Java

Sign PDF with Invisible Signature

See more PDF Signatures Examples

Demonstrates how to sign a PDF with an invisible signature.

Note: This example requires Chilkat v9.5.0.85 or greater.

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.

    CkPdf pdf = new CkPdf();

    //  Load a PDF to be signed.
    //  The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
    success = pdf.LoadFile("qa_data/pdf/hello.pdf");
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    //  Options for signing are specified in JSON.
    CkJsonObject json = new CkJsonObject();

    //  In most cases, the signingCertificateV2 and signingTime attributes are required.
    json.UpdateInt("signingCertificateV2",1);
    json.UpdateInt("signingTime",1);

    //  Indicate that the signature will be invisible.
    json.UpdateBool("invisibleSignature",true);

    //  Load the signing certificate. (Use your own certificate.)
    CkCert cert = new CkCert();
    success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","secret");
    if (success == false) {
        System.out.println(cert.lastErrorText());
        return;
        }

    //  Tell the pdf object to use the certificate for signing.
    success = pdf.SetSigningCert(cert);
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    success = pdf.SignPdf(json,"qa_output/hello_signed.pdf");
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    System.out.println("PDF successfully signed with an invisible signature.");

    //  An invisible signature has no appearance within the PDF document itself,
    //  but Adobe Acrobat will indicate the document is signed in a toolbar, as shown here:
    //  (image:https://example-code.com/images/invisible_signature.jpg/endImage)
  }
}