PHP ActiveX

PDF Sign Unsigned Signature Field

See more PDF Signatures Examples

Demonstrates how to sign a PDF's unsigned signature field.

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

PHP ActiveX

<?php

$success = 0;

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

$pdf = new COM("Chilkat.Pdf");

//  Load a PDF containing an unsigned signature field.
$success = $pdf->LoadFile('qa_data/pdf/unsigned_sig_field/due_diligence.pdf');
if ($success == 0) {
    print $pdf->LastErrorText . "\n";
    exit;
}

//  A PDF with an unsigned signature field appears in Adobe Acrobat as shown below.
//  (When the mouse pointer is hovered over the field, a tooltip will likely show a message
//  such as "Unsigned signature field (Click to sign)".  
//  This example code will automatically find the unsigned signature field,
//  and signs using your certificate.  It automatically sizes the text to the space alotted
//  for the signature.
//  

//  Options for signing are specified in JSON.
$json = new COM("Chilkat.JsonObject");

//  In most cases, the signingCertificateV2 and signingTime attributes are required.
$json->UpdateInt('signingCertificateV2',1);
$json->UpdateInt('signingTime',1);

//  We don't specify the page or a specific location because Chilkat will automatically
//  find the unsigned signature field and use its location and size and will scale the
//  signatures visual appearance (text + graphics) to the correct size required to fit.
//  We only need to indicate the desire to fill the unsigned signature field.
$json->UpdateBool('appearance.fillUnsignedSignatureField',1);

//  Starting in Chilkat v9.5.0.90, if a PDF contains multiple unsigned signature fields,
//  the field to be signed can be chosen by name:
//  To list unsigned signature fields, see this example: List PDF Unsigned Signature Fields
$json->UpdateString('unsignedSignatureField','doctor_signature');

//  Note: If the PDF document contains multiple unsigned signature fields, Chilkat will 
//  sign the 1st one found. 

//  In this example, the appearance of the digital signature will contain three lines:
//  1) The signing certificate's common name
//  2) The current date/time
//  3) Some arbitrary text.
//  The keyword "cert_cn" is replaced with the Certificate's Subject Common Name.
//  The keyword "current_dt" is replaced with the current date/time.
//  Any number of appearance text lines can be added.
$json->UpdateString('appearance.text[0]','Digitally signed by: cert_cn');
$json->UpdateString('appearance.text[1]','current_dt');
$json->UpdateString('appearance.text[2]','The crazy brown fox jumps over the lazy dog.');

//  This signature will include one of the built-in SVG graphics (green-check-grey-circle).
$json->UpdateString('appearance.image','green-check-grey-circle');
$json->UpdateString('appearance.imagePlacement','left');

//  Load the signing certificate. (Use your own certificate.)
$cert = new COM("Chilkat.Cert");
$success = $cert->LoadPfxFile('qa_data/pfx/myPdfSigningCert.pfx','secret');
if ($success == 0) {
    print $cert->LastErrorText . "\n";
    exit;
}

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

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

print 'The PDF has been successfully cryptographically signed.' . "\n";

//  The appearance of the signature appears in Adobe Acrobat as shown below.
//  

?>