https://github.com/jacopovalanzano/php-captcha

Portable Class. One file. Great for simple projects.
https://github.com/jacopovalanzano/php-captcha

captcha php recaptcha

Last synced: 6 months ago
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Portable Class. One file. Great for simple projects.

• Host: GitHub
• URL: https://github.com/jacopovalanzano/php-captcha
• Owner: jacopovalanzano
• License: mit
• Archived: true
• Created: 2021-06-20T23:46:14.000Z (about 5 years ago)
• Default Branch: main
• Last Pushed: 2022-05-06T23:36:00.000Z (about 4 years ago)
• Last Synced: 2025-06-09T05:48:06.337Z (about 1 year ago)
• Topics: captcha, php, recaptcha
• Language: PHP
• Homepage:
• Size: 741 KB
• Stars: 7
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          


# PHP Captcha

Portable PHP class for creating simple captchas.

One file. Great for simple projects.

![captcha1](https://i.imgur.com/CakXgDj.gif)

![captcha2](https://i.ibb.co/B6tZc0t/ezgif-4-5d353765b4.gif)

**NOTE**: this captcha is not a final solution to combat bots, but will stop avid and raging attackers.

For comparison, below is an example of a *captcha* used by **tesla.com**:

![tesla-captcha](https://i.imgur.com/tkcogKy.png)

Microsoft ([live.com](live.com)):

![live.com-captcha](https://i.imgur.com/Yy9qxbk.png)

## Installation

Install with composer, or use the contents of the **src** folder.

```bash  

composer require jacopovalanzano/php-captcha  

```  

Requires PHP ^5.4 and [PHP-GD](https://www.php.net/manual/en/book.image.php).

## Usage

The captcha is a binary jpeg image, it can be rendered with the "image/jpeg" content-type header.

```php  

    // Create a new Captcha  

    $captcha = new Captcha("My super difficult to read string.");  

  

    // Add 3 lines over and 3 behind the text,  

    // then build the image.  

    $captcha->linesFront(3)->linesBack(3)->build(175,50); // width, height  

  

    // Returns a string containing the captcha passphrase  

    $captcha->getPassphrase(); // Returns "My super difficult to read string."  

  

    // Renders the captcha.  

    $captcha->out();  

  

```  

## Example

A simple example to explain the process of dispatching/retrieving the captcha and its passphrase:

```php  

    // This file represents the "www.example.com/get_captcha_image" url that generates our captcha  

   

    // ...      

  

    // A list of words  

    $attributes = [ "easy", "green", "digital" ];  

  

    // One more list of words  

    $nouns = [ "compare", "dungeon", "clip" ];  

  

    // Compose a phrase  

    $words = $attributes[array_rand($attributes)]." ".$nouns[array_rand($nouns)];  

  

    // Create a new captcha with some random words  

    $captcha = new Captcha($words);  

  

    // Add 2 lines over and 5 behind the text,  

    // then build the image.  

    $captcha->linesFront(2)->linesBack(5)->build(175,50); // width, height  

  

    // Save the captcha passphrase to session, so it can be retrieved later...   

    $_SESSION["captcha_passphrase"] = $captcha->getPassphrase();  

  

    // Render the actual captcha image  

    $captcha->out();  

```  

An example of a form you need to validate, like a login form:

```html  

  

  

  

  

  

  

  

  

  

```

Or 

```

echo '';

```

Match ```$_SESSION["captcha_passphrase"]```

against the value passed from the input "captcha_passphrase" in the example above, eg:

```php  

    // Compare the captcha passphrase with the one submitted  

    if($_POST["captcha_passphrase"] !== $_SESSION["captcha_passphrase"]) {  

        die("Wrong captcha!");  

    }  

```  

## Tests

Tested with [GNU ocrad](https://www.gnu.org/software/ocrad/) and [Xevil](http://xevil.net)

![xevil](https://i.imgur.com/xnlZsWV.gif)

## Contributing

Pull requests are welcome.

## License

[MIT](https://github.com/jacopovalanzano/php-captcha/blob/main/LICENSE)