<?php
/**
* This file is part of Aksara CMS, both framework and publishing
* platform.
*
* @author Aby Dahana <abydahana@gmail.com>
* @copyright (c) Aksara Laboratory <https://aksaracms.com>
* @license MIT License
*
* This source file is subject to the MIT license that is bundled
* with this source code in the LICENSE.txt file.
*
* When the signs is coming, those who don't believe at "that time"
* have only two choices, commit suicide or become brutal.
*/
use GdImage;
use Throwable;
if (! function_exists('create_captcha')) {
/**
* Create CAPTCHA
*
* @param array|string $data Data for the CAPTCHA or word
* @param string $img_path Path to create the image in
* @param string $img_url URL to the CAPTCHA image folder
* @param string $font_path Server path to font
*/
function create_captcha(array|string $data = [], string $img_path = '', string $img_url = '', string $font_path = ''): array|bool
{
$defaults = [
'word' => '',
'img_path' => $img_path,
'img_url' => $img_url,
'img_width' => 150,
'img_height' => 35,
'font_path' => $font_path,
'expiration' => 7200,
'word_length' => 6,
'font_size' => 16,
'img_id' => 'captcha-' . uniqid(),
'pool' => '23456789abcdefghjkmnpqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ',
'colors' => [
'background' => [255, 255, 255],
'border' => [200, 200, 200],
'text' => [50, 50, 50],
'grid' => [235, 235, 235]
]
];
// Merge configuration
$config = is_array($data) ? array_merge($defaults, $data) : $defaults;
// Check for GD extension and basic requirements
if (! extension_loaded('gd') || empty($config['img_path']) || ! is_dir($config['img_path']) || ! is_writable($config['img_path'])) {
return false;
}
// -----------------------------------
// 1. Remove old images (Cleanup)
// -----------------------------------
$now = microtime(true);
if ($handle = @opendir($config['img_path'])) {
while (false !== ($filename = readdir($handle))) {
if (preg_match('/^(\d+\.\d+)\.png$/', $filename, $matches)) {
if (($matches[1] + $config['expiration']) < $now) {
@unlink($config['img_path'] . $filename);
}
}
}
closedir($handle);
}
// -----------------------------------
// 2. Generate Word
// -----------------------------------
$word = $config['word'];
if (empty($word)) {
$word = '';
$pool_length = strlen($config['pool']);
for ($i = 0; $i < $config['word_length']; $i++) {
try {
$word .= $config['pool'][random_int(0, $pool_length - 1)];
} catch (Throwable $e) {
$word .= $config['pool'][mt_rand(0, $pool_length - 1)];
}
}
}
// -----------------------------------
// 3. Image Creation (With Error Trapping)
// -----------------------------------
try {
$im = imagecreatetruecolor($config['img_width'], $config['img_height']);
// Validate that $im is actually a GdImage object (solves Intelephense P1007)
if (! $im instanceof GdImage) {
return false;
}
// Assign colors
$colors = [];
foreach ($config['colors'] as $key => $rgb) {
$colors[$key] = imagecolorallocate($im, $rgb[0], $rgb[1], $rgb[2]);
}
// Create background
imagefilledrectangle($im, 0, 0, $config['img_width'], $config['img_height'], $colors['background']);
// -----------------------------------
// 4. Distortions (Grid & Noise)
// -----------------------------------
// Draw subtle grid
for ($i = 0; $i < $config['img_width']; $i += 15) {
imageline($im, $i, 0, $i, $config['img_height'], $colors['grid']);
}
for ($i = 0; $i < $config['img_height']; $i += 15) {
imageline($im, 0, $i, $config['img_width'], $i, $colors['grid']);
}
// Add random noise pixels
for ($i = 0; $i < 60; $i++) {
imagesetpixel($im, mt_rand(0, $config['img_width']), mt_rand(0, $config['img_height']), $colors['text']);
}
// -----------------------------------
// 5. Write Text
// -----------------------------------
$use_font = (! empty($config['font_path']) && file_exists($config['font_path']));
$x = 12;
$length = strlen($word);
for ($i = 0; $i < $length; $i++) {
if ($use_font) {
$angle = mt_rand(-15, 15);
$y = mt_rand((int) ($config['img_height'] / 1.5), $config['img_height'] - 5);
imagettftext($im, $config['font_size'], $angle, (int) $x, (int) $y, $colors['text'], $config['font_path'], $word[$i]);
} else {
$y = mt_rand(2, (int) ($config['img_height'] / 4));
imagestring($im, 5, (int) $x, (int) $y, $word[$i], $colors['text']);
}
$x += ($config['img_width'] - 20) / $length;
}
// Add Border
imagerectangle($im, 0, 0, $config['img_width'] - 1, $config['img_height'] - 1, $colors['border']);
// -----------------------------------
// 6. Output & Cleanup
// -----------------------------------
$img_filename = $now . '.png';
$img_url = rtrim($config['img_url'], '/') . '/';
// Generate PNG file
if (! imagepng($im, $config['img_path'] . $img_filename)) {
return false;
}
// PHP 8+ Garbage Collection takes care of the GdImage object.
// Setting to null is the modern way to explicitly free it.
$im = null;
return [
'word' => $word,
'time' => $now,
'image' => '<img id="' . $config['img_id'] . '" src="' . $img_url . $img_filename . '" style="width: ' . $config['img_width'] . 'px; height: ' . $config['img_height'] . 'px; border: 0;" alt="CAPTCHA" />',
'filename' => $img_filename
];
} catch (Throwable $e) {
// Gracefully fail if something goes wrong during image processing
return false;
}
}
}
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