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.

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import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.JsonObject;
import com.chilkatsoft.chilkat2.Pkcs11;
import com.chilkatsoft.chilkat2.Ssh;
import com.chilkatsoft.chilkat2.SshKey;

public class ChilkatExample {

    public static void main(String[] args) {
        // 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 pkcs11 = new Pkcs11();

        // The PKCS#11 driver supplied by your HSM vendor: a .dll on Windows, a .so on Linux, or a
        // .dylib on macOS.
        pkcs11.setSharedLibPath("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;

        try {
            pkcs11.quickSession(userType, pin);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

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

        long priv_handle = pkcs11.findObject(json);
        if (priv_handle == 0) {
            System.out.println(pkcs11.getLastErrorText());
            return;
        }

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

        long pub_handle = pkcs11.findObject(json);
        if (pub_handle == 0) {
            System.out.println(pkcs11.getLastErrorText());
            return;
        }

        // Create an SSH key object that uses the HSM handles.  The key type may be "rsa" or "ec".
        SshKey key = new SshKey();
        String keyType = "rsa";
        try {
            key.usePkcs11(pkcs11, priv_handle, pub_handle, keyType);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        Ssh ssh = new Ssh();

        int port = 22;
        try {
            ssh.connect("ssh.example.com", port);

            // 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.
            ssh.authenticatePk("mySshLogin", key);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

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

        ssh.disconnect();

        pkcs11.logout();
        pkcs11.closeSession();
    }
}