Perl Requires Chilkat v9.5.0.90+

CMS Sign Hash

Demonstrates how to use the SignHashENC method to sign a pre-computed hash. This method creates a CMS signature (PKCS7 detached signature). Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

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

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

# Create the hash to be signed...
$crypt->HashAlgorithm('sha256');
$crypt->EncodingMode('base64');
$crypt->Charset('utf-8');
# Create the SHA256 hash of a string using the utf-8 byte representation.
# Return the hash as base64.
my $base64Hash = $crypt->HashStringENC('This is the string to be hashed');

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

$crypt->SetSigningCert($cert);

# Sign the hash to create a base64 CMS signature (which does not contain the original data).
# We can get the signature in a single line of base64 by specifying "base64", or
# we can get multi-line base64 by specifying "base64_mime".
$crypt->EncodingMode('base64_mime');
my $base64CmsSig = $crypt->SignHashENC($base64Hash, 'sha256', 'base64');
if (!$crypt->LastMethodSuccess) {
    print $crypt->LastErrorText, "\n";
    exit;
}

# Note: In the above call to SignHashENC, the encoding of the returned CMS signature is specified by the EncodingMode property.
# However, the encoding of the passed-in hash is indicated by the 3rd argument.

print 'CMS Signature: ', $base64CmsSig, "\n";