Delphi DLL

SSH Tunnel Authenticate with a SecureString Password

Demonstrates the Chilkat SshTunnel.AuthenticateSecPw method, which authenticates using SecureString login and password objects. The first argument is the login and the second is the password.

Background: Because a tunnel process is long-lived and holds its SSH credentials for its entire lifetime, protecting them in memory is worthwhile. A SecureString keeps the value encrypted under a randomly generated session key. Populate it from a value obtained at runtime rather than a hard-coded literal.

Chilkat Delphi DLL Downloads

Download Chilkat for Delphi DLL

Delphi DLL

var
success: Boolean;
tunnel: HCkSshTunnel;
sshPort: Integer;
password: PWideChar;
secureLogin: HCkSecureString;
securePassword: HCkSecureString;
waitForThreadExit: Boolean;

begin
success := False;

//  Demonstrates the SshTunnel.AuthenticateSecPw method, which authenticates using SecureString
//  login and password objects.  The 1st argument is the login and the 2nd is the password.

tunnel := CkSshTunnel_Create();

//  The tunnel forwards accepted local connections to this destination through the SSH server.
CkSshTunnel_putDestHostname(tunnel,'db.internal.example.com');
CkSshTunnel_putDestPort(tunnel,5432);

//  Connect to the SSH server.  This performs the TCP/proxy connection and SSH handshake, but
//  does not authenticate yet.
sshPort := 22;
success := CkSshTunnel_Connect(tunnel,'ssh.example.com',sshPort);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSshTunnel__lastErrorText(tunnel));
    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';

//  Place the login and password into SecureString objects.
secureLogin := CkSecureString_Create();
CkSecureString_Append(secureLogin,'mySshLogin');
securePassword := CkSecureString_Create();
CkSecureString_Append(securePassword,password);

success := CkSshTunnel_AuthenticateSecPw(tunnel,secureLogin,securePassword);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSshTunnel__lastErrorText(tunnel));
    Exit;
  end;
Memo1.Lines.Add('Authenticated with secure strings.');

//  After authenticating, call BeginAccepting to start listening for local connections to forward.

waitForThreadExit := True;
success := CkSshTunnel_CloseTunnel(tunnel,waitForThreadExit);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSshTunnel__lastErrorText(tunnel));
    Exit;
  end;

CkSshTunnel_Dispose(tunnel);
CkSecureString_Dispose(secureLogin);
CkSecureString_Dispose(securePassword);