private function convertPrivateKeyToRsaKey(PrivateKey $privateKey) { $key = new XMLSecurityKey(XMLSecurityKey::RSA_1_5, array('type' => 'private')); $passphrase = $privateKey->getPassphrase(); if ($passphrase) { $key->passphrase = $passphrase; } $key->loadKey($privateKey->getKeyAsString()); return $key; }