Sign a File to Create a .p7s (Detached Signature)

PHP example to create a detached signature file (.p7s) for any type file. The signature can be verified by calling VerifyP7S and passing the original filename and the .p7s filename.

Download Chilkat Crypt ActiveX

<?php

$crypt = new COM("Chilkat.Crypt2");

//  Any string argument automatically begins the 30-day trial.
$success = $crypt->UnlockComponent('30-day trial');
if ($success != true) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

//  Use a digital certificate and private key from a PFX file (.pfx or .p12).
$signingCertSubject = 'Acme Inc';
$pfxFilename = '/Users/chilkat/testData/pfx/acme.pfx';
$pfxPassword = 'test123';

$certStore = new COM("Chilkat.CertStore");
$success = $certStore->LoadPfxFile($pfxFilename,$pfxPassword);
if ($success != true) {
    print $certStore->lastErrorText() . "\n";
    exit;
}

// cert is a Chilkat.Cert
$cert = $certStore->FindCertBySubjectCN($signingCertSubject);
if (is_null($cert)) {
    print 'Failed to find certificate by subject common name.' . "\n";
    exit;
}

//  Tell the crypt component to use this cert.
$crypt->SetSigningCert($cert);

//  We can sign any type of file, creating a .p7s as output:
$inFile = '/Users/chilkat/testData/pdf/sample.pdf';
$sigFile = '/Users/chilkat/testData/p7s/sample.p7s';

$success = $crypt->CreateP7S($inFile,$sigFile);
if ($success == false) {
    print $crypt->lastErrorText() . "\n";

    exit;
}

$success = $crypt->VerifyP7S($inFile,$sigFile);
if ($success == false) {
    print $crypt->lastErrorText() . "\n";

    exit;
}

print 'Success!' . "\n";
?>