PHP Simple Captcha

A simple captcha package that fit to any type of web application built on php.

Sample

Requirement(s)

• PHP version from 5.6.* up to latest.

Install

• Recommended to install using Composer. Use the command below to install the package:

composer require lorddashme/php-simple-captcha

Usage

List of Available Functions

Function	Description
code(length);	Execute the generation of random code base on the given length. The default length is 5.
image();	Execute the generation of image and the content will be base on the code(length); function.
getCode();	To get the current code generated by the code(length); method. Ex. return value QwErTyx...
getImage();	To get the current image generated by the image(); function. Ex. return value data:image/png;base64,iVBORw0KGgoAA...
storeSession();	Use to store the generated values in the captcha session.
getSession();	Use to get the current stored session generated values in the captcha session. This is use to validate the generated code against the user organic inputed code. Ex. return value array('code' => '...')

• Basic usage:

<?php

include __DIR__  . '/vendor/autoload.php';

use LordDashMe\SimpleCaptcha\Captcha;

// Initialize the captcha class.
$captcha = new Captcha();
// Execute the random generation of code.
$captcha->code();
// Execute the image captcha rendering.
$captcha->image();

// The generated captcha code, something like "QwErTyx..."
echo $captcha->getCode();
// The generated captcha image that include the code above. 
// The output is base64 data image "data:image/png;base64,iVBORw0KGgoAA..."
echo $captcha->getImage();

• Also can be done by using the code below:

<?php

include __DIR__  . '/vendor/autoload.php';

use LordDashMe\SimpleCaptcha\Facade\Captcha;

// Initialize the facade captcha class.
Captcha::init();
// Execute the random generation of code.
Captcha::code();
// Execute the image captcha rendering.
Captcha::image();

// The generated captcha code, something like "QwErTyx..."
echo Captcha::getCode();
// The generated captcha image that include the code above.  
// The output is base64 data image "data:image/png;base64,iVBORw0KGgoAA..."
echo Captcha::getImage();

Captcha Session Usage

• The package also provided a simple way to validate the user input code, for example we have a login feature.

  • Login Page:

    • Initialize the Captcha class together with the code and image generation process.

    • Use the storeSession() to store the generated details in the captcha session.

    • The stored session details are essential for validating the user input later on.

    <?php
    
    // login.php
    
    include __DIR__  . '/vendor/autoload.php';
    
    use LordDashMe\SimpleCaptcha\Captcha;
    
    $captcha = new Captcha();
    $captcha->code();
    $captcha->image();
    $captcha->storeSession();
    
    ?>
    
    <form action="validate-login.php" method="POST">
    
      ...
    
      <img src="<?php echo $captcha->getImage(); ?>">
      <input type="text" name="user_captcha_code" value="">
    
      <input type="submit" value="Login">
    
    </form>

  • Validation Route:

    • We need to initialize again the Captcha class but now we don't need to initialize the code and image generation.

    • Validate the user inputed captcha code.

    <?php
    
    // validate-login.php
    
    include __DIR__  . '/vendor/autoload.php';
    
    use LordDashMe\SimpleCaptcha\Captcha;
    
    $captcha = new Captcha();
    $data = $captcha->getSession(); // return array( 'code' => 'QwErTyx...' )
    
    if ($_POST['user_captcha_code'] === $data['code']) {
        return 'Code is valid!';
    } else {
        return 'Code is invalid!';
    }

  • You may also check the sample in the root directory of the package that will show you the actual example of implementing captcha class.

Captcha Configuration

• To change the default config of the class:

<?php

include __DIR__  . '/vendor/autoload.php';

use LordDashMe\SimpleCaptcha\Captcha;
use LordDashMe\SimpleCaptcha\Facade\Captcha as CaptchaFacade;

$config = array(
    'session_name'       => 'ldm-simple-captcha',
    'session_index_name' => 'LDM_SIMPLE_CAPTCHA',
    'session_https'      => false,
    'session_http_only'  => true,
    'font_color'         => '#000',
    'font_size_min'      => 26,
    'font_size_max'      => 28,
    'angle_min'          => 0,
    'angle_max'          => 9,
    'shadow'             => true,
    'shadow_color'       => '#fff',
    'shadow_offset_x'    => -3,
    'shadow_offset_y'    => 1,
    'backgrounds' => array(
        'bg1.png',
        'bg2.png',
        'bg3.png',
        'bg4.png',
        'bg5.png',
        'bg6.png',
        'bg7.png',
        'bg8.png'
    ),
    'fonts' => array(
        'capsmall_clean.ttf'
    )
);

$captcha = new Captcha($config);

// Or you can use this style.

CaptchaFacade::init($config);

Tips

• Overriding the default config:

  • The backgrounds and fonts are tightly coupled in the directory structure of the package.

  • If you want to override the backgrounds and fonts you need to extends the Captcha class with your new sub class and override the protected methods of Captcha class for resources directory, backgroundsDirectoryPath() and fontsDirectoryPath.

    <?php
    
    include __DIR__  . '/vendor/autoload.php';
    
    use LordDashMe\SimpleCaptcha\Captcha;
    
    class MyNewCaptcha extends Captcha
    {
        public function __construct($config = array())
        {
            parent::__construct($config);
        }
    
        protected function backgroundsDirectoryPath()
        {
            return 'path/to/your/custom/backgrounds/';
        }
    
        protected function fontsDirectoryPath()
        {
            return 'path/to/your/custom/fonts/'; 
        }
    }

License

This package is open-sourced software licensed under the MIT license.