php验证码实现局部刷新

function Auth_code($width = 80,$height = 20,$num = 4,$line = 4,$dot = 150) {

 $length = floor($width/$num);  //floor:取整数部分 length:每段平均长度
 for($i=0;$i<$num;$i++)
  @$rand.=dechex(mt_rand(1,15));
 $_SESSION['code']=$rand;
 
 //新建一个黑色底的画板
 $im=imagecreatetruecolor($width,$height);
 
 //取色
 $green=imagecolorallocate($im,0,255,0);
 $red = imagecolorallocate($im,255,0,0);
 $white=imagecolorallocate($im,255,255,255);
 $black = imagecolorallocate($im,0,0,0);
 
 //填充画板
 //imagefill($im,0,0,$green);
   
 //画线
 for($i=0;$i<$line;$i++){
  $color=imagecolorallocate($im,rand(0,255),rand(0,255),rand(0,255));
  imageline($im,rand(10,$width-10),0,rand(0,$width),$height,$color);
 }
 //画点
 for($i=0;$i<$dot;$i++){
  $color=imagecolorallocate($im,rand(0,255),rand(0,255),rand(0,255));
  imagesetpixel($im,rand(0,$width),rand(0,$height),$color);
 }
 //画数字
 for($i=0;$i<$num;$i++) { 
  imagestring($im,5,mt_rand($i*$length+1,($i+1)*$length-8),mt_rand(0,$height-14),$_SESSION['code'][$i],$white);
 }
 
 //输出图片
 header("content-type:image/jpeg");
 imagejpeg($im);
}

<?php
public function captcha(){
$font_dir = $_SERVER ["DOCUMENT_ROOT"] . "your_ttf_file.ttf"; // 字体库
$img_w = 58; // 设置图片宽
$img_h = 20; // 设置图片高
$font_size = 11; // 字体大小
$angle_l = -10; // 左偏角
$angle_r = 10; // 右偏角
$code_str = "ABCDEFGHJKLMNPQRSTUVWXYZ36";
$word_len = 4; // 验证码位数
$padding = 5; // 每两个文字之间间隔
$margin = 2; // 左侧边距
$base_line = 15; // 文字基线位置
$base_line_offset = 2; // 基准线偏移量
$pixel_num = 3; // 杂点数目基数
$pixel_color= 8; // 杂点只有 $pixel_color 种颜色 总的杂点数为$pixel_num*$pixel_color
$noise_font_size = 1; // 杂点字体大小
$session_key= "my.xoyo_captcha"; //自定义session键名

header("Cache-Control: no-cache, must-revalidate");
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Pragma: no-cache");
header("Cache-control: private");
header('Content-Type: image/png');

session_start();
$word = "";
$code_str_len = strlen($code_str) - 1;
for ($i = 0; $i < $word_len; $i++) {
$word.= $code_str[rand(0, $code_str_len)];
}
$_SESSION [$session_key] = strtolower($word);
$image = imagecreatetruecolor($img_w, $img_h);
imagefilledrectangle($image, 0, 0, $img_w - 1, $img_h - 1, imagecolorallocate($image, mt_rand(235, 255), mt_rand(235, 255), mt_rand(235, 255)));

//绘制杂点
for($i = 0; $i < $pixel_color; $i++){
$noise_color = imagecolorallocate( $image, mt_rand(150,225), mt_rand(150,225), mt_rand(150,225) );
for($j = 0; $j < $pixel_num; $j++) {
imagestring( $image, $noise_font_size, mt_rand(-10, $img_w), mt_rand(-10, $img_h), $code_str[mt_rand(0, $code_str_len)], $noise_color );
}
}

//绘制文字
for ($i = 0; $i < $word_len; ++$i) {
$color = imagecolorallocate($image, mt_rand(0, 100), mt_rand(20, 120), mt_rand(50, 150));
imagettftext($image, $font_size, mt_rand($angle_l, $angle_r), $margin, mt_rand($base_line-$base_line_offset, $base_line+$base_line_offset), $color, $font, mb_substr($word, $i, 1, 'utf-8'));
$margin += (imagefontwidth($font_size) + $padding);
}

imagepng($image);
imagedestroy($image);
exit;
}

代码如下:
<?php
   /*   网站验证码程序
    *   运行环境： PHP5.0.18 下调试通过
    *   需要 gd2 图形库支持（PHP.INI中 php_gd2.dll开启）
    *   文件名: showimg.php
    *   作者：  17php.com
    *   Date:   2007.03
    */

   //随机生成一个4位数的数字验证码
    $num="";
    for($i=0;$i<4;$i++){
    $num .= rand(0,9);
    }
   //4位验证码也可以用rand(1000,9999)直接生成
   //将生成的验证码写入session，备验证页面使用
    Session_start();
    $_SESSION["Checknum"] = $num;
   //创建图片，定义颜色值
    Header("Content-type: image/PNG");
    srand((double)microtime()*1000000);
    $im = imagecreate(60,20);
    $black = ImageColorAllocate($im, 0,0,0);
    $gray = ImageColorAllocate($im, 200,200,200);
    imagefill($im,0,0,$gray);

    //随机绘制两条虚线，起干扰作用
    $style = array($black, $black, $black, $black, $black, $gray, $gray, $gray, $gray, $gray);
    imagesetstyle($im, $style);
    $y1=rand(0,20);
    $y2=rand(0,20);
    $y3=rand(0,20);
    $y4=rand(0,20);
    imageline($im, 0, $y1, 60, $y3, IMG_COLOR_STYLED);
    imageline($im, 0, $y2, 60, $y4, IMG_COLOR_STYLED);

    //在画布上随机生成大量黑点，起干扰作用;
    for($i=0;$i<80;$i++)
    {
   imagesetpixel($im, rand(0,60), rand(0,20), $black);
    }
    //将四个数字随机显示在画布上,字符的水平间距和位置都按一定波动范围随机生成
    $strx=rand(3,8);
    for($i=0;$i<4;$i++){
    $strpos=rand(1,6);
    imagestring($im,5,$strx,$strpos, substr($num,$i,1), $black);
    $strx+=rand(8,12);
    }
    ImagePNG($im);
    ImageDestroy($im);
   ?>

http://www.xxx.com/index.php?page=../etc/passwd
http://www.xxx.com/index.php?page=../../../etc/passwd
http://www.xxx.com/index.php?page=..../../etc/passwd

获取更多数据:
etc/profile
etc/services
/etc/passwd
/etc/shadow
/etc/group
/etc/security/group
/etc/security/passwd
/etc/security/user
/etc/security/environ
/etc/security/limits
/usr/lib/security/mkuser.default

?page=intval($_GET);

$body = htmlspecialchars(isset($_GET[$str])?$_GET[$str]:'');

<?php   
/*   
* 文件:chinesechar.php   
* 作用:汉字数据储存   
*/   
$ChineseChar = array("人","出","来","友","学","孝","仁","义","礼","廉","忠","国","中","易","白","者","火 ","土","金","木","雷","风","龙","虎","天","地",   "生","晕","菜","鸟","田","三","百","钱","福 ","爱","情","兽","虫","鱼","九","网","新","度","哎","唉","啊","哦","仪","老","少","日",   "月 ","星");   
?>   

<?php   
/*   
* 文件:check.php   
* 作用:验证   

*/   
session_start();   
$errorMSG = '';   
//验证用户输入是否和验证码一致   
if(!is_null($_POST['check']))   
{   
        if (strcasecmp($_SESSION['code'],$_POST['code'])==0)   
            $errorMSG = "<p style="font-size:12px;color:#009900">验证成功!</p>";   
        else   
            $errorMSG = "<p style="font-size:12px;color:#FF0000">验证失败!</p>";   
}   
?>   
<html>   
<head>   
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">   
</head>   
<body>   
<?php   
if($errorMSG){   
echo $errorMSG;   
}   
?>   
<form action=<?php echo $_SERVER['PHP_SELF']?> method=post>   
请输入验证码：<input type="text" name="code" style="width:   
80px"><img src="code.php">   
<br>   
<input type="submit" name="check" value="提交验证码">   
</form>   
</body>   
</html>   

<?php   
/*   
* 文件:code.php   
* 作用:验证码生成   
 
* 特注:由 没牙的草 指导 版权所有转载注明出处!有付出才会有收获! 
*/   
include_once("chinesechar.php");   
session_start();   
// 设置 content-type   
header("Content-type: image/png");   
// 创建图片   
$im = imagecreatetruecolor(120, 30);   

// 创建颜色   
$fontcolor = imagecolorallocate($im, 255, 255, 255);   
$bg = imagecolorallocate($im, 0, 0, 0);   

// 设置文字   
for($i=0;$i<4;$i++) $text .= $ChineseChar[(array_rand($ChineseChar))];   

$_SESSION['code'] = $text;   
// 设置字体   
$font = 'simkai.ttf';   

// 添加文字   
imagettftext($im, 18, 0, 11, 21, $fontcolor, $font, iconv("GB2312","UTF-8",$text));   

// 输出图片   
imagepng($im);   
imagedestroy($im);   
?>