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.

 Chilkat Perl Module Downloads for Windows, Linux, and MAC OS X

use chilkat();

$cert = new chilkat::CkCert();

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

$pkey = new chilkat::CkPrivateKey();

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

$success = $cert->SetPrivateKey($pkey);
if ($success != 1) {
    print $cert->lastErrorText() . "\r\n";
    exit;
}

#  Use Chilkat Crypt (a non-freeware component) to create
#  a digital signature using the certificate w/ private key:
$crypt = new chilkat::CkCrypt2();

#  Any string argument automatically begins the 30-day trial.
$success = $crypt->UnlockComponent("30-day trial");
if ($success != 1) {
    print $crypt->lastErrorText() . "\r\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 == 0) {
    print $crypt->lastErrorText() . "\r\n";
    exit;
}

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

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

$success = $crypt->VerifyP7S("license.rtf","license.p7s");
if ($success == 0) {
    print $crypt->lastErrorText() . "\r\n";
    exit;
}

print "Success!" . "\n";