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

Signs data contained in a byte array to produce a detached signature (also in a byte array). Also shows how to verify the signature.

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.
// The result is a detached signature (a signature that does not contain the data being signed).

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

$success = $fac->WriteEntireFile('qa_output/sample.pdf.p7s',$sigBytes);
if ($fac->get_LastMethodSuccess() != true) {
    print $fac->lastErrorText() . "\n";
    exit;
}

// We can verify the detached signature like this
$verified = $crypt->VerifyBytes($fileBytes,$sigBytes);
if ($crypt->get_LastMethodSuccess() != true) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

print 'Verified = ' . $verified . "\n";

?>