first commit

admin/captcha.php

@@ -0,0 +1,60 @@
+<?php
+session_start();
+
+// 生成验证码
+$code = '';
+$chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
+for ($i = 0; $i < 4; $i++) {
+    $code .= $chars[rand(0, strlen($chars) - 1)];
+}
+
+$_SESSION['captcha'] = $code;
+
+// 创建图片
+$width = 100;
+$height = 40;
+$image = imagecreate($width, $height);
+
+// 颜色定义
+$bg_color = imagecolorallocate($image, 245, 245, 245);
+$text_color = imagecolorallocate($image, 50, 50, 50);
+$line_color = imagecolorallocate($image, 200, 200, 200);
+$noise_color = imagecolorallocate($image, 180, 180, 180);
+
+// 填充背景
+imagefill($image, 0, 0, $bg_color);
+
+// 添加干扰线
+for ($i = 0; $i < 5; $i++) {
+    imageline($image, rand(0, $width), rand(0, $height), rand(0, $width), rand(0, $height), $line_color);
+}
+
+// 添加噪点
+for ($i = 0; $i < 50; $i++) {
+    imagesetpixel($image, rand(0, $width), rand(0, $height), $noise_color);
+}
+
+// 添加验证码文字
+for ($i = 0; $i < 4; $i++) {
+    $x = 15 + $i * 18;
+    $y = rand(8, 15);
+    $angle = rand(-15, 15);
+    
+    if (function_exists('imagettftext')) {
+        // 如果支持TTF字体
+        imagettftext($image, 16, $angle, $x, 25, $text_color, __DIR__ . '/arial.ttf', $code[$i]);
+    } else {
+        // 使用内置字体
+        imagestring($image, 5, $x, $y, $code[$i], $text_color);
+    }
+}
+
+// 输出图片
+header('Content-Type: image/png');
+header('Cache-Control: no-cache, no-store, must-revalidate');
+header('Pragma: no-cache');
+header('Expires: 0');
+
+imagepng($image);
+imagedestroy($image);
+?>