public function canValidate(SignedElement $signedElement, CertificateProvider $configuration)
{
if ($configuration->getCertificateFingerprints() === null) {
$this->logger->debug('Configuration does not have "certFingerprint" value, cannot validate signature with fingerprint');
return false;
}
// use internal cache to prevent doing certificate extraction twice.
$this->certificates = $signedElement->getCertificates();
if (empty($this->certificates)) {
$this->logger->debug('Signed element does not have certificates, cannot validate signature with fingerprint');
return false;
}
return true;
}
/**
* Check the signature on a SAML2 message or assertion.
*
* @param SimpleSAML_Configuration $srcMetadata The metadata of the sender.
* @param \SAML2\SignedElement $element Either a \SAML2\Response or a \SAML2\Assertion.
*/
public static function checkSign(SimpleSAML_Configuration $srcMetadata, \SAML2\SignedElement $element)
{
/* Find the public key that should verify signatures by this entity. */
$keys = $srcMetadata->getPublicKeys('signing');
if ($keys !== NULL) {
$pemKeys = array();
foreach ($keys as $key) {
switch ($key['type']) {
case 'X509Certificate':
$pemKeys[] = "-----BEGIN CERTIFICATE-----\n" . chunk_split($key['X509Certificate'], 64) . "-----END CERTIFICATE-----\n";
break;
default:
SimpleSAML\Logger::debug('Skipping unknown key type: ' . $key['type']);
}
}
} elseif ($srcMetadata->hasValue('certFingerprint')) {
SimpleSAML\Logger::notice("Validating certificates by fingerprint is deprecated. Please use " . "certData or certificate options in your remote metadata configuration.");
$certFingerprint = $srcMetadata->getArrayizeString('certFingerprint');
foreach ($certFingerprint as &$fp) {
$fp = strtolower(str_replace(':', '', $fp));
}
$certificates = $element->getCertificates();
/*
* We don't have the full certificate stored. Try to find it
* in the message or the assertion instead.
*/
if (count($certificates) === 0) {
/* We need the full certificate in order to match it against the fingerprint. */
SimpleSAML\Logger::debug('No certificate in message when validating against fingerprint.');
return FALSE;
} else {
SimpleSAML\Logger::debug('Found ' . count($certificates) . ' certificates in ' . get_class($element));
}
$pemCert = self::findCertificate($certFingerprint, $certificates);
$pemKeys = array($pemCert);
} else {
throw new SimpleSAML_Error_Exception('Missing certificate in metadata for ' . var_export($srcMetadata->getString('entityid'), TRUE));
}
SimpleSAML\Logger::debug('Has ' . count($pemKeys) . ' candidate keys for validation.');
$lastException = NULL;
foreach ($pemKeys as $i => $pem) {
$key = new XMLSecurityKey(XMLSecurityKey::RSA_SHA1, array('type' => 'public'));
$key->loadKey($pem);
try {
/*
* Make sure that we have a valid signature on either the response
* or the assertion.
*/
$res = $element->validate($key);
if ($res) {
SimpleSAML\Logger::debug('Validation with key #' . $i . ' succeeded.');
return TRUE;
}
SimpleSAML\Logger::debug('Validation with key #' . $i . ' failed without exception.');
} catch (Exception $e) {
SimpleSAML\Logger::debug('Validation with key #' . $i . ' failed with exception: ' . $e->getMessage());
$lastException = $e;
}
}
/* We were unable to validate the signature with any of our keys. */
if ($lastException !== NULL) {
throw $lastException;
} else {
return FALSE;
}
}