# Authentication and Authorization Implementation Summary

## Overview
This document summarizes the complete implementation of authentication and authorization for the Meldestelle application. The system provides comprehensive user authentication, JWT-based session management, and role-based access control.

## ✅ Implemented Components

### 1. Authentication Services
- **AuthenticationService**: Complete user authentication with login, registration, password management
- **JwtService**: JWT token creation and validation using HMAC512 algorithm
- **PasswordService**: Secure password hashing and validation
- **UserAuthorizationService**: Role and permission management

### 2. Database Layer
- **UserTable**: Complete user entity with authentication fields
- **UserRepository**: CRUD operations for user management
- **Role and Permission Tables**: Support for role-based access control
- **Database Integration**: Proper repository implementations

### 3. API Endpoints
- **POST /auth/login**: User authentication with JWT token generation
- **POST /auth/register**: User registration with validation
- **GET /auth/profile**: Protected endpoint for user profile (requires JWT)
- **POST /auth/change-password**: Password change functionality (requires JWT)
- **POST /auth/refresh**: JWT token refresh (requires valid token)
- **POST /auth/logout**: User logout (client-side token invalidation)

### 4. Security Configuration
- **JWT Authentication Middleware**: Configured with HMAC512 algorithm
- **CORS Configuration**: Proper cross-origin resource sharing setup
- **Token Validation**: Comprehensive JWT token validation
- **Security Headers**: Proper HTTP security headers

### 5. Authorization System
- **AuthorizationHelper**: Comprehensive helper for permission and role checks
- **Role-Based Access Control**: Support for checking user roles and permissions
- **Extension Functions**: Easy-to-use authorization functions for controllers
- **Error Handling**: Proper 401/403 HTTP status responses

## 🔧 Key Features

### Authentication Features
- ✅ User login with username/email and password
- ✅ Secure password hashing with salt
- ✅ Account locking after failed login attempts
- ✅ JWT token generation and validation
- ✅ Token refresh functionality
- ✅ Password change with current password verification
- ✅ User registration with validation
- ✅ Email verification support (database ready)

### Authorization Features
- ✅ Role-based access control
- ✅ Permission-based access control
- ✅ JWT token extraction and validation
- ✅ User context in protected endpoints
- ✅ Flexible authorization checks (any role/permission)
- ✅ Proper error responses for unauthorized access

### Security Features
- ✅ HMAC512 JWT signing algorithm
- ✅ Configurable JWT expiration
- ✅ Environment-based configuration
- ✅ Account locking mechanism
- ✅ Failed login attempt tracking
- ✅ Secure password requirements

## 📁 File Structure

### Core Services
```
member-management/src/
├── commonMain/kotlin/at/mocode/members/domain/
│   ├── model/
│   │   ├── DomUser.kt                    # User domain model
│   │   └── DomRolle.kt                   # Role domain model
│   ├── service/
│   │   ├── JwtService.kt                 # JWT service interface
│   │   ├── UserAuthorizationService.kt   # Authorization service
│   │   └── PasswordService.kt            # Password service
│   └── repository/
│       └── UserRepository.kt             # User repository interface
└── jvmMain/kotlin/at/mocode/members/
    ├── domain/service/
    │   ├── AuthenticationService.kt      # Authentication implementation
    │   └── JwtService.kt                 # JWT implementation (JVM)
    ├── infrastructure/
    │   ├── table/
    │   │   └── UserTable.kt              # Database table definition
    │   └── repository/
    │       └── UserRepositoryImpl.kt     # Repository implementation
```

### API Gateway
```
api-gateway/src/main/kotlin/at/mocode/gateway/
├── auth/
│   └── AuthorizationHelper.kt            # Authorization utilities
├── config/
│   └── SecurityConfig.kt                 # Security configuration
└── routing/
    ├── RoutingConfig.kt                  # Main routing setup
    └── AuthRoutes.kt                     # Authentication endpoints
```

## 🧪 Testing

### Test Script
- **test_authentication_authorization.kt**: Comprehensive test script covering:
  - Health check
  - User registration
  - User login
  - Protected endpoint access
  - Token refresh
  - Password change
  - Logout

### Manual Testing
To test the implementation:

1. **Start the application**
2. **Run the test script**: `kotlin test_authentication_authorization.kt`
3. **Manual API testing** using tools like Postman or curl

### Example API Calls

#### Login
```bash
curl -X POST http://localhost:8080/auth/login \
  -H "Content-Type: application/json" \
  -d '{"usernameOrEmail": "admin", "password": "admin123"}'
```

#### Access Protected Profile
```bash
curl -X GET http://localhost:8080/auth/profile \
  -H "Authorization: Bearer YOUR_JWT_TOKEN"
```

#### Register User
```bash
curl -X POST http://localhost:8080/auth/register \
  -H "Content-Type: application/json" \
  -d '{
    "personId": "550e8400-e29b-41d4-a716-446655440000",
    "username": "newuser",
    "email": "user@example.com",
    "password": "SecurePassword123!"
  }'
```

## 🔒 Security Considerations

### Implemented Security Measures
- ✅ Password hashing with salt
- ✅ JWT token expiration
- ✅ Account locking after failed attempts
- ✅ Secure HTTP headers
- ✅ Input validation
- ✅ SQL injection prevention (using Exposed ORM)
- ✅ CORS configuration

### Production Recommendations
- 🔧 Use environment variables for JWT secrets
- 🔧 Implement rate limiting
- 🔧 Add request logging
- 🔧 Use HTTPS in production
- 🔧 Implement token blacklisting for logout
- 🔧 Add email verification workflow
- 🔧 Implement password reset functionality

## 📊 Database Schema

### User Table (benutzer)
```sql
CREATE TABLE benutzer (
    id UUID PRIMARY KEY,
    person_id UUID NOT NULL,
    username VARCHAR(50) UNIQUE NOT NULL,
    email VARCHAR(100) UNIQUE NOT NULL,
    password_hash VARCHAR(255) NOT NULL,
    salt VARCHAR(64) NOT NULL,
    is_active BOOLEAN DEFAULT true,
    is_email_verified BOOLEAN DEFAULT false,
    failed_login_attempts INTEGER DEFAULT 0,
    locked_until TIMESTAMP NULL,
    last_login_at TIMESTAMP NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
```

## 🚀 Usage Examples

### In Controllers
```kotlin
// Check if user has specific permission
if (!call.requirePermission(authHelper, BerechtigungE.USER_MANAGEMENT)) {
    return@post
}

// Check if user has specific role
if (!call.requireRole(authHelper, RolleE.ADMIN)) {
    return@get
}

// Get current user ID
val userId = authHelper.getCurrentUserId(call)
```

### JWT Token Structure
```json
{
  "iss": "meldestelle-api",
  "aud": "meldestelle-users",
  "sub": "user-uuid",
  "username": "username",
  "personId": "person-uuid",
  "permissions": ["PERMISSION1", "PERMISSION2"],
  "iat": 1234567890,
  "exp": 1234571490
}
```

## ✅ Completion Status

The authentication and authorization system is **FULLY IMPLEMENTED** and includes:

- ✅ Complete user authentication flow
- ✅ JWT-based session management
- ✅ Role-based access control
- ✅ Comprehensive API endpoints
- ✅ Security middleware configuration
- ✅ Database integration
- ✅ Test coverage
- ✅ Documentation

The system is ready for production use with proper environment configuration and additional security hardening as recommended above.
