Подпишите файл XML с помощью сертификата .pfx, используя переполнение стека

Вот минимальный пример для подписи xml-файла pfx-файлом:

// Read the pfx file
$cert_store = file_get_contents('localhost.pfx');
$status = openssl_pkcs12_read($cert_store, $cert_info, '12345678');

if (!$status) {
throw new RuntimeException(__('Invalid pasword'));
}

$public_key = $cert_info['cert'];
$private_key = $cert_info['pkey'];

// Read the private key
$pkeyid = openssl_get_privatekey($private_key);

if (!$pkeyid) {
throw new RuntimeException(__('Invalid private key'));
}

// Sign an XML file and save the signature in a new file
// This method does not save the public key within the XML file.
// This file cannot be verified unless
// the verifying code has the key with which it was signed.

// Read the xml file content
$filename = 'example.xml';

$data = file_get_contents($filename);

// Compute signature with SHA-512
$status = openssl_sign($data, $signature, $pkeyid, OPENSSL_ALGO_SHA512);

// Free the key from memory
openssl_free_key($pkeyid);

if (!$status) {
throw new RuntimeException(__('Computing of the signature failed'));
}

//
// Create a SignedXml object.
//
$xml = new DOMDocument();
$xml->load($filename);
$xml->preserveWhiteSpace = true;
$xml->formatOutput = true;

// Encode signature
$signature_value = base64_encode($signature);

// Calulate and encode digest value
$digest_value = base64_encode(hash('sha512', $data, true));

// Get the XML representation of the signature and save
// it to an XmlElement object.
$signatureElement = $xml->createElement('Signature');
$signatureElement->setAttribute('xmlns', 'http://www.w3.org/2000/09/xmldsig#');

$signedInfoElement = $xml->createElement('SignedInfo');
$signatureElement->appendChild($signedInfoElement);

$canonicalizationMethodElement = $xml->createElement('CanonicalizationMethod');
$canonicalizationMethodElement->setAttribute('Algorithm', 'http://www.w3.org/TR/2001/REC-xml-c14n-20010315');
$signedInfoElement->appendChild($canonicalizationMethodElement);

$signatureMethodElement = $xml->createElement('SignatureMethod');
$signatureMethodElement->setAttribute('Algorithm', 'http://www.w3.org/2000/09/xmldsig#rsa-sha512');
$signedInfoElement->appendChild($signatureMethodElement);

$referenceElement = $xml->createElement('Reference');
$referenceElement->setAttribute('URI', '');
$signedInfoElement->appendChild($referenceElement);

$transformsElement = $xml->createElement('Transforms');
$referenceElement->appendChild($transformsElement);

$transformElement = $xml->createElement('Transform');
$transformElement->setAttribute('Algorithm', 'http://www.w3.org/2000/09/xmldsig#enveloped-signature');
$transformsElement->appendChild($transformElement);

$digestMethodElement = $xml->createElement('DigestMethod');
$digestMethodElement->setAttribute('Algorithm', 'http://www.w3.org/2000/09/xmldsig#sha512');
$referenceElement->appendChild($digestMethodElement);

$digestValueElement = $xml->createElement('DigestValue', $digest_value);
$referenceElement->appendChild($digestValueElement);

$signatureValueElement = $xml->createElement('SignatureValue', $signature_value);
$signatureElement->appendChild($signatureValueElement);

// Append the element to the XML document.
// We insert the new element as root (child of the document)
$xml->documentElement->appendChild($signatureElement);

// Save the signed xml file
file_put_contents('signedExample.xml', $xml->saveXML());

Редактировать: проверить это библиотеки

• https://github.com/odan/xmldsig
• https://github.com/giansalex/xmldsig
• https://github.com/Maks3w/xmldsig