vue-driven-cloud-storage/backend/auth.js

const jwt = require('jsonwebtoken');
const { UserDB } = require('./database');

// JWT密钥（必须在环境变量中设置）
const JWT_SECRET = process.env.JWT_SECRET || 'your-secret-key-change-in-production';

// 安全检查：验证JWT密钥配置
const DEFAULT_SECRETS = [
  'your-secret-key-change-in-production',
  'your-secret-key-change-in-production-PLEASE-CHANGE-THIS'
];

if (DEFAULT_SECRETS.includes(JWT_SECRET)) {
  const errorMsg = `
╔═══════════════════════════════════════════════════════════════╗
║                    ⚠️  安全警告  ⚠️                            ║
╠═══════════════════════════════════════════════════════════════╣
║  JWT_SECRET 使用默认值，存在严重安全风险！                    ║
║                                                               ║
║  请立即设置环境变量 JWT_SECRET                                ║
║  生成随机密钥:                                                ║
║  node -e "console.log(require('crypto').randomBytes(32).toString('hex'))"
║                                                               ║
║  在 backend/.env 文件中设置:                                  ║
║  JWT_SECRET=你生成的随机密钥                                  ║
╚═══════════════════════════════════════════════════════════════╝
  `;

  if (process.env.NODE_ENV === 'production') {
    console.error(errorMsg);
    throw new Error('生产环境必须设置 JWT_SECRET！');
  } else {
    console.warn(errorMsg);
  }
}

console.log('[安全] JWT密钥已配置');

// 生成JWT Token
function generateToken(user) {
  return jwt.sign(
    {
      id: user.id,
      username: user.username,
      is_admin: user.is_admin
    },
    JWT_SECRET,
    { expiresIn: '7d' }
  );
}

// 验证Token中间件
function authMiddleware(req, res, next) {
  // 从请求头、cookie或URL参数中获取token
  const token = req.headers.authorization?.replace('Bearer ', '') || req.cookies?.token || req.query?.token;

  if (!token) {
    return res.status(401).json({
      success: false,
      message: '未提供认证令牌'
    });
  }

  try {
    const decoded = jwt.verify(token, JWT_SECRET);
    const user = UserDB.findById(decoded.id);

    if (!user) {
      return res.status(401).json({
        success: false,
        message: '用户不存在'
      });
    }

    if (user.is_banned) {
      return res.status(403).json({
        success: false,
        message: '账号已被封禁'
      });
    }

    if (!user.is_active) {
      return res.status(403).json({
        success: false,
        message: '账号未激活'
      });
    }

    // 将用户信息附加到请求对象（包含所有存储相关字段）
    req.user = {
      id: user.id,
      username: user.username,
      email: user.email,
      is_admin: user.is_admin,
      has_ftp_config: user.has_ftp_config,
      ftp_host: user.ftp_host,
      ftp_port: user.ftp_port,
      ftp_user: user.ftp_user,
      ftp_password: user.ftp_password,
      http_download_base_url: user.http_download_base_url,
      // 存储相关字段（v2.0新增）
      storage_permission: user.storage_permission || 'sftp_only',
      current_storage_type: user.current_storage_type || 'sftp',
      local_storage_quota: user.local_storage_quota || 1073741824,
      local_storage_used: user.local_storage_used || 0
    };

    next();
  } catch (error) {
    if (error.name === 'TokenExpiredError') {
      return res.status(401).json({
        success: false,
        message: '令牌已过期'
      });
    }

    return res.status(401).json({
      success: false,
      message: '无效的令牌'
    });
  }
}

// 管理员权限中间件
function adminMiddleware(req, res, next) {
  if (!req.user || !req.user.is_admin) {
    return res.status(403).json({
      success: false,
      message: '需要管理员权限'
    });
  }
  next();
}

module.exports = {
  JWT_SECRET,
  generateToken,
  authMiddleware,
  adminMiddleware
};