Swift

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.

Chilkat Swift Downloads

Download Chilkat for Swift

Swift


func chilkatTest() {
    var success: Bool = 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.

    let sshJump = CkoSsh()!

    //  Connect and authenticate to the first SSH server (the jump host).
    var sshPort: Int = 22
    success = sshJump.connect(hostname: "jump.example.com", port: sshPort)
    if success == false {
        print("\(sshJump.lastErrorText!)")
        return
    }

    //  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.
    var password: String? = "mySshPassword"

    success = sshJump.authenticatePw(login: "jumpUser", password: password)
    if success == false {
        print("\(sshJump.lastErrorText!)")
        return
    }

    //  Connect to the target SSH server through the jump host.
    let sshTarget = CkoSsh()!
    success = sshTarget.connect(throughSsh: sshJump, hostname: "target.example.com", port: sshPort)
    if success == false {
        print("\(sshTarget.lastErrorText!)")
        return
    }

    //  Authenticate to the target server (separate credentials).
    success = sshTarget.authenticatePw(login: "targetUser", password: password)
    if success == false {
        print("\(sshTarget.lastErrorText!)")
        return
    }

    print("Connected to the target through the jump host.")

    sshTarget.disconnect()
    sshJump.disconnect()

}