SimpleSAML_XML_Shib13_AuthnResponse::getIssuer PHP Method

    public function getIssuer()
    {
        $query = '/shibp:Response/shib:Assertion/@Issuer';
        $nodelist = $this->doXPathQuery($query);
        if ($attr = $nodelist->item(0)) {
            return $attr->value;
        } else {
            throw new Exception('Could not find Issuer field in Authentication response');
        }
    }

$spMetadata = $source->getMetadata();
if (array_key_exists('SAMLart', $_REQUEST)) {
    if (!isset($state['saml:idp'])) {
        /* Unsolicited response. */
        throw new SimpleSAML_Error_Exception('IdP initiated authentication not supported with the SAML 1.1 SAMLart protocol.');
    }
    $idpMetadata = $source->getIdPMetadata($state['saml:idp']);
    $responseXML = SimpleSAML_Bindings_Shib13_Artifact::receive($spMetadata, $idpMetadata);
    $isValidated = TRUE;
    /* Artifact binding validated with ssl certificate. */
} elseif (array_key_exists('SAMLResponse', $_REQUEST)) {
    $responseXML = $_REQUEST['SAMLResponse'];
    $responseXML = base64_decode($responseXML);
    $isValidated = FALSE;
    /* Must check signature on response. */
} else {
    assert('FALSE');
}
$response = new SimpleSAML_XML_Shib13_AuthnResponse();
$response->setXML($responseXML);
$response->setMessageValidated($isValidated);
$response->validate();
$responseIssuer = $response->getIssuer();
$attributes = $response->getAttributes();
if (isset($state['saml:idp']) && $responseIssuer !== $state['saml:idp']) {
    throw new SimpleSAML_Error_Exception('The issuer of the response wasn\'t the destination of the request.');
}
$logoutState = array('saml:logout:Type' => 'saml1');
$state['LogoutState'] = $logoutState;
$source->handleResponse($state, $responseIssuer, $attributes);
assert('FALSE');