Delphi ActiveX

SSH HSM Public Key Authentication

Demonstrates SSH public-key authentication using a private key stored on an HSM — a USB token or smart card — accessed through PKCS#11. A session is opened with the vendor's driver, the key handles are located, and an SshKey object is bound to them with UsePkcs11.

Background: The point of an HSM is that the private key is generated on the device and cannot be exported: the signing operation happens on the hardware, so the key material never reaches your application's memory or disk. Even a fully compromised host cannot yield a copy of the key. PKCS#11 is the vendor-neutral interface to such devices, which is why the driver path and the object-finding template are the only vendor-specific parts of this example.

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var
success: Integer;
pkcs11: TChilkatPkcs11;
pin: WideString;
userType: Integer;
json: TChilkatJsonObject;
priv_handle: Cardinal;
pub_handle: Cardinal;
key: TChilkatSshKey;
keyType: WideString;
ssh: TChilkatSsh;
port: Integer;

begin
success := 0;

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

//  Demonstrates SSH public-key authentication using a private key stored on an HSM (a USB token
//  or smart card) accessed through PKCS#11.
//  
//  Note: Chilkat's PKCS#11 implementation runs on Windows, Linux, macOS, and other supported
//  operating systems.

pkcs11 := TChilkatPkcs11.Create(Self);

//  The PKCS#11 driver supplied by your HSM vendor: a .dll on Windows, a .so on Linux, or a
//  .dylib on macOS.
pkcs11.SharedLibPath := 'C:/Program Files (x86)/Gemalto/IDGo 800 PKCS#11/IDPrimePKCS1164.dll';

//  The PIN should come from a secure source rather than being hard-coded.
pin := '0000';

//  Normal user = 1
userType := 1;

success := pkcs11.QuickSession(userType,pin);
if (success = 0) then
  begin
    Memo1.Lines.Add(pkcs11.LastErrorText);
    Exit;
  end;

//  Describe the private key object to be located on the HSM.
json := TChilkatJsonObject.Create(Self);
json.UpdateString('class','private_key');
json.UpdateString('label','MySshKey');

priv_handle := pkcs11.FindObject(json.ControlInterface);
if (priv_handle = 0) then
  begin
    Memo1.Lines.Add(pkcs11.LastErrorText);
    Exit;
  end;

//  Find the corresponding public key by changing the class in the same template.
json.UpdateString('class','public_key');

pub_handle := pkcs11.FindObject(json.ControlInterface);
if (pub_handle = 0) then
  begin
    Memo1.Lines.Add(pkcs11.LastErrorText);
    Exit;
  end;

//  Create an SSH key object that uses the HSM handles.  The key type may be "rsa" or "ec".
key := TChilkatSshKey.Create(Self);
keyType := 'rsa';
success := key.UsePkcs11(pkcs11.ControlInterface,priv_handle,pub_handle,keyType);
if (success = 0) then
  begin
    Memo1.Lines.Add(key.LastErrorText);
    Exit;
  end;

ssh := TChilkatSsh.Create(Self);

port := 22;
success := ssh.Connect('ssh.example.com',port);
if (success = 0) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

//  The corresponding public key must already be installed on the SSH server for the account.
//  The signing operation happens on the HSM -- the private key never leaves the device.
success := ssh.AuthenticatePk('mySshLogin',key.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(ssh.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('Public-key authentication successful.');

ssh.Disconnect();

pkcs11.Logout();
pkcs11.CloseSession();