用php做出類似Google的字詞驗證圖片

雖然日前Google字詞驗證與CAPTCHA都已經宣告被破解, 但還是用php來寫出一個類似的介面, php圖片要扭曲必須要用像素位移的方式, 所以出來的圖片會有一點沙沙的感覺。 其實也可以使用其他附加軟體進行扭曲的動作, 但那樣可攜性就相對降低了。
使用時請在這支php同資料夾加上font資料夾, 裡面放置要產生驗證碼的字型, 幾個都可以, 會隨機挑選, 驗證碼存在$_SESSION['vCode']中, 格式為 驗證碼|時間, 比對時要explode("|", $_SESSION['vCode'])。

也可以加上干擾線條與點數, 變的更難辨識。

測試檔案打包下載

<?php

session_start();   // if header already send, change output_buffering = On at php.ini. otherwise save as UTF-8 without BOM.

$vi = new vCodeImage();
$vi -> SetImage(2,7,130,60,120,1);

class vCodeImage
{
    var $mode;            // 1.文字模式, 2.字母模式, 3.文字字母混合模式, 4.其他文字字母優化模式
    var $v_num;            // 驗證碼個數
    var $img_w;            // 圖像寬度
    var $img_h;            // 圖像�度
    var $int_pixel_num; // 干擾像數個數
    var $int_line_num;    // 干擾線條數量
    var $font_dir;        // 字型文件路徑
    var $border;        // 圖像邊框
    var $borderColor;    // 圖像邊框顏色

    function SetImage($mode, $v_num, $img_w, $img_h, $int_pixel_num, $int_line_num, $font_dir='font', $border=false, $borderColor='0,0,0')
    {
        if(!isset($_SESSION['vCode'])){
            session_register('vCode');
        }
        $_SESSION['vCode'] = "";

        $this -> mode = $mode;
        $this -> v_num = $v_num;
        $this -> img_w = $img_w;
        $this -> img_h = $img_h;
        $this -> int_pixel_num = $int_pixel_num;
        $this -> int_line_num = $int_line_num;
        $this -> font_dir = $font_dir;
        $this -> border = $border;
        $this -> borderColor = $borderColor;
        $this -> GenerateImage();
    }

    function GetChar($mode)
    {
        if($mode == "1"){
            $ychar = "0,1,2,3,4,5,6,7,8,9";
        }else if($mode == "2"){
            $ychar = "a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z";
        }else if($mode == "3"){
            $ychar = "0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z";
        }else{
            $ychar = "3,4,5,6,7,8,9,a,b,c,d,h,k,p,r,s,t,w,x,y";
        }
        return $ychar;
    }
 
    function RandColor($rs, $re, $gs, $ge, $bs, $be)
    {
        $r = mt_rand($rs, $re);
        $g = mt_rand($gs, $ge);
        $b = mt_rand($bs, $be);
        return array($r, $g, $b);
    }
 
    function GenerateImage()
    {
        $fonts = scandir($this -> font_dir);
        $ychar = $this -> GetChar($this -> mode);
        $list = explode(",", $ychar);
        $cmax = count($list) - 1;
        $fmax = count($fonts) - 2;
        $fontrand = mt_rand(2, $fmax);
        $font = $this -> font_dir."/".$fonts[$fontrand];

        // 驗證碼
        $v_code = "";
        for($i = 0; $i < $this-> v_num; $i++){    
            $randnum = mt_rand(0, $cmax);
            $this_char = $list[$randnum];
            $v_code .= $this_char;
        }

        // 扭曲圖形
        $im = imagecreatetruecolor ($this -> img_w + 50, $this -> img_h);
        $color = imagecolorallocate($im, 32, 81, 183);
        $ranum = mt_rand(0, 2);
        if($ranum == 0){
            $color = imagecolorallocate($im, 32, 81, 183);
        }else if($ranum == 1){
            $color = imagecolorallocate($im, 17, 158, 20);
        }else{
            $color = imagecolorallocate($im, 196, 31, 11);
        }
        imagefill($im, 0, 0, imagecolorallocate($im, 255, 255, 255) );
        imagettftext ($im, 24, mt_rand(-6, 6), 10, $this -> img_h * 0.6, $color, $font, $v_code);

        // 干擾線條
        for($i = 0; $i < $this -> int_line_num; $i++){
            $rand_color_line = $color;
            imageline($im, mt_rand(2,intval($this -> img_w/3)), mt_rand(10,$this -> img_h - 10), mt_rand(intval($this -> img_w - ($this -> img_w/3) + 50),$this -> img_w), mt_rand(0,$this -> img_h), $rand_color_line);
        }

        $ranum = mt_rand(0, 1);
        $dis_range = mt_rand(8, 12);
        $distortion_im = imagecreatetruecolor ($this -> img_w * 1.5 ,$this -> img_h);        
        imagefill($distortion_im, 0, 0, imagecolorallocate($distortion_im, 255, 255, 255));
        for ($i = 0; $i < $this -> img_w + 50; $i++) {
            for ($j = 0; $j < $this -> img_h; $j++) {
                $rgb = imagecolorat($im, $i, $j);
                if($ranum == 0){
                    if( (int)($i+40+cos($j/$this -> img_h * 2 * M_PI) * 10) <= imagesx($distortion_im) && (int)($i+20+cos($j/$this -> img_h * 2 * M_PI) * 10) >=0 ) {
                        imagesetpixel ($distortion_im, (int)($i+10+cos($j/$this -> img_h * 2 * M_PI - M_PI * 0.4) * $dis_range), $j, $rgb);
                    }
                }else{
                    if( (int)($i+40+sin($j/$this -> img_h * 2 * M_PI) * 10) <= imagesx($distortion_im) && (int)($i+20+sin($j/$this -> img_h * 2 * M_PI) * 10) >=0 ) {
                        imagesetpixel ($distortion_im, (int)($i+10+sin($j/$this -> img_h * 2 * M_PI - M_PI * 0.4) * $dis_range), $j, $rgb);
                    }
                }
            }
        }

        // 干擾像素
        for($i = 0; $i < $this -> int_pixel_num; $i++){
            $rand_color_pixel = $color;
            imagesetpixel($distortion_im, mt_rand() % $this -> img_w + 20, mt_rand() % $this -> img_h, $rand_color_pixel);
        }

        // 繪製邊框
        if($this -> border){
            $border_color_line = $color;
            imageline($distortion_im, 0, 0, $this -> img_w, 0, $border_color_line); // 上橫
            imageline($distortion_im, 0, 0, 0, $this -> img_h, $border_color_line); // 左豎
            imageline($distortion_im, 0, $this -> img_h-1, $this -> img_w, $this -> img_h-1, $border_color_line); // 下橫
            imageline($distortion_im, $this -> img_w-1, 0, $this -> img_w-1, $this -> img_h, $border_color_line); // 右豎
        }

        imageantialias($distortion_im, true); // 消除鋸齒

        $time = time();
        $_SESSION['vCode'] = $v_code."|".$time; // 把驗證碼與時間賦與給 $_SESSION[vCode], 時間欄位可以驗證��否超時

        // 生成圖像給瀏覽器
        if (function_exists("imagegif")) {
            header ("Content-type: image/gif");
            imagegif($distortion_im);
        }else if (function_exists("imagepng")) {
            header ("Content-type: image/png");
            imagepng($distortion_im);
        }else if (function_exists("imagejpeg")) {
            header ("Content-type: image/jpeg");
            imagejpeg($distortion_im, "", 80);
        }else if (function_exists("imagewbmp")) {
            header ("Content-type: image/vnd.wap.wbmp");
            imagewbmp($distortion_im);
        }else{
          die("No Image Support On This Server !");
        }

        imagedestroy($im);
        imagedestroy($distortion_im);
    }
}
?>