(PHP Extension) Sign a Byte Array to Create an Opaque Signature in a Byte Array

Signs data contained in a byte array to produce an opaque signature (also in a byte array). An opaque signature is a PKCS7 signature (also known as CAdES) that embeds the signed data. Also shows how to verify the signature and extract the original data.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?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.

$cert = new CkCert();
$success = $cert->LoadPfxFile('qa_data/pfx/cert_test123.pfx','test123');
if ($success == false) {
    print $cert->lastErrorText() . "\n";
    exit;
}

$fac = new CkFileAccess();

$fileBytes = new CkByteData();
$success = $fac->ReadEntireFile('qa_data/pdf/sample.pdf',$fileBytes);
if ($fac->get_LastMethodSuccess() != true) {
    print $fac->lastErrorText() . "\n";
    exit;
}

$crypt = new CkCrypt2();

$success = $crypt->SetSigningCert($cert);

// We can sign any type of file.

$sigBytes = new CkByteData();
$success = $crypt->OpaqueSignBytes($fileBytes,$sigBytes);
if ($crypt->get_LastMethodSuccess() != true) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

$success = $fac->WriteEntireFile('qa_output/sample.pdf.p7m',$sigBytes);
if ($fac->get_LastMethodSuccess() != true) {
    print $fac->lastErrorText() . "\n";
    exit;
}

// We can verify the opaque signature and extract the original data like this
$originalData = new CkByteData();
$success = $crypt->OpaqueVerifyBytes($sigBytes,$originalData);
if ($crypt->get_LastMethodSuccess() != true) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

$success = $fac->WriteEntireFile('qa_output/sample.pdf',$originalData);
if ($fac->get_LastMethodSuccess() != true) {
    print $fac->lastErrorText() . "\n";
    exit;
}

print 'Signature is verified and the original data was extracted.' . "\n";

?>