(PHP Extension) Get PDF Signer Certs

See more PDF Signatures Examples

This example demonstrates how to validate the signatures in a PDF and also shows how to get each signature's signer certificate.

Note: This example requires Chilkat v9.5.0.87 or greater.

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<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

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

$pdf = new CkPdf();

// Load a PDF that has cryptographic signatures to be validated
$success = $pdf->LoadFile('qa_data/pdf/sign_testing_1/helloSigned2.pdf');
if ($success == false) {
    print $pdf->lastErrorText() . "\n";
    exit;
}

// Each time we verify a signature, information about the signature is written into
// sigInfo (replacing whatever sigInfo previously contained).
$sigInfo = new CkJsonObject();

// Iterate over each signature and validate each.
$numSignatures = $pdf->get_NumSignatures();
$validated = false;
$cert = new CkCert();
$i = 0;
while ($i < $numSignatures) {
    $validated = $pdf->VerifySignature($i,$sigInfo);
    print 'Signature ' . $i . ' validated: ' . $validated . "\n";

    // The GetSignerCert method was added in Chilkat v9.5.0.87
    // After calling VerifySignature, you can get the signer certificate by calling
    // GetSignerCert with the same index. 
    $success = $pdf->GetSignerCert($i,$cert);
    if ($success != false) {
        print 'PDF signer certificate: ' . $cert->subjectDN() . "\n";
    }

    $i = $i + 1;
}

print 'Finished.' . "\n";

?>