unlock Sample for sample code.

    ssh1.i = CkSsh::ckCreate()
    If ssh1.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Hostname may be an IP address or domain name:
    hostname.s = "192.168.1.108"
    port.s = 22

    ; Connect directly to the 1st SSH server:
    success.i = CkSsh::ckConnect(ssh1,hostname,port)
    If success <> 1
        Debug CkSsh::ckLastErrorText(ssh1)
        CkSsh::ckDispose(ssh1)
        ProcedureReturn
    EndIf

    ; Wait a max of 15 seconds when reading responses..
    CkSsh::setCkIdleTimeoutMs(ssh1, 15000)

    ; Authenticate using login/password:
    success = CkSsh::ckAuthenticatePw(ssh1,"myLogin","myPassword")
    If success <> 1
        Debug CkSsh::ckLastErrorText(ssh1)
        CkSsh::ckDispose(ssh1)
        ProcedureReturn
    EndIf

    ; Connect through the 1st SSH connection to reach a 2nd SSH server.
    ; Note: Any number of SSH connections may be simultaneously tunneled through a single
    ; existing SSH connection.
    ssh2.i = CkSsh::ckCreate()
    If ssh2.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkSsh::ckConnectThroughSsh(ssh2,ssh1,"someremoteserver.com",22)
    If success <> 1
        Debug CkSsh::ckLastErrorText(ssh2)
        CkSsh::ckDispose(ssh1)
        CkSsh::ckDispose(ssh2)
        ProcedureReturn
    EndIf

    CkSsh::setCkIdleTimeoutMs(ssh2, 15000)

    ; Authenticate with ssh2...
    success = CkSsh::ckAuthenticatePw(ssh2,"myLogin2","myPassword2")
    If success <> 1
        Debug CkSsh::ckLastErrorText(ssh2)
        CkSsh::ckDispose(ssh1)
        CkSsh::ckDispose(ssh2)
        ProcedureReturn
    EndIf

    ; The application may now is connected and authenticated with ssh2.
    ; The application can do whatever it desires just as if it was directly
    ; connected to ssh2.   For example, the application might open
    ; a session channel to send commands or start a remote shell..
    channelNum.i = CkSsh::ckOpenSessionChannel(ssh2)
    If channelNum < 0
        Debug CkSsh::ckLastErrorText(ssh2)
        CkSsh::ckDispose(ssh1)
        CkSsh::ckDispose(ssh2)
        ProcedureReturn
    EndIf

    ; ...
    ; ...
    ; ...

    ; Close the connection with ssh2.  (This closes the the tunnel through ssh1.)
    ; The connection with ssh1 is still alive, and may be used for more connections.
    CkSsh::ckDisconnect(ssh2)

    ; ...
    ; ...
    ; ...

    CkSsh::ckDisconnect(ssh1)


    CkSsh::ckDispose(ssh1)
    CkSsh::ckDispose(ssh2)


    ProcedureReturn
EndProcedure