php圖片驗證碼代碼

2024-09-04 11:44:21

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在用戶驗證頁面,如注冊,登錄的時候,為了加強用戶登錄的安全性,添加驗證碼驗證代碼,下面我為各位朋友提供幾種不同同類型的php驗證代碼程序,最后一款是一款使用了驗證代碼的實例代碼,實例代碼如下:

date_default_timezone_set('asia/shanghai');

function setcode($len)

{

  $code = '';

  for ($i=0;$i<$len;$i++)//生成隨機長度

  {

   $code .= chr(drand());

  }

  return $code;

}

//生成一個隨機字符

function drand()

{

  $rand = mt_rand(0,2);

  $str = '';

  switch ($rand)

  {

   case 0: $str = mt_rand(48,57);break;//數字

   case 1: $str = mt_rand(65,90);break;//大寫字母

   case 2: $str = mt_rand(97,122);break;//小寫字母

  }

  return $str;

}

$_session['checkcode'] = $code = setcode(5);

//php圖片驗證碼原代碼，需支持gd2.dll擴展，需修改php.ini后重啟iis or ap

session_start();

session_register('safecode');

$type = 'gif';

$width= 40;

$height= 16;

header("content-type: image/".$type);

srand((double)microtime()*1000000);

$randval = randstr(4,"");

if($type!='gif' && function_exists('imagecreatetruecolor')){

     $im = @imagecreatetruecolor($width,$height);

}else{

     $im = @imagecreate($width,$height);

}

     $r = array(225,211,255,223);

     $g = array(225,236,237,215);

     $b = array(225,236,166,125);

     $key = rand(0,3);



     $backcolor = imagecolorallocate($im,$r[$key],$g[$key],$b[$key]);//背景色（隨機）

     $bordercolor = imagecolorallocate($im, 0, 0, 0);//邊框色

     $pointcolor = imagecolorallocate($im, 255, 170, 255);//點顏色

     @imagefilledrectangle($im, 0, 0, $width - 1, $height - 1, $backcolor);//背景位置

     @imagerectangle($im, 0, 0, $width-1, $height-1, $bordercolor); //邊框位置

     $stringcolor = imagecolorallocate($im, 255,51,153);

     for($i=0;$i<=100;$i++){

           $pointx = rand(2,$width-2);

           $pointy = rand(2,$height-2);

           @imagesetpixel($im, $pointx, $pointy, $pointcolor);

     }

     @imagestring($im, 3, 5, 1, $randval, $stringcolor);

     $imagefun='image'.$type;

     $imagefun($im);

     @imagedestroy($im);

     $_session['safecode'] = $randval;

//產生隨機字符串

function randstr($len=6,$format='all') {

           switch($format) {

                 case 'all':

                 $chars='abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789www.111cn.net'; break;

                 case 'char':

                 $chars='abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz'; break;

                 case 'number':

                 $chars='0123456789'; break;

                 default :

                 $chars='abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789';

                 break;

           }

     $string="";

     while(strlen($string)<$len)

     $string.=substr($chars,(mt_rand()%strlen($chars)),1);

     return $string;

}

//調用此頁面，如果下面的式子成立，則生成驗證碼圖片

if($_get["action"]=="verifycode")

{

    rand_create();

}

//驗證碼圖片生成

function rand_create()

{

    //通知瀏覽器將要輸出png圖片

    header("content-type: image/png");

    //準備好隨機數發生器種子

    srand((double)microtime()*1000000);

    //準備圖片的相關參數

    $im = imagecreate(62,20);

    $black = imagecolorallocate($im, 0,0,0);  //rgb黑色標識符

    $white = imagecolorallocate($im, 255,255,255); //rgb白色標識符

    $gray = imagecolorallocate($im, 200,200,200); //rgb灰色標識符

    //開始作圖

    imagefill($im,0,0,$gray);

    while(($randval=rand()%100000)<10000);{

        $_session["login_check_num"] = $randval;

        //將四位整數驗證碼繪入圖片

        imagestring($im, 5, 10, 3, $randval, $black);

    }

    //加入干擾象素

    for($i=0;$i<200;$i++){

        $randcolor = imagecolorallocate($im,rand(0,255),rand(0,255),rand(0,255));

        imagesetpixel($im, rand()%70 , rand()%30 , $randcolor);

    }

    //輸出驗證圖片

    imagepng($im);

    //銷毀圖像標識符

    imagedestroy($im);

}

//檢驗驗證碼

function rand_check()

{

    if($_post["reg_rand"] == $_session["login_check_num"]){

        return true;

    } //開源代碼Vevb.com

    else{

        exit("驗證碼輸入錯誤");

    }

}