/** * Sign a request * * @param array $params * @param null|string $method * @param null|string $url * @return string */ public function sign(array $params, $method = null, $url = null) { $rsa = new Zend_Crypt_Rsa(); $rsa->setHashAlgorithm($this->_hashAlgorithm); $sign = $rsa->sign($this->_getBaseSignatureString($params, $method, $url), $this->_key, Zend_Crypt_Rsa::BASE64); return $sign; }