Use Certificate and Private Key PEM Files to Create a Digital Signature

Demonstrates how to load a digital certificate from a PEM file, load it's corresponding private key from a PEM file, save the private key to a key container (if necessary), link the certificate to the key container, and use it to create a digital signature.

Download Chilkat Crypt ActiveX

<?php

$cert = new COM("Chilkat.Cert");

//  Load the cert from a PEM file;
$cert->LoadFromFile('cert.pem');

$pkey = new COM("Chilkat.PrivateKey");

//  Load the private key from an RSA PEM file:
$pkey->LoadPemFile('pkey_rsa.pem');

$success = $cert->SetPrivateKey($pkey);
if ($success != true) {
    print $cert->lastErrorText() . "\n";
    exit;
}

//  Use Chilkat Crypt (a non-freeware component) to create
//  a digital signature using the certificate w/ private key:
$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;
}

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

//  A PKCS7 signature for any type of file content can be created:
$success = $crypt->CreateP7S('license.rtf','license.p7s');
if ($success == false) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

print $crypt->lastErrorText() . "\n";

//  Verify and restore the original file:
$crypt->SetVerifyCert($cert);

$success = $crypt->VerifyP7S('license.rtf','license.p7s');
if ($success == false) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

print 'Success!' . "\n";


?>