PHP保证cookie安全

[php]代码库

/**<br> * 生成随机数<br> * <br> * @param int $length  生成的随机数的长度<br> * @param int $numeric 是否生成数字随机数的标志<br> */<br>function random($length, $numeric = 0) {<br>    PHP_VERSION < '4.2.0' && mt_srand((double)microtime() * 1000000);<br>    if ($numeric) {<br>        $begin = pow(10, $length - 1);<br>        $end   = pow(10, $length) - 1;<br>        $hash = sprintf('%0'.$length.'d', mt_rand($begin, $end));<br>    } else {<br>        $hash = '';<br>        $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz';<br>        $max = strlen($chars) - 1;<br>        for($i = 0; $i < $length; $i++) {<br>            $hash .= $chars[mt_rand(0, $max)];<br>        }<br>    }<br>    return $hash;<br>}