src/Omnipay/Ecopayz/Message/CompletePurchaseRequest.php
public function validateChecksum($string)
    {
        $xml = new \SimpleXMLElement($string);
        $checksum = (string) $xml->Authentication->Checksum;
        $original = str_replace($checksum, $this->getMerchantPassword(), $string);

        return md5($original) == $checksum;
    }
public function validateChecksum($string)
    {
        $xml = new \SimpleXMLElement($string);
        $checksum = (string) $xml->Authentication->Checksum;
        $original = str_replace($checksum, $this->getMerchantPassword(), $string);

        return md5($original) == $checksum;
    }
Validate Ecopayz XML message

@param  string $string The xml string to validate
@return bool   result