src/Payum/Be2Bill/Api.php
public function calculateHash(array $params)
    {
        #Alpha sort
        ksort($params);

        $clearString = $this->options['password'];
        foreach ($params as $key => $value) {
            $clearString .= $key.'='.$value.$this->options['password'];
        }

        return hash('sha256', $clearString);
    }
public function calculateHash(array $params)
    {
        #Alpha sort
        ksort($params);

        $clearString = $this->options['password'];
        foreach ($params as $key => $value) {
            $clearString .= $key.'='.$value.$this->options['password'];
        }

        return hash('sha256', $clearString);
    }
@param array $params

@return string