Dart

PKCS11 Sign PDF using Certificate and Private Key on Smart Card / USB Token

See more PKCS11 Examples

Sample code showing how to use PKCS11 to sign a PDF with a certificate and private key stored on a smart card or USB token.

Note: This example requires Chilkat v9.5.0.96 or later.

Dart

import 'package:chilkat/chilkat.dart';

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

  // Note: Chilkat's PKCS11 implementation runs on Windows, Linux, Mac OS X, and other supported operating systems.

  final pkcs11 = CkPkcs11();

  pkcs11.sharedLibPath = 'C:/Program Files (x86)/Gemalto/IDGo 800 PKCS#11/IDPrimePKCS1164.dll';
  final pin = '0000';
  final userType = 1;

  // Establish a PKCS11 logged-on session using the driver (.so, .dylib, or .dll) as specified in the SharedLibPath above.
  try {
    pkcs11.quickSession(userType, pin);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Get the certificate (on the smart card) that has a private key.
  // There are other ways to locate a certificate on the HSM.
  // This example assumes there is a single certificate w/ private key.
  final cert = CkCert();
  try {
    pkcs11.findCert('privateKey', '', cert);
    print('Cert with private key: ${cert.subjectCN}');
  } on ChilkatException {
    print('No certificates having a private key were found.');
    pkcs11.closeSession();
    return;
  }

  // --------------------------------------------------------------------------
  // At this point, we have the cert to be used for signing.
  // Our PDF signing code is the same as for a cert obtained from any other source..

  final pdf = CkPdf();

  // Load a PDF to be signed.
  try {
    pdf.loadFile('qa_data/pdf/hello.pdf');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    pkcs11.closeSession();
    return;
  }

  final json = CkJsonObject();

  json.updateInt('page', 1);
  json.updateString('appearance.y', 'top');
  json.updateString('appearance.x', 'left');
  json.updateString('appearance.fontScale', '10.0');
  json.updateString('signingAlgorithm', 'pss');
  json.updateString('hashAlgorithm', 'sha256');

  var i = 0;
  json.i = i;
  json.updateString('appearance.text[i]', 'Digitaly signed by: Xyz Widgets, Inc.');
  i++;
  json.i = i;
  json.updateString('appearance.text[i]', 'current_dt');
  i++;
  json.i = i;
  json.updateString('appearance.text[i]', 'blah blah blah');

  // The certificate is internally linked to the Pkcs11 object, which is currently in an authenticated session.
  pdf.setSigningCert(cert);

  try {
    pdf.signPdf(json, 'qa_output/out.pdf');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    pkcs11.closeSession();
    return;
  }

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

  // Revert to an unauthenticated session by calling Logout.
  try {
    pkcs11.logout();
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    pkcs11.closeSession();
    return;
  }

  // When finished, close the session.
  // It is important to close the session (memory leaks will occur if the session is not properly closed).
  try {
    pkcs11.closeSession();
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Success.');
}