/**
* Generate a config string from an array.
*
* @param array $config Array of configuration options.
* @return string Configuration string.
* @throws InvalidArgumentException Throws an InvalidArgumentException if
* any passed-in configuration options are invalid.
*/
public static function genConfig(array $config = array())
{
$defaults = array('rounds' => 5001, 'salt' => Utilities::encode64(Utilities::genRandomBytes(3)));
$config = array_merge($defaults, array_change_key_case($config, CASE_LOWER));
$string = '*1';
if (self::validateOptions($config)) {
// Rounds needs to be odd in order to avoid exposing weak DES keys
if ($config['rounds'] % 2 == 0) {
--$config['rounds'];
}
$string = sprintf('_%s%s', Utilities::encodeInt24($config['rounds']), $config['salt']);
}
return $string;
}
