# Security Documentation

## Authentication System

### Authentication Stack
```python
# Settings configuration
AUTHENTICATION_BACKENDS = [
    'django.contrib.auth.backends.ModelBackend',
    'allauth.account.auth_backends.AuthenticationBackend',
]

INSTALLED_APPS = [
    'django.contrib.auth',
    'django.contrib.sessions',
    'allauth',
    'allauth.account',
    'allauth.socialaccount',
    'oauth2_provider',
]
```

### Authentication Flow
```mermaid
sequenceDiagram
    User->>+Server: Login Request
    Server->>+Auth Service: Validate Credentials
    Auth Service->>+Database: Check User
    Database-->>-Auth Service: User Data
    Auth Service-->>-Server: Auth Token
    Server-->>-User: Session Cookie
```

## Authorization Framework

### Permission System

#### Model Permissions
```python
class Park(models.Model):
    class Meta:
        permissions = [
            ("can_publish_park", "Can publish park"),
            ("can_moderate_park", "Can moderate park"),
            ("can_verify_park", "Can verify park information"),
        ]
```

#### View Permissions
```python
class ModeratedCreateView(LoginRequiredMixin, PermissionRequiredMixin):
    permission_required = 'parks.can_publish_park'
    raise_exception = True
```

### Role-Based Access Control

#### User Groups
1. Administrators
   - Full system access
   - Configuration management
   - User management

2. Moderators
   - Content moderation
   - User management
   - Report handling

3. Company Representatives
   - Company profile management
   - Official updates
   - Response management

4. Regular Users
   - Content creation
   - Review submission
   - Media uploads

#### Permission Matrix
```python
ROLE_PERMISSIONS = {
    'administrator': [
        'can_manage_users',
        'can_configure_system',
        'can_moderate_content',
    ],
    'moderator': [
        'can_moderate_content',
        'can_manage_reports',
        'can_verify_information',
    ],
    'company_rep': [
        'can_manage_company',
        'can_post_updates',
        'can_respond_reviews',
    ],
    'user': [
        'can_create_content',
        'can_submit_reviews',
        'can_upload_media',
    ],
}
```

## Security Controls

### Request Security

#### CSRF Protection
```python
MIDDLEWARE = [
    'django.middleware.csrf.CsrfViewMiddleware',
]

# Template configuration
{% csrf_token %}

# AJAX request handling
headers: {
    'X-CSRFToken': getCookie('csrftoken')
}
```

#### XSS Prevention
```python
# Template autoescape
{% autoescape on %}
    {{ user_content }}
{% endautoescape %}

# Content Security Policy
CSP_DEFAULT_SRC = ("'self'",)
CSP_SCRIPT_SRC = ("'self'",)
CSP_STYLE_SRC = ("'self'", "'unsafe-inline'")
CSP_IMG_SRC = ("'self'", "data:", "https:")
```

### Data Protection

#### Password Security
```python
# Password validation
AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
        'OPTIONS': {
            'min_length': 12,
        }
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]
```

#### Data Encryption
```python
# Database encryption
ENCRYPTED_FIELDS = {
    'fields': {
        'users.User.ssn': 'django_cryptography.fields.encrypt',
        'payment.Card.number': 'django_cryptography.fields.encrypt',
    },
}

# File encryption
ENCRYPTED_FILE_STORAGE = 'django_cryptography.storage.EncryptedFileSystemStorage'
```

### Session Security

#### Session Configuration
```python
# Session settings
SESSION_COOKIE_SECURE = True
SESSION_COOKIE_HTTPONLY = True
SESSION_COOKIE_SAMESITE = 'Lax'
SESSION_ENGINE = 'django.contrib.sessions.backends.cached_db'
SESSION_EXPIRE_AT_BROWSER_CLOSE = True
```

#### Session Management
```python
# Session cleanup
CELERYBEAT_SCHEDULE = {
    'cleanup-expired-sessions': {
        'task': 'core.tasks.cleanup_expired_sessions',
        'schedule': crontab(hour=4, minute=0)
    },
}
```

## API Security

### Authentication
```python
REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': [
        'rest_framework_jwt.authentication.JSONWebTokenAuthentication',
        'rest_framework.authentication.SessionAuthentication',
    ],
    'DEFAULT_PERMISSION_CLASSES': [
        'rest_framework.permissions.IsAuthenticated',
    ],
}
```

### Rate Limiting
```python
# Rate limiting configuration
REST_FRAMEWORK = {
    'DEFAULT_THROTTLE_CLASSES': [
        'rest_framework.throttling.AnonRateThrottle',
        'rest_framework.throttling.UserRateThrottle'
    ],
    'DEFAULT_THROTTLE_RATES': {
        'anon': '100/day',
        'user': '1000/day'
    }
}
```

## Security Headers

### HTTP Security Headers
```python
MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
]

SECURE_HSTS_SECONDS = 31536000
SECURE_HSTS_INCLUDE_SUBDOMAINS = True
SECURE_HSTS_PRELOAD = True
SECURE_SSL_REDIRECT = True
SECURE_REFERRER_POLICY = 'same-origin'
SECURE_BROWSER_XSS_FILTER = True
```

## File Upload Security

### Upload Configuration
```python
# File upload settings
FILE_UPLOAD_MAX_MEMORY_SIZE = 2621440  # 2.5 MB
FILE_UPLOAD_PERMISSIONS = 0o644
ALLOWED_EXTENSIONS = ['jpg', 'jpeg', 'png', 'gif']

def validate_file_extension(value):
    ext = os.path.splitext(value.name)[1]
    if not ext.lower() in ALLOWED_EXTENSIONS:
        raise ValidationError('Unsupported file extension.')
```

### Media Security
```python
# Serve media files securely
@login_required
def serve_protected_file(request, path):
    if not request.user.has_perm('can_access_file'):
        raise PermissionDenied
    response = serve(request, path, document_root=settings.MEDIA_ROOT)
    response['Content-Disposition'] = 'attachment'
    return response
```

## Security Monitoring

### Audit Logging
```python
# Audit log configuration
AUDIT_LOG_HANDLERS = {
    'security': {
        'level': 'INFO',
        'class': 'logging.handlers.RotatingFileHandler',
        'filename': 'logs/security.log',
        'maxBytes': 1024*1024*5,  # 5 MB
        'backupCount': 5,
    },
}

# Audit log usage
def log_security_event(event_type, user, details):
    logger.info(f'Security event: {event_type}', extra={
        'user_id': user.id,
        'ip_address': get_client_ip(request),
        'details': details
    })
```

### Security Alerts
```python
# Alert configuration
SECURITY_ALERTS = {
    'login_attempts': {
        'threshold': 5,
        'window': 300,  # 5 minutes
        'action': 'account_lock'
    },
    'api_errors': {
        'threshold': 100,
        'window': 3600,  # 1 hour
        'action': 'notify_admin'
    }
}
```

## Incident Response

### Security Incident Workflow
1. Detection
2. Analysis
3. Containment
4. Eradication
5. Recovery
6. Lessons Learned

### Response Actions
```python
class SecurityIncident:
    def contain_threat(self):
        # Lock affected accounts
        # Block suspicious IPs
        # Disable compromised tokens
        
    def investigate(self):
        # Collect logs
        # Analyze patterns
        # Document findings
        
    def recover(self):
        # Restore systems
        # Reset credentials
        # Update security controls