Question

我有以下验证码：

<?php

class CaptchaView extends View
{
    private $fontsDir = 'captcha_resources/fonts/';
    private $backgroundsDir = 'captcha_resources/backgrounds/';
    private static $dirCache = array();

    public function render($controller)
    {
        $code = $controller->viewVars["code"];

        /**
         * The next part is orginnaly written by ted from mastercode.nl and modified for using in this mod.
         **/

        header("content-type:image/png");
        header('Cache-control: no-cache, no-store');

        $width = 100;
        $height = 30;

        $img = imagecreatefrompng(self::backgroundImage());

        // add noise
        for ($i = 0; $i < 1; $i++) {
            $horizontal_progress = 0;
            $vertical_pos = rand(1, $height / 2);
            do {
                $horizontal_step_size = floor(rand(1, $width / 5));

                imageline($img, $horizontal_progress, $vertical_pos, ($horizontal_progress += $horizontal_step_size), ($vertical_pos = rand(1, $height)), self::color("tekst"));
            } while ($horizontal_progress < $width);
        }

        $background = imagecolorallocate($img, self::color("bg"), self::color("bg"), self::color("bg"));

        for ($g = 0; $g < 30; $g++) {
            $t = rand(10, 20);
            $t = $t[0];

            $ypos = rand(0, $height);
            $xpos = rand(0, $width);

            $kleur = imagecolorallocate($img, self::color("bgtekst"), self::color("bgtekst"), self::color("bgtekst"));

            imagettftext($img, self::size(), self::move(), $xpos, $ypos, $kleur, self::font(), $t);
        }

        $stukje = $width / (strlen($code) + 3) + 5;

        for ($j = 0; $j < strlen($code); $j++) {
            $tek = $code[$j];
            $ypos = rand(23, 27);
            $xpos = $stukje * ($j + 1) - 5;

            $color2 = imagecolorallocate($img, self::color("tekst"), self::color("tekst"), self::color("tekst"));

            imagettftext($img, self::size(), self::move(), $xpos, $ypos, $color2, self::font(), $tek);
        }

        imagepng($img);
        imagedestroy($img);
    }
    /**
     * Some functions :)
     * Also orginally written by mastercode.nl
     **/

    /**
     * Function to create a random color
     * @auteur mastercode.nl
     * @param $type string Mode for the color
     * @return int
     **/
    private static function color($type)
    {
        switch ($type) {
            case "bg":
                $color = rand(224, 255);
                break;

            case "tekst":
                $color = rand(0, 127);
                break;

            case "bgtekst":
                $color = rand(200, 224);
                break;

            default:
                $color = rand(0, 255);
                break;
        }
        return $color;
    }

    /**
     * Function to ranom the size
     * @auteur mastercode.nl
     * @return int
     **/
    private static function size()
    {
        return rand(18, 22);
    }

    /**
     * Function to random the posistion
     * @auteur mastercode.nl
     * @return int
     **/
    private static function move()
    {
        return rand(-22, 22);
    }

    /**
     * Function to return a ttf file from fonts map
     * @auteur mastercode.nl
     * @return string
     **/
    function randomFileByExt($dir, $ext)
    {
        $f = opendir($dir);

        if (empty(self::$dirCache[$dir])) {
            $ar = array();
            while (($file = @readdir($f)) !== false) {
                if (!in_array($file, array('.', '..')) && substr_compare($file, $ext, -strlen($ext)) == 0) {
                    $ar[] = $file;
                }
            }

            self::$dirCache[$dir] = $ar;
        } else {
            $ar = self::$dirCache[$dir];
        }

        if (count($ar)) {
            $i = rand(0, (count($ar) - 1));
            return $dir . $ar[$i];
        }
    }

    private function backgroundImage()
    {
        return self::randomFileByExt(Config::get("VIEWS_PATH") . $this->backgroundsDir, ".png");
    }

    private function font()
    {
        return self::randomFileByExt(Config::get("VIEWS_PATH") . $this->fontsDir, ".ttf");
    }
}

实际上它显示4个字母背景不受干扰

我希望阻止一些垃圾邮件机器人我认为修改代码以增加安全性增加字母数量你能告诉我如何修改它来显示6个字母而不是4个字母吗？

Answer 1

1）最佳解决方案是实现现有的Captcha，如reCaptcha等。

2）修改代码以推送6而不是4个字母编辑部分代码，如下所示：

$stukje = $width / (strlen($code) + 5) + 5; //instead of  "+3) +5;"

应该做的伎俩，但我无法测试它，因为我不知道它使用的是什么模式（什么是CMS，PHP框架......）

captcha修改六个字母

1 个答案: