SAML2\Assertion::toXML PHP Method

    public function toXML(\DOMNode $parentElement = null)
    {
        if ($parentElement === null) {
            $document = DOMDocumentFactory::create();
            $parentElement = $document;
        } else {
            $document = $parentElement->ownerDocument;
        }
        $root = $document->createElementNS(Constants::NS_SAML, 'saml:' . 'Assertion');
        $parentElement->appendChild($root);
        /* Ugly hack to add another namespace declaration to the root element. */
        $root->setAttributeNS(Constants::NS_SAMLP, 'samlp:tmp', 'tmp');
        $root->removeAttributeNS(Constants::NS_SAMLP, 'tmp');
        $root->setAttributeNS(Constants::NS_XSI, 'xsi:tmp', 'tmp');
        $root->removeAttributeNS(Constants::NS_XSI, 'tmp');
        $root->setAttributeNS(Constants::NS_XS, 'xs:tmp', 'tmp');
        $root->removeAttributeNS(Constants::NS_XS, 'tmp');
        $root->setAttribute('ID', $this->id);
        $root->setAttribute('Version', '2.0');
        $root->setAttribute('IssueInstant', gmdate('Y-m-d\\TH:i:s\\Z', $this->issueInstant));
        if (is_string($this->issuer)) {
            $issuer = Utils::addString($root, Constants::NS_SAML, 'saml:Issuer', $this->issuer);
        } elseif ($this->issuer instanceof \SAML2\XML\saml\Issuer) {
            $issuer = $this->issuer->toXML($root);
        }
        $this->addSubject($root);
        $this->addConditions($root);
        $this->addAuthnStatement($root);
        if ($this->requiredEncAttributes == false) {
            $this->addAttributeStatement($root);
        } else {
            $this->addEncryptedAttributeStatement($root);
        }
        if ($this->signatureKey !== null) {
            Utils::insertSignature($this->signatureKey, $this->certificates, $root, $issuer->nextSibling);
        }
        return $root;
    }

 /**
  * Set the assertion.
  *
  * @param \SAML2\Assertion $assertion The assertion.
  * @param XMLSecurityKey  $key       The key we should use to encrypt the assertion.
  * @throws \Exception
  */
 public function setAssertion(Assertion $assertion, XMLSecurityKey $key)
 {
     $xml = $assertion->toXML();
     Utils::getContainer()->debugMessage($xml, 'encrypt');
     $enc = new XMLSecEnc();
     $enc->setNode($xml);
     $enc->type = XMLSecEnc::Element;
     switch ($key->type) {
         case XMLSecurityKey::TRIPLEDES_CBC:
         case XMLSecurityKey::AES128_CBC:
         case XMLSecurityKey::AES192_CBC:
         case XMLSecurityKey::AES256_CBC:
             $symmetricKey = $key;
             break;
         case XMLSecurityKey::RSA_1_5:
         case XMLSecurityKey::RSA_OAEP_MGF1P:
             $symmetricKey = new XMLSecurityKey(XMLSecurityKey::AES128_CBC);
             $symmetricKey->generateSessionKey();
             $enc->encryptKey($key, $symmetricKey);
             break;
         default:
             throw new \Exception('Unknown key type for encryption: ' . $key->type);
     }
     $this->encryptedData = $enc->encryptNode($symmetricKey);
 }