Pascal (Lazarus/Delphi)

SSH Public Key Authentication

Demonstrates authenticating with an SSH server using public-key authentication. A private key is loaded into an SshKey object and passed to AuthenticatePk. The matching public key must already be installed on the server for the account.

Note: The private-key path is relative to the application's current working directory. Supply the path to your own key file.

Background: Public-key authentication is the standard for unattended and automated SSH: the private key never leaves the client, the server merely trusts the corresponding public key, and no reusable password crosses the wire. SshKey imports several formats — OpenSSH PEM keys via FromOpenSshPrivateKey and PuTTY .ppk files via FromPuttyPrivateKey — encrypted or not. For an encrypted key, set the Password property before importing. Note that LoadText is only a convenience for reading a text file into a string; it does not itself load the key.

Chilkat Pascal (Lazarus/Delphi) Downloads

Download Chilkat for Pascal (Lazarus/Delphi)

Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Ssh,
  Chilkat.SshKey;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  ssh: TSsh;
  hostname: string;
  port: Integer;
  key: TSshKey;
  privKeyText: string;

begin
  success := False;

  //  This example requires the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  //  Demonstrates authenticating with an SSH server using public-key authentication.  The matching
  //  public key must already be installed on the SSH server for the account.

  ssh := TSsh.Create;

  //  Timeouts, in milliseconds.
  ssh.ConnectTimeoutMs := 5000;
  ssh.ReadTimeoutMs := 15000;

  hostname := 'ssh.example.com';
  port := 22;
  success := ssh.Connect(hostname,port);
  if (success = False) then
    begin
      WriteLn(ssh.LastErrorText);
      Exit;
    end;

  //  LoadText is a convenience method that reads any text file into a string.  It does not itself
  //  load the key.
  key := TSshKey.Create;
  privKeyText := key.LoadText('qa_data/my_private_key.pem');
  if (key.LastMethodSuccess = False) then
    begin
      WriteLn(key.LastErrorText);
      Exit;
    end;

  //  Import the private key.  Both OpenSSH and PuTTY formats are supported, encrypted or not.
  //  This example loads an unencrypted OpenSSH-format key; for a PuTTY .ppk file, call
  //  FromPuttyPrivateKey instead.  For an encrypted key, set key.Password before importing.
  success := key.FromOpenSshPrivateKey(privKeyText);
  if (success = False) then
    begin
      WriteLn(key.LastErrorText);
      Exit;
    end;

  success := ssh.AuthenticatePk('mySshLogin',key);
  if (success = False) then
    begin
      WriteLn(ssh.LastErrorText);
      Exit;
    end;

  WriteLn('Public-key authentication successful.');

  ssh.Disconnect();


  ssh.Free;
  key.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.