fix(captcha): Fix Gregwar CaptchaBuilder for PHP 8.1

Author: julienloizelet

src/Bouncer.php

@@ -5,7 +5,7 @@
 require_once __DIR__.'/templates/captcha.php';
 require_once __DIR__.'/templates/access-forbidden.php';
 
-use Gregwar\Captcha\CaptchaBuilder;
+use CrowdSecBouncer\Fixes\Gregwar\Captcha\CaptchaBuilder;
 use Gregwar\Captcha\PhraseBuilder;
 use IPLib\Factory;
 use Monolog\Handler\NullHandler;

src/Fixes/Gregwar/Captcha/CaptchaBuilder.php

@@ -0,0 +1,78 @@
+<?php
+
+
+namespace CrowdSecBouncer\Fixes\Gregwar\Captcha;
+
+use Gregwar\Captcha\CaptchaBuilder as GregwarCaptchaBuilder;
+
+/**
+ * Override to fix "implicit conversion error on PHP  8.1"
+ * @see https://github.com/crowdsecurity/php-cs-bouncer/issues/62 and
+ * @see https://github.com/Gregwar/Captcha/pull/101/files
+ *
+ */
+class CaptchaBuilder extends GregwarCaptchaBuilder {
+
+
+    /**
+     * Writes the phrase on the image
+     */
+    protected function writePhrase($image, $phrase, $font, $width, $height)
+    {
+        $length = mb_strlen($phrase);
+        if ($length === 0) {
+            return \imagecolorallocate($image, 0, 0, 0);
+        }
+
+        // Gets the text size and start position
+        $size = (int) round($width / $length) - $this->rand(0, 3) - 1;
+        $box = \imagettfbbox($size, 0, $font, $phrase);
+        $textWidth = $box[2] - $box[0];
+        $textHeight = $box[1] - $box[7];
+        $x = (int) round(($width - $textWidth) / 2);
+        $y = (int) round(($height - $textHeight) / 2) + $size;
+
+        if (!$this->textColor) {
+            $textColor = array($this->rand(0, 150), $this->rand(0, 150), $this->rand(0, 150));
+        } else {
+            $textColor = $this->textColor;
+        }
+        $col = \imagecolorallocate($image, $textColor[0], $textColor[1], $textColor[2]);
+
+        // Write the letters one by one, with random angle
+        for ($i=0; $i<$length; $i++) {
+            $symbol = mb_substr($phrase, $i, 1);
+            $box = \imagettfbbox($size, 0, $font, $symbol);
+            $w = $box[2] - $box[0];
+            $angle = $this->rand(-$this->maxAngle, $this->maxAngle);
+            $offset = $this->rand(-$this->maxOffset, $this->maxOffset);
+            \imagettftext($image, $size, $angle, $x, $y + $offset, $col, $font, $symbol);
+            $x += $w;
+        }
+
+        return $col;
+    }
+
+
+    /**
+     * Returns a random number or the next number in the
+     * fingerprint
+     */
+    protected function rand($min, $max)
+    {
+        if (!is_array($this->fingerprint)) {
+            $this->fingerprint = array();
+        }
+
+        if ($this->useFingerprint) {
+            $value = current($this->fingerprint);
+            next($this->fingerprint);
+        } else {
+            $value = mt_rand((int) $min, (int) $max);
+            $this->fingerprint[] = $value;
+        }
+
+        return $value;
+    }
+
+}