private static function httpDigestParse($txt)
	{
		// protect against missing data
		$needed_parts = array('nonce'=>1, 'nc'=>1, 'cnonce'=>1, 'qop'=>1, 'username'=>1, 'uri'=>1, 'response'=>1);
		$data = array();
		$keys = implode('|', array_keys($needed_parts));

		preg_match_all('@(' . $keys . ')=(?:([\'"])([^\2]+?)\2|([^\s,]+))@', $txt, $matches, PREG_SET_ORDER);

		foreach ($matches as $m) {
			$data[$m[1]] = $m[3] ? $m[3] : $m[4];
			unset($needed_parts[$m[1]]);
		}

		return $needed_parts ? false : $data;
	}