CakePHP Captcha Plugin

Bot Detect using Image captcha, Math captcha and Google-recaptcha for CakePHP 3

Why to use this plugin?

• To display Google Recaptcha / Image Captcha / Math Challenge for web forms

This CakePHP Captcha plugin requires CakePHP 3.6+.

Quick Features

• No Custom Code required.
• Quick install. Just add 3 lines, on each in Controller, Model and View.
• Works as Model Validation.
• Multiple Captchas on single page.
• Multiple Demo available.
• Demo available as CakePHP Plugin.

Installation

composer require inimist/cakephp-captcha

and

bin/cake plugin load Captcha -b -r

Implementation

1. Load Captcha plugin.

   If you ran bin/cake plugin load Captcha -b -r above skip this step.

   Place Plugin::load('Captcha'); in your application's Application.php or bootstrap.php file.

2. Load Capthca component

   Place $this->loadComponent('Captcha.Captcha'); in your controllerr's initialize function

   OR

   Load Captcha component on the fly, in the particular controller action function. For example in the signup() action:

   $this->loadComponent('Captcha.Captcha'); //or load on the fly!$

3. Add Behavior to your Model/Table

   Place $this->addBehavior('Captcha.Captcha', ['field'=>'<fieldname>']) in your Model (Table class) Note: If you use Google Recaptcha add "secret" option with its value which you get from Google. Also, add Google site key in the view file.

4. Create an input field in your view's form as:

   echo $this->Captcha->create('<fieldname>', $options);

5. In your controller in which your form data is processed, place (required with image and math catpcha):

   $this->Users->setCaptcha('<fieldname>', $this->Captcha->getCode('<fieldname>'));

   just before patching entity. For example:

   $this->Users->setCaptcha('securitycode', $this->Captcha->getCode('securitycode'));
   $user = $this->Users->patchEntity($user, $this->request->data);
   

A fully working demo can be found here. You can install a fully working demo as a plugin from here.

Settings

The best place for settings is your_apps/config/app.php file. Create a new key named "Captcha" and specify settings there.

'Captcha' => [
    'type' => 'recaptcha',
    'sitekey' => 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
    'secret' => 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
    //'clabel' => 'Enter code',
    //'reload_txt' => 'Reload??'
]

More examples

Options:

$options['width']=150;
$options['height']=50;
$options['theme']='default';
echo $this->Captcha->create('captcha_input_field_name', $options);

Multiple Captchas on same page:

//form 1
$options1['width']=150;
$options1['height']=50;
echo $this->Captcha->create('captcha_input_field_name1', $options1);

//form 2, A math captcha, anywhere on the page
$options2['type']='math';
echo $this->Captcha->create('captcha_input_field_name2', $custom2);

Options for view template. Ex: $this->Captcha->create('field_name', $options):

• field: field name (Optional. Default "captcha")
• type: recaptcha/image/math (Optional: Default "image")
• width: width of image captcha (Optional. Applies to type "image" only)
• height: height of image captcha (Optional. Applies to type "image" only)
• theme: default/random image captcha color pattern (Optional. Applies to type "image" only ; default "default")
• length: number of characters in image captcha (Optional. Applies to type "image" only)
• angle: angle of rotation for characters in image captcha (Optional. Applies to type "image" only)
• fontAdjustment: Font size for Image Captcha (Optional. Applies to type "image" only)
• reload_txt: Reload Captcha Text (Optional)
• clabel: Label for Image Captcha field (Optional)
• mlabel: Label for Math Captcha field (Optional)
• sitekey: Googel Recaptcha Sitekey (Required. Applies to type "recatpcha" only)

(All above options can also be set from controller. Ex: $this->loadComponent('Captcha.Captcha', $options))

**Options for model. Ex: $this->addBehavior('Captcha.Captcha', $options);

• field: field name (optional: default "captcha")
• secret: Googel Recaptcha Secret (required for type "recatpcha")

Known Issues:

1. Headers already sent issue. The component uses php's header() function to send or generate captcha image as raw HTML output. Make sure there is no output generated before the create() function in your component. It is common error to have spaces, tags or empty space in your files which would cause rending no image in the captcha.

2. GD library and True Type Font (TTF) support extensions are enabled in PHP.

3. This captcha script uses three random font faces, anonymous, droidsans and ubuntu to generate fonts in the captcha images. These font faces are placed in the captcha/src/Lib/Fonts of this download. I have seen that, sometimes, these font files get corrupted during downloads. If you see font not found error in your error logs and captcha are failed to generate, try downloading these font faces from their respective sources and replace them in the mentioned folder. You can also use different font families by placing them Fonts folder and referencing them in the CaptchaComponent.php component file.