Perl

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.

Perl

use chilkat();

$success = 0;

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

$pdf = chilkat::CkPdf->new();

# 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 == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

# Options for signing are specified in JSON.
$json = chilkat::CkJsonObject->new();

# 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",1);

# Load the signing certificate. (Use your own certificate.)
$cert = chilkat::CkCert->new();
$success = $cert->LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","secret");
if ($success == 0) {
    print $cert->lastErrorText() . "\r\n";
    exit;
}

# Tell the pdf object to use the certificate for signing.
$success = $pdf->SetSigningCert($cert);
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

$success = $pdf->SignPdf($json,"qa_output/hello_signed.pdf");
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

print "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)