function getSignature(array $params, $method = null)
    {
        ksort($params);
        unset($params['sign']);
        unset($params['signature']);
        array_push($params, $this->secretKey);

        if ($method) {
            array_unshift($params, $method);
        }

        return hash('sha256', join('{up}', $params));
    }
function getSignature(array $params, $method = null)
    {
        ksort($params);
        unset($params['sign']);
        unset($params['signature']);
        array_push($params, $this->secretKey);

        if ($method) {
            array_unshift($params, $method);
        }

        return hash('sha256', join('{up}', $params));
    }
function getSignature ( array $ params , $ method = null ) { ksort ( $ params ) ; unset ( $ params [ 'sign' ] ) ; unset ( $ params [ 'signature' ] ) ; array_push ( $ params , $ this -> secretKey ) ; if ( $ method ) { array_unshift ( $ params , $ method ) ; } return hash ( 'sha256' , join ( '{up}' , $ params ) ) ; }
Create SHA-256 digital signature

@param array $params
@param $method

@return string
Create SHA - 256 digital signature