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PHP

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

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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 PHP
<?php

use Chilkat2\Mime;

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

$mime = new Mime();
try {
    $mime->LoadMimeFile('qa_data/signed.eml');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

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