Ruby

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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Ruby

require 'chilkat'

success = false

#  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.

sshJump = Chilkat::CkSsh.new()

#  Connect and authenticate to the first SSH server (the jump host).
sshPort = 22
success = sshJump.Connect("jump.example.com",sshPort)
if (success == false)
    print sshJump.lastErrorText() + "\n";
    exit
end

#  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.
password = "mySshPassword"

success = sshJump.AuthenticatePw("jumpUser",password)
if (success == false)
    print sshJump.lastErrorText() + "\n";
    exit
end

#  Connect to the target SSH server through the jump host.
sshTarget = Chilkat::CkSsh.new()
success = sshTarget.ConnectThroughSsh(sshJump,"target.example.com",sshPort)
if (success == false)
    print sshTarget.lastErrorText() + "\n";
    exit
end

#  Authenticate to the target server (separate credentials).
success = sshTarget.AuthenticatePw("targetUser",password)
if (success == false)
    print sshTarget.lastErrorText() + "\n";
    exit
end

print "Connected to the target through the jump host." + "\n";

sshTarget.Disconnect()
sshJump.Disconnect()