Perl

Check if a MIME Entity is Signed (S/MIME)

Demonstrates the Chilkat Mime.IsSigned method, which returns whether the entity is a complete CMS/PKCS #7 signed S/MIME wrapper, including detached multipart/signed and opaque forms. It takes no arguments.

Note: The file path is relative to the application's current working directory. Absolute paths may also be used. Supply the path to your own file.

Background: Before verifying a signature you need to know one is present, and this is the check. A signed S/MIME message comes in two shapes — detached (multipart/signed, signature alongside the content) and opaque (application/pkcs7-mime, content wrapped inside the signature) — and this recognizes both. Follow a true result with Verify.

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Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

# Demonstrates the Mime.IsSigned method, which returns whether the entity is a complete CMS/PKCS #7 signed S/MIME wrapper.  It takes no arguments.

my $mime = Chilkat2::Mime->new;
my $success = $mime->LoadMimeFile('qa_data/signed.eml');
if (!$success) {
    print $mime->LastErrorText, "\n";
    exit;
}

if ($mime->IsSigned()) {
    print "This is a signed S/MIME message.\n";
} else {
    print "This is not a signed S/MIME message.\n";
}