Visual FoxPro

Connect to an SSH Server Through Another (Jump Host)

Demonstrates the Chilkat Ssh.ConnectThroughSsh method, which connects to a second SSH server through an already connected and authenticated Ssh object. The first argument is the first (jump-host) Ssh object, and the second and third are the destination hostname and port.

Background: This is SSH chaining through a "jump host" (bastion): the application connects to a reachable gateway, then tunnels onward to a target that is only accessible from inside the network. Each hop is authenticated separately with its own credentials. The result is a normal Ssh object for the target that happens to be routed through the first connection.

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LOCAL lnSuccess
LOCAL loSshJump
LOCAL lnSshPort
LOCAL lcPassword
LOCAL loSshTarget

lnSuccess = 0

*  Demonstrates the Ssh.ConnectThroughSsh method, which connects to a second SSH server through
*  an already connected and authenticated Ssh object (a jump host).  The 1st argument is the
*  first Ssh object, and the 2nd and 3rd are the destination hostname and port.

loSshJump = CreateObject('Chilkat.Ssh')

*  Connect and authenticate to the first SSH server (the jump host).
lnSshPort = 22
lnSuccess = loSshJump.Connect("jump.example.com",lnSshPort)
IF (lnSuccess = 0) THEN
    ? loSshJump.LastErrorText
    RELEASE loSshJump
    CANCEL
ENDIF

*  Normally you would not hard-code the password in source.  You should instead obtain it
*  from an interactive prompt, environment variable, or a secrets vault.
lcPassword = "mySshPassword"

lnSuccess = loSshJump.AuthenticatePw("jumpUser",lcPassword)
IF (lnSuccess = 0) THEN
    ? loSshJump.LastErrorText
    RELEASE loSshJump
    CANCEL
ENDIF

*  Connect to the target SSH server through the jump host.
loSshTarget = CreateObject('Chilkat.Ssh')
lnSuccess = loSshTarget.ConnectThroughSsh(loSshJump,"target.example.com",lnSshPort)
IF (lnSuccess = 0) THEN
    ? loSshTarget.LastErrorText
    RELEASE loSshJump
    RELEASE loSshTarget
    CANCEL
ENDIF

*  Authenticate to the target server (separate credentials).
lnSuccess = loSshTarget.AuthenticatePw("targetUser",lcPassword)
IF (lnSuccess = 0) THEN
    ? loSshTarget.LastErrorText
    RELEASE loSshJump
    RELEASE loSshTarget
    CANCEL
ENDIF

? "Connected to the target through the jump host."

loSshTarget.Disconnect()
loSshJump.Disconnect()

RELEASE loSshJump
RELEASE loSshTarget