Perl Requires Chilkat v9.5.0.83+

Create CMS Signed File (PDF) with Multiple Signing Certificates

See more Digital Signatures Examples

Demonstrates how to sign a file by adding multiple signatures (multiple certificates). This example signs a PDF file to produce an output file that is a CMS signature wrapping the original PDF. (Note: This is different than modifying a PDF by injecting a signature into the PDF file format.) Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

my $crypt = Chilkat2::Crypt2->new;

my $cert1 = Chilkat2::Cert->new;
my $success = $cert1->LoadPfxFile('qa_data/pfx/cert_test123.pfx', 'test123');
if (!$success) {
    print $cert1->LastErrorText, "\n";
    exit;
}

my $cert2 = Chilkat2::Cert->new;
$success = $cert2->LoadPfxFile('qa_data/pfx/test_secret.pfx', 'secret');
if (!$success) {
    print $cert2->LastErrorText, "\n";
    exit;
}

# Tell the crypt component to use both certificates for signing.
# When we create the signature, it will be signed by both certificates.
$success = $crypt->AddSigningCert($cert1);
if (!$success) {
    print $crypt->LastErrorText, "\n";
    exit;
}

$success = $crypt->AddSigningCert($cert2);
if (!$success) {
    print $crypt->LastErrorText, "\n";
    exit;
}

# The CadesEnabled property applies to all methods that create PKCS7 signatures.
# To create a CAdES-BES signature, set this property equal to true.
$crypt->CadesEnabled(1);

$crypt->HashAlgorithm('sha256');

# We can sign any type of file, creating a .p7s as output.
# The .p7s contains the signature and also embeds the data of the file that is signed.
my $inFile = 'qa_data/pdf/sample.pdf';
my $p7sFile = 'qa_output/sample.pdf.p7s';

# Create the CAdES-BES attached signature, which contains the original data.
# Note: Chilkat's function naming is not accurate.  CreateP7M creates a PKCS7 signature where the signed file
# is contained within the signature.  CreateP7S creates a detached PKCS7 signature where the signed file
# is NOT contained within the signature.  We want the data to be contained in the signature, therefore
# we call CreateP7M even though we are naming our output file .p7s.
$success = $crypt->CreateP7M($inFile, $p7sFile);
if (!$success) {
    print $crypt->LastErrorText, "\n";
    exit;
}

# Verify the .p7s file and extract the original file from the .p7s.
my $extractedToFilePath = 'qa_output/sample.pdf';
$success = $crypt->VerifyP7M($p7sFile, $extractedToFilePath);
if (!$success) {
    print $crypt->LastErrorText, "\n";
    exit;
}

print "Success!\n";