private function calculateSignatureAndParametersToString($parameters = array()) { $parameters['AWSAccessKeyId'] = $this->config->getAccessKey(); $parameters['Version'] = self::SERVICE_VERSION; $parameters['SignatureMethod'] = 'HmacSHA256'; $parameters['SignatureVersion'] = 2; $parameters['Timestamp'] = $this->getFormattedTimestamp(); uksort($parameters, 'strcmp'); $this->createServiceUrl(); $parameters['Signature'] = $this->signParameters($parameters); $parameters = $this->getParametersAsString($parameters); // Save these parameters in the parameters variable so that it can be returned for unit testing. $this->parameters = $parameters; return $parameters; }