Enhance CDN Infrastructure: Secure Server and File Management

.gitignore

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+node_modules/
+dist/
+.env
+__pycache__/
+*.log
+.DS_Store
+coverage/
+.nyc_output/

src/config/__tests__/cdn.test.ts

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+import { describe, it, expect } from 'vitest';
+import path from 'path';
+import { CDN_CONFIG } from '../cdn';
+
+describe('CDN Configuration', () => {
+  const rootDir = CDN_CONFIG.ROOT_DIR;
+
+  it('should have a valid root directory', () => {
+    expect(rootDir).toBeTruthy();
+    expect(path.isAbsolute(rootDir)).toBe(true);
+    expect(path.basename(rootDir)).toBe('cdn_files');
+  });
+
+  describe('isValidPath', () => {
+    it('should allow paths within the CDN directory', () => {
+      expect(CDN_CONFIG.isValidPath('file.txt')).toBe(true);
+      expect(CDN_CONFIG.isValidPath('subdir/file.txt')).toBe(true);
+    });
+
+    it('should prevent directory traversal', () => {
+      expect(CDN_CONFIG.isValidPath('../outside.txt')).toBe(false);
+      expect(CDN_CONFIG.isValidPath('/etc/passwd')).toBe(false);
+      expect(CDN_CONFIG.isValidPath('../../sensitive.txt')).toBe(false);
+    });
+  });
+
+  describe('getFullPath', () => {
+    it('should return full path for valid relative paths', () => {
+      const fullPath = CDN_CONFIG.getFullPath('example.txt');
+      expect(fullPath).toBe(path.resolve(rootDir, 'example.txt'));
+    });
+
+    it('should throw error for invalid paths', () => {
+      expect(() => CDN_CONFIG.getFullPath('../outside.txt'))
+        .toThrow('Invalid file path');
+    });
+  });
+});

src/config/cdn.ts

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+import path from 'path';
+
+/**
+ * Configuration for CDN file storage
+ */
+export const CDN_CONFIG = {
+  /**
+   * Root directory for CDN files
+   * Uses an absolute path resolved from the project root
+   */
+  ROOT_DIR: path.resolve(process.cwd(), 'cdn_files'),
+
+  /**
+   * Validate if the provided path is within the CDN directory
+   * @param filePath - Path to validate
+   * @returns boolean indicating if the path is valid
+   */
+  isValidPath(filePath: string): boolean {
+    const normalizedPath = path.normalize(filePath);
+    const resolvedPath = path.resolve(this.ROOT_DIR, normalizedPath);
+    return resolvedPath.startsWith(this.ROOT_DIR);
+  },
+
+  /**
+   * Get the full path for a file in the CDN
+   * @param relativePath - Relative path within the CDN directory
+   * @returns Full absolute path to the file
+   */
+  getFullPath(relativePath: string): string {
+    if (!this.isValidPath(relativePath)) {
+      throw new Error('Invalid file path');
+    }
+    return path.resolve(this.ROOT_DIR, relativePath);
+  }
+};