/**
* Método que firma un XML utilizando RSA y SHA1
*
* Referencia: http://www.di-mgt.com.au/xmldsig2.html
*
* @param xml_data Archivo XML que se desea firmar, debe venir con elemento Signature
* @return XML firmado
* @author Esteban De La Fuente Rubio, DeLaF (esteban[at]sasco.cl)
* @version 2014-12-08
*/
public function signXML($xml_data)
{
$doc = new \DomDocument();
$doc->loadXML($xml_data);
$dom = $doc->documentElement;
// calcular DigestValue y SignatureValue
$Signature = $dom->removeChild($dom->getElementsByTagName('Signature')[0]);
$digest = base64_encode(sha1($dom->C14N(), true));
$Signature->getElementsByTagName('DigestValue')[0]->nodeValue = $digest;
$SignedInfo = $Signature->getElementsByTagName('SignedInfo')[0];
$SignedInfo->setAttribute('xmlns', $Signature->getAttribute('xmlns'));
$SignedInfo = $doc->saveHTML($SignedInfo);
$signature = wordwrap($this->sign($SignedInfo), $this->config['wordwrap'], "\n", true);
// reemplazar valores en la firma de
$Signature->getElementsByTagName('SignatureValue')[0]->nodeValue = $signature;
$Signature->getElementsByTagName('Modulus')[0]->nodeValue = $this->getModulus();
$Signature->getElementsByTagName('Exponent')[0]->nodeValue = $this->getExponent();
$Signature->getElementsByTagName('X509Certificate')[0]->nodeValue = $this->cleanCert($this->certs['cert']);
// agregar y entregar firma
$dom->appendChild($Signature);
return $doc->C14N();
}
