(Android™) Sign PDF in the Cloud using AWS CloudHSM

See more Signing in the Cloud Examples

Demonstrates how to sign a PDF using AWS CloudHSM. The signing of the hash happens on a hardware token in AWS CloudHSM. Everything else involving the updating the PDF to add the signature happens locally within Chilkat.

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

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// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // 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.

    CkPkcs11 pkcs11 = new CkPkcs11();

    // Provide the path to the AWS CloudHSM PKCS11 driver.
    // This example runs on Windows, so we'll provide the CloudHSM DLL.
    // If your code runs on Linux, the CloudHSM driver might be at /opt/cloudhsm/lib/libcloudhsm_pkcs11.so
    pkcs11.put_SharedLibPath("C:\\Program Files\\Amazon\\CloudHSM\\lib\\cloudhsm_pkcs11.dll");

    // Your PIN should be a string containing your crypto user's login and password, with a colon char delimiting.
    // See https://docs.aws.amazon.com/cloudhsm/latest/userguide/pkcs11-pin.html
    String pin = "user:password";
    int userType = 1;

    // Establish a PKCS logged-on session using the driver (.so, .dylib, or .dll) as specified in the SharedLibPath above.
    boolean success = pkcs11.QuickSession(userType,pin);
    if (success == false) {
        Log.i(TAG, pkcs11.lastErrorText());
        return;
        }

    CkCert cert = new CkCert();
    success = cert.LoadFromFile("qa_data/certs/myCert.cer");
    if (success == false) {
        Log.i(TAG, cert.lastErrorText());
        return;
        }

    // Tell the certificate to link with the PKCS11 session.
    // The cert's private key should be installed on the CloudHSM.
    // If there are multiple private keys on the CloudHSM, then Chilkat will automatically
    // locate and use the private key corresponding to the certificate.
    success = cert.LinkPkcs11(pkcs11);
    if (success == false) {
        Log.i(TAG, cert.lastErrorText());
        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..

    CkPdf pdf = new CkPdf();

    // Load a PDF to be signed.
    success = pdf.LoadFile("qa_data/pdf/hello.pdf");
    if (success == false) {
        Log.i(TAG, pdf.lastErrorText());
        success = pkcs11.CloseSession();
        return;
        }

    CkJsonObject json = new 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");

    int i = 0;
    json.put_I(i);
    json.UpdateString("appearance.text[i]","Digitaly signed by: Xyz Widgets, Inc.");
    i = i + 1;
    json.put_I(i);
    json.UpdateString("appearance.text[i]","current_dt");
    i = i + 1;
    json.put_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.
    success = pdf.SetSigningCert(cert);

    success = pdf.SignPdf(json,"qa_output/out.pdf");
    if (success == false) {
        Log.i(TAG, pdf.lastErrorText());
        success = pkcs11.CloseSession();
        return;
        }

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

    // Revert to an unauthenticated session by calling Logout.
    success = pkcs11.Logout();
    if (success == false) {
        Log.i(TAG, pkcs11.lastErrorText());
        success = 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).
    success = pkcs11.CloseSession();
    if (success == false) {
        Log.i(TAG, pkcs11.lastErrorText());
        return;
        }

    Log.i(TAG, "Success.");

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}