/plugins/captcha/captcha.php

<?php

////////////////////////////////////////////////////////////////////////////

//                              SnowCMS v2.0                              //

//                           By the SnowCMS Team                          //

//                             www.snowcms.com                            //

//            Released under the Microsoft Reciprocal License             //

//                 www.opensource.org/licenses/ms-rl.html                 //

////////////////////////////////////////////////////////////////////////////

//                                                                        //

//       SnowCMS originally pawned by soren121 started in early 2008      //

//                                                                        //

////////////////////////////////////////////////////////////////////////////

//                                                                        //

//                  SnowCMS v2.0 began in November 2009                   //

//                                                                        //

////////////////////////////////////////////////////////////////////////////

//                       File version: SnowCMS 2.0                        //

////////////////////////////////////////////////////////////////////////////



if(!defined('INSNOW'))

{

	die('Nice try...');

}



// Title: Display CAPTCHA



/*

	Function: captcha_display



	Renders a CAPTCHA image, for those oh-so-fun CAPTCHA tests.



	Parameters:

		none



	Returns:

		void - Nothing is returned by this function.



	Note:

		This function is overloadable.

*/

function captcha_display()

{

	global $api, $settings;



	$api->run_hooks('captcha_display');



	# Now, let's make sure that the server supports this, it uses GD...

	if(!function_exists('imagecreate'))

	{

		die(l('Your server configuration does not support the <a href="%s">GD extension</a>.', 'http://www.php.net/gd'));

	}

	# We need an identifier for this CAPTCHA image.

	elseif(empty($_GET['id']))

	{

		die(l('No CAPTCHA identifier was supplied, could not complete your request.'));

	}



	# Do you have GD2? Then we can use imagecreatetruecolor.

	$gd_info = gd_info();

	$gd_version = substr($gd_info['GD Version'], strpos($gd_info['GD Version'], '(') + 1, strpos($gd_info['GD Version'], ' ', strpos($gd_info['GD Version'], '(')) - (strpos($gd_info['GD Version'], '(') + 1));

	if(version_compare($gd_version, '2') >= 0)

	{

		$image = imagecreatetruecolor($settings->get('captcha_width', 'int'), $settings->get('captcha_height', 'int'));

	}

	else

	{

		$image = imagecreate($settings->get('captcha_width', 'int'), $settings->get('captcha_height', 'int'));

	}



	# Make our background color.

	$background = imagecolorallocate($image, $api->apply_filters('captcha_bg_red', 255), $api->apply_filters('captcha_bg_green', 255), $api->apply_filters('captcha_bg_blue', 255));



	# Apply the color.

	imagefill($image, 0, 0, $background);



	# Let's make some noise!

	# In order to do so, let's make some random colors, shall we?

	$colors = array();

	for($i = 0; $i < 32; $i++)

	{

		$colors[] = imagecolorallocate($image, mt_rand(0, 255), mt_rand(0, 255), mt_rand(0, 255));

	}



	# Some background noise.

	$num_ellipses = mt_rand(10, 15);

	for($i = 0; $i < $num_ellipses; $i++)

	{

		imageellipse($image, mt_rand(0, $settings->get('captcha_width', 'int')), mt_rand(0, $settings->get('captcha_height', 'int')), mt_rand(1, 50), mt_rand(1, 25), $colors[array_rand($colors)]);

	}



	# Now for the text, 5-6 is usually good.

	$num_chars = $settings->get('captcha_num_chars', 'int');



	# The characters which we will use to put into the CAPTCHA.

	$chars = str_shuffle('ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789');



	$rand_str = '';

	for($i = 0; $i < $num_chars; $i++)

	{

		$rand_str .= $chars[mt_rand(0, strlen($chars) - 1)];

	}



	# Save it to their session, otherwise, this does no good!!!

	if(!isset($_SESSION['captcha_text']) || !is_array($_SESSION['captcha_text']))

	{

		$_SESSION['captcha_text'] = array();

	}



	$_SESSION['captcha_text'][$_GET['id']] = $rand_str;



	# TrueType font support? If so you are AWESOME.

	if(function_exists('imagettftext'))

	{

		$fonts = scandir(dirname(__FILE__). '/ttf/');

		foreach($fonts as $key => $font)

		{

			if(substr($font, strlen($font) - 3, strlen($font)) != 'ttf')

			{

				unset($fonts[$key]);

			}

		}



		for($i = 0, $x = 10; $i < $num_chars; $i++, $x += 30)

		{

			$size = ceil($settings->get('captcha_height', 'int') / 2) + mt_rand(-2, 2);

			$angle = mt_rand(-30, 30);

			$y = ceil($settings->get('captcha_height', 'int') / 2) + mt_rand(0, floor($settings->get('captcha_height', 'int') / 2) - 10);

			$fontfile = dirname(__FILE__). '/ttf/'. $fonts[array_rand($fonts)];



			imagettftext($image, $size, $angle, $x - 2, $y - 2, $colors[array_rand($colors)], $fontfile, $rand_str[$i]);

			imagettftext($image, $size, $angle, $x, $y, $colors[array_rand($colors)], $fontfile, $rand_str[$i]);

		}

	}

	else

	{

		# Dang... No TrueType support? It won't be as good, but it is possible.

		for($i = 0, $x = 10; $i < $num_chars; $i ++, $x += 30)

		{

			# Get the character image.

			$char_image = imagecreatefrompng(dirname(__FILE__). '/chars/'. strtoupper($rand_str[$i]). '.png');



			# Rotate the image.

			$char_image = imagerotate($char_image, mt_rand(-30, 30), imagecolortransparent($char_image, imagecolorallocate($char_image, 255, 255, 255)));



			# Copy it over.

			imagecopy($image, $char_image, $x, mt_rand(0, floor($settings->get('captcha_height', 'int') / 2) - 10), 0, 0, imagesx($char_image), imagesy($char_image));

			imagedestroy($char_image);

		}

	}



	# Let's create a grid

	$vertical = $settings->get('captcha_width', 'int') / 20;

	for($i = 0; $i < $vertical; $i++)

	{

		imageline($image, (20 * $i) + mt_rand(-5, 5), 0, (20 * $i) + mt_rand(-5, 5), $settings->get('captcha_height', 'int'), $colors[array_rand($colors)]);

	}



	$horizontal = $settings->get('captcha_height', 'int') / 10;

	for($i = 0; $i < $horizontal; $i++)

	{

		imageline($image, 0, (10 * $i) + mt_rand(-5, 5), $settings->get('captcha_width', 'int'), (10 * $i) + mt_rand(-5, 5), $colors[array_rand($colors)]);

	}



	# Remove any previous headers so we can send out new ones!

	if(ob_get_length() > 0)

	{

		ob_clean();

	 }



	header('Pragma: no-cache');

	header('Content-Type: image/png');



	# Display the image.

	imagepng($image);



	# Destroy! Destory! >:D

	imagedestroy($image);

	exit;

}

?>