🔒 Add authentication middleware for secure access

code/websites/pokedex.online/server/middleware/auth.js

@@ -0,0 +1,122 @@
+/**
+ * Authentication Middleware
+ *
+ * Middleware for authenticating and authorizing requests using JWT tokens
+ */
+
+import { verifyToken } from '../utils/jwt-utils.js';
+
+/**
+ * Middleware to verify JWT token from Authorization header
+ * Sets req.user if token is valid
+ *
+ * @param {Object} options - Configuration options
+ * @param {string} options.secret - JWT secret for token verification
+ * @param {boolean} options.optional - If true, missing token is not an error (default: false)
+ * @returns {Function} Express middleware function
+ */
+export function authMiddleware({ secret, optional = false } = {}) {
+  return (req, res, next) => {
+    const authHeader = req.headers.authorization;
+    
+    if (!authHeader) {
+      if (optional) {
+        req.user = null;
+        return next();
+      }
+      return res.status(401).json({
+        error: 'Missing authorization header',
+        code: 'MISSING_AUTH_HEADER'
+      });
+    }
+
+    // Extract token from "Bearer <token>" format
+    const parts = authHeader.split(' ');
+    if (parts.length !== 2 || parts[0] !== 'Bearer') {
+      return res.status(401).json({
+        error: 'Invalid authorization header format. Expected: Bearer <token>',
+        code: 'INVALID_AUTH_FORMAT'
+      });
+    }
+
+    const token = parts[1];
+
+    try {
+      const decoded = verifyToken(token, secret);
+      req.user = decoded;
+      next();
+    } catch (err) {
+      const code = err.message.includes('expired') ? 'TOKEN_EXPIRED' : 'INVALID_TOKEN';
+      return res.status(401).json({
+        error: err.message,
+        code
+      });
+    }
+  };
+}
+
+/**
+ * Middleware to check if user has required permissions
+ *
+ * @param {string|string[]} requiredPermissions - Permission or array of permissions required
+ * @returns {Function} Express middleware function
+ */
+export function requirePermission(requiredPermissions) {
+  const permissions = Array.isArray(requiredPermissions)
+    ? requiredPermissions
+    : [requiredPermissions];
+
+  return (req, res, next) => {
+    if (!req.user) {
+      return res.status(403).json({
+        error: 'Forbidden: User not authenticated',
+        code: 'NOT_AUTHENTICATED'
+      });
+    }
+
+    const userPermissions = req.user.permissions || [];
+    const hasPermission = permissions.some(perm => userPermissions.includes(perm));
+
+    if (!hasPermission) {
+      return res.status(403).json({
+        error: `Forbidden: Missing required permissions: ${permissions.join(', ')}`,
+        code: 'INSUFFICIENT_PERMISSIONS'
+      });
+    }
+
+    next();
+  };
+}
+
+/**
+ * Middleware to check if user is admin
+ *
+ * @returns {Function} Express middleware function
+ */
+export function requireAdmin(req, res, next) {
+  if (!req.user || !req.user.isAdmin) {
+    return res.status(403).json({
+      error: 'Forbidden: Admin access required',
+      code: 'ADMIN_REQUIRED'
+    });
+  }
+  next();
+}
+
+/**
+ * Error handler for authentication errors
+ *
+ * @param {Error} err - Error object
+ * @param {Object} req - Express request
+ * @param {Object} res - Express response
+ * @param {Function} next - Express next function
+ */
+export function authErrorHandler(err, req, res, next) {
+  if (err.code === 'INVALID_TOKEN' || err.code === 'TOKEN_EXPIRED') {
+    return res.status(401).json({
+      error: err.message,
+      code: err.code
+    });
+  }
+  next(err);
+}