Java

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.

Chilkat Java Downloads

Download Chilkat for Java

Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    //  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.

    CkPkcs11 pkcs11 = new CkPkcs11();

    //  The PKCS#11 driver supplied by your HSM vendor: a .dll on Windows, a .so on Linux, or a
    //  .dylib on macOS.
    pkcs11.put_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.
    String pin = "0000";

    //  Normal user = 1
    int userType = 1;

    success = pkcs11.QuickSession(userType,pin);
    if (success == false) {
        System.out.println(pkcs11.lastErrorText());
        return;
        }

    //  Describe the private key object to be located on the HSM.
    CkJsonObject json = new CkJsonObject();
    json.UpdateString("class","private_key");
    json.UpdateString("label","MySshKey");

    int priv_handle = pkcs11.FindObject(json);
    if (priv_handle == 0) {
        System.out.println(pkcs11.lastErrorText());
        return;
        }

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

    int pub_handle = pkcs11.FindObject(json);
    if (pub_handle == 0) {
        System.out.println(pkcs11.lastErrorText());
        return;
        }

    //  Create an SSH key object that uses the HSM handles.  The key type may be "rsa" or "ec".
    CkSshKey key = new CkSshKey();
    String keyType = "rsa";
    success = key.UsePkcs11(pkcs11,priv_handle,pub_handle,keyType);
    if (success == false) {
        System.out.println(key.lastErrorText());
        return;
        }

    CkSsh ssh = new CkSsh();

    int port = 22;
    success = ssh.Connect("ssh.example.com",port);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    //  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);
    if (success == false) {
        System.out.println(ssh.lastErrorText());
        return;
        }

    System.out.println("Public-key authentication successful.");

    ssh.Disconnect();

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