C++

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.

C++

#include <CkPdf.h>
#include <CkJsonObject.h>
#include <CkCert.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    CkPdf pdf;

    //  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) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    //  Options for signing are specified in JSON.
    CkJsonObject json;

    //  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;
    success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","secret");
    if (success == false) {
        std::cout << cert.lastErrorText() << "\r\n";
        return;
    }

    //  Tell the pdf object to use the certificate for signing.
    success = pdf.SetSigningCert(cert);
    if (success == false) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    success = pdf.SignPdf(json,"qa_output/hello_signed.pdf");
    if (success == false) {
        std::cout << pdf.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "PDF successfully signed with an invisible signature." << "\r\n";

    //  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)
    }