Method isChecksumValid

/**
 * Return the result of the checksum of a package with the SHA256/SHA384/SHA512 tags in the update server manifest
 *
 * @param   string  $packagefile   Location of the package to be installed
 * @param   Update  $updateObject  The Update Object
 *
 * @return  integer  one if the hashes match, zero if hashes doesn't match, two if hashes not found
 *
 * @since   3.9.0
 */
public static function isChecksumValid($packagefile, $updateObject)
{
    $hashes = array('sha256', 'sha384', 'sha512');
    $hashOnFile = false;
    foreach ($hashes as $hash) {
        if ($updateObject->get($hash, false)) {
            $hashPackage = hash_file($hash, $packagefile);
            $hashRemote = $updateObject->{$hash}->_data;
            $hashOnFile = true;
            if ($hashPackage !== strtolower($hashRemote)) {
                return self::HASH_NOT_VALIDATED;
            }
        }
    }
    if ($hashOnFile) {
        return self::HASH_VALIDATED;
    }
    return self::HASH_NOT_PROVIDED;
}