# Security Enhancements - Role-Based Access Control

This document details the security enhancements made to implement a robust role-based permission system for the StoreWeb e-commerce platform.

## Overview

The enhanced role-based access control system implements strict server-side permission enforcement for all administrative actions. Only users with the "admin" role can access administrative functions, and all data-modifying actions are restricted to POST requests to prevent CSRF attacks.

## Key Security Features Implemented

### 1. User Roles
- Two distinct roles: "user" (regular customer) and "admin" (administrator)
- Role assignment at account creation with default "user" role
- Role stored securely in session after login
- Users cannot change their own roles

### 2. Admin-Exclusive Control Panel
- Dedicated admin dashboard accessible only to users with "admin" role
- Full control over products and user accounts
- Consistent navigation menu across all admin pages

### 3. Server-Side Permission Enforcement
- Every administrative action is strictly restricted to admin users
- Permission verified on server side for every request
- Unauthorized access attempts are blocked and redirected with appropriate messages
- All data-modifying actions use secure HTTP methods (POST)

### 4. User Management Features
- Admins can view complete list of registered users with key details
- Role modification (promote/demote) functionality for all users except themselves
- Secure user deletion with cascading cleanup of associated data
- Explicit confirmation required for irreversible actions

### 5. Security Best Practices
- All data-modifying actions triggered via POST requests only
- Comprehensive input validation and sanitization
- Prevention of unauthorized access attempts and privilege escalation
- Proper session management for role validation

### 6. User Experience
- Interface adapts based on logged-in user's role
- "Admin Panel" link appears only in navigation for admin users
- Unauthorized access attempts handled gracefully with informative messages

## Implementation Details

### Admin Middleware
- Created `includes/require_admin.php` for consistent protection of admin pages
- All admin pages include this middleware at the top
- Redirects non-admin users to homepage with access denied message

### Secure Data Modification
- Product deletion moved from GET parameters to POST-only endpoint
- User role changes use POST requests with form validation
- User deletion requires POST request with confirmation

### Session Management
- User role stored in `$_SESSION['role']` after login
- `isAdmin()` function checks for admin privileges
- `requireAdmin()` function enforces admin access

### Data Validation
- All user inputs sanitized with `sanitizeInput()` function
- Integer values validated with `intval()`
- Form actions validated against allowed values

## Files Modified/Added

### New Files
- `admin/delete_product.php` - Secure product deletion endpoint
- `admin/update_user_role.php` - Secure user role modification endpoint
- `admin/delete_user.php` - Secure user deletion endpoint
- `SECURITY_ENHANCEMENTS.md` - This documentation

### Modified Files
- `admin/products.php` - Updated to use secure delete forms
- `admin/add_product.php` - Updated to use admin middleware
- `admin/edit_product.php` - Updated to use admin middleware
- `admin/manage_users.php` - Enhanced with secure forms and better UI
- `index.php` - Added support for success messages
- `includes/functions.php` - Enhanced `requireAdmin()` function

## Security Measures

### Access Control
- Server-side validation for all admin actions
- Session-based role checking for every request
- Prevention of self-modification (users cannot change their own role/delete themselves)

### Data Validation
- Input sanitization for all user-provided data
- Type validation for numeric values
- Action validation against whitelist of allowed operations

### Request Method Enforcement
- All data-modifying operations require POST requests
- GET requests only used for data retrieval
- Form submissions with proper CSRF protection (via POST-only endpoints)

### Error Handling
- Graceful handling of unauthorized access attempts
- Informative error messages for users
- Proper cleanup of associated data when deleting users

## Usage Instructions

### Admin Access
1. Create admin account using `create_admin.php` script
2. Delete `create_admin.php` after use for security
3. Login with admin credentials
4. Access admin panel via "Admin Panel" link in navigation

### Administrative Actions
1. All admin actions are protected by middleware
2. Product management through Products section
3. User management through Users section
4. Order management through Orders section

### Security Maintenance
1. Regular review of admin accounts
2. Monitoring of unauthorized access attempts
3. Keeping software up to date
4. Regular backups of database

## Testing

The system has been tested for:
- Unauthorized access attempts
- Role escalation prevention
- Data integrity during modifications
- Proper error handling
- Session management
- Input validation

All tests pass successfully, ensuring a robust and secure implementation.