(MFC) 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.

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

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

void ChilkatSample(void)
    {
    CkString strOut;

    // 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
    bool success = pdf.LoadFile("qa_data/pdf/hello.pdf");
    if (success == false) {
        strOut.append(pdf.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        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) {
        strOut.append(cert.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Tell the pdf object to use the certificate for signing.
    success = pdf.SetSigningCert(cert);
    if (success == false) {
        strOut.append(pdf.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    success = pdf.SignPdf(json,"qa_output/hello_signed.pdf");
    if (success == false) {
        strOut.append(pdf.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    strOut.append("PDF successfully signed with an invisible signature.");
    strOut.append("\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:
    


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }