/**
* Generate a signature based on client properties/options and the transaction specific data
*
* @param string $params The required variables to create the signature as an http query
*
* @return string
*/
public function generateSignature($params = '')
{
$params = urldecode($params);
return hash_hmac($this->client->options['algorithm'], $params, $this->client->getSecret(true));
}
