Delphi DLL

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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var
success: Boolean;
sshJump: HCkSsh;
sshPort: Integer;
password: PWideChar;
sshTarget: HCkSsh;

begin
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 := CkSsh_Create();

//  Connect and authenticate to the first SSH server (the jump host).
sshPort := 22;
success := CkSsh_Connect(sshJump,'jump.example.com',sshPort);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(sshJump));
    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 := CkSsh_AuthenticatePw(sshJump,'jumpUser',password);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(sshJump));
    Exit;
  end;

//  Connect to the target SSH server through the jump host.
sshTarget := CkSsh_Create();
success := CkSsh_ConnectThroughSsh(sshTarget,sshJump,'target.example.com',sshPort);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(sshTarget));
    Exit;
  end;

//  Authenticate to the target server (separate credentials).
success := CkSsh_AuthenticatePw(sshTarget,'targetUser',password);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSsh__lastErrorText(sshTarget));
    Exit;
  end;
Memo1.Lines.Add('Connected to the target through the jump host.');

CkSsh_Disconnect(sshTarget);
CkSsh_Disconnect(sshJump);

CkSsh_Dispose(sshJump);
CkSsh_Dispose(sshTarget);