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我已经使用验证码创建了一个注册表单，但我需要验证码可以在客户端而不是服务器端工作，所以我想开发在客户端工作的 recaptcha 文件，任何人都可以帮助我。提前致谢

我的验证码是 

session_start();
//Settings: You can customize the captcha here
$image_width = 120;
$image_height = 40;
$characters_on_image = 6;
$font = './monofont.ttf';

//The characters that can be used in the CAPTCHA code.
//avoid confusing characters (l 1 and i for example)
$possible_letters = '23456789bcdfghjkmnpqrstvwxyz';
$random_dots = 0;
$random_lines = 20;
$captcha_text_color="0x142864";
$captcha_noice_color = "0x142864";

$code = ''; 

$i = 0;
while ($i < $characters_on_image) { 
    $code .= substr($possible_letters, mt_rand(0, strlen($possible_letters)-1), 1);
    $i++;
}   

$font_size = $image_height * 0.75;
$image = @imagecreate($image_width, $image_height); 

/* setting the background, text and noise colours here */
$background_color = imagecolorallocate($image, 255, 255, 255);

$arr_text_color = hexrgb($captcha_text_color);
$text_color = imagecolorallocate($image, $arr_text_color['red'], 
        $arr_text_color['green'], $arr_text_color['blue']);

$arr_noice_color = hexrgb($captcha_noice_color);
$image_noise_color = imagecolorallocate($image, $arr_noice_color['red'], 
        $arr_noice_color['green'], $arr_noice_color['blue']);   

/* generating the dots randomly in background */
for( $i=0; $i<$random_dots; $i++ ) {
    imagefilledellipse($image, mt_rand(0,$image_width),
    mt_rand(0,$image_height), 2, 3, $image_noise_color);
}   

/* generating lines randomly in background of image */
for( $i=0; $i<$random_lines; $i++ ) {
    imageline($image, mt_rand(0,$image_width), mt_rand(0,$image_height),
    mt_rand(0,$image_width), mt_rand(0,$image_height), $image_noise_color);
}   

/* create a text box and add 6 letters code in it */
$textbox = imagettfbbox($font_size, 0, $font, $code); 
$x = ($image_width - $textbox[4])/2;
$y = ($image_height - $textbox[5])/2;
imagettftext($image, $font_size, 0, $x, $y, $text_color, $font , $code);    

/* Show captcha image in the page html page */
header('Content-Type: image/jpeg');// defining the image type to be shown in browser widow
imagejpeg($image);//showing the image
imagedestroy($image);//destroying the image instance
$_SESSION['6_letters_code'] = $code;

function hexrgb ($hexstr)
{
    $int = hexdec($hexstr); 
    return array("red" => 0xFF & ($int >> 0x10),
               "green" => 0xFF & ($int >> 0x8),
               "blue" => 0xFF & $int);
}
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2 回答 2

1

您无法在 PHP 中实现客户端重新验证。任何在客户端（用 JavaScript 或其他方式）实现的验证码都很容易被破解，所以这不是一个好主意。

于 2012-08-01T08:46:23.707 回答
0

验证码验证无法在客户端完成。它只能在服务器端完成..

于 2012-12-20T12:20:10.513 回答