PHP Extension

CoSign PKCS7/CMS Signed Data

See more Digital Signatures Examples

Demonstrates how to add a 2nd signature to a CMS SignedData. This is to add an additional signature, SignerInfo and certificate(s) to an existing CMS signed data.

In this example, we cosign an existing pdf.p7s

Note: The CoSign method is added in Chilkat v9.5.0.89.

PHP Extension

<?php

include("chilkat.php");

$success = false;

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

$crypt = new CkCrypt2();
$cert = new CkCert();

// If loading from a smart card, set the smartcard PIN.
$cert->put_SmartCardPin('0000');

// Load a certificate in some way, such as from a smart card.
// Chilkat provides other methods to load from a .pfx, .pem, or from the Windows certificate stores..
$success = $cert->LoadFromSmartcard('');
if ($success == false) {
    print $cert->lastErrorText() . "\n";
    exit;
}

$success = $crypt->SetSigningCert($cert);
if ($success == false) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

// Load the file to be co-signed.
// NOTE:  This is to cosign a PDF file contained within a CMS (PKCS7) message.
// (In other words, the PDF is contained within the CMS SignedData, rather than the other way around
// where a CMS signature is contained within a PDF.  Use Chilkat's PDF class to sign a PDF, which is
// to embed a CMS signature within the PDF.)
$bd = new CkBinData();
$success = $bd->LoadFile('qa_data/p7s/cosign/sample.pdf.p7s');
if ($success == false) {
    print 'Failed to load pdf.p7s input file.' . "\n";
    exit;
}

// bd2 will contain the co-signed result.
$bd2 = new CkBinData();
$success = $crypt->CoSign($bd,$cert,$bd2);
if ($success == false) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

$success = $bd->WriteFile('qa_output/cosigned.pdf.p7s');
if ($success == false) {
    print 'Failed to save pdf.p7s output file.' . "\n";
    exit;
}

print 'Success!' . "\n";

?>