Sign PDF with Invisible Signature

See more PDF Signatures Examples

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

var success = false;

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

var 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) {
    console.log(pdf.LastErrorText);
    return;
}

// Options for signing are specified in JSON.
var 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.)
var cert = new CkCert();
success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","secret");
if (success == false) {
    console.log(cert.LastErrorText);
    return;
}

// Tell the pdf object to use the certificate for signing.
success = pdf.SetSigningCert(cert);
if (success == false) {
    console.log(pdf.LastErrorText);
    return;
}

success = pdf.SignPdf(json,"qa_output/hello_signed.pdf");
if (success == false) {
    console.log(pdf.LastErrorText);
    return;
}

console.log("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)