Security and Privacy Measures [40-6]

[mehalyna]

Description: Implement essential security measures to protect the messaging data between investors and startups, ensuring the system adheres to best practices in data protection and user privacy.

Technical Steps:

1. Input Sanitization and Validation

Ensure all inputs are properly sanitized to prevent common web security flaws such as SQL injection and cross-site scripting (XSS).

Action Steps:

• Use Django forms or serializers to validate and clean incoming data before it hits your database or business logic.
• For Django REST Framework, ensure that all fields in serializers are correctly configured to reject harmful inputs. E.g.

  
  from rest_framework import serializers

class MessageSerializer(serializers.ModelSerializer): class Meta: model = Message fields = 'all' extra_kwargs = { 'text': {'validators': [custom_validator_that_escapes_xss]}, }

#### 2. **Implementing HTTPS**
Use HTTPS to encrypt data transmitted between the client and server to prevent interception by unauthorized parties.

**Action Steps:**
- Ensure your deployment is configured to use HTTPS by default.
- Configure Django to redirect all incoming HTTP requests to HTTPS using the `SecurityMiddleware`.

```python
# settings.py
SECURE_SSL_REDIRECT = True
SESSION_COOKIE_SECURE = True
CSRF_COOKIE_SECURE = True

3. Data Encryption

Encrypt sensitive data stored in the database, particularly messages that may contain confidential information.

Action Steps:

• Use a library like django-cryptography to encrypt fields in your models that store sensitive data such as messages. E.g.

  
  from django_cryptography.fields import encrypt

class Message(models.Model): text = encrypt(models.TextField()) ...

#### 4. **Access Control**
Ensure that users can only access messages that they are authorized to view.

**Action Steps:**
- Implement object-level permissions or use Django's built-in permissions framework to control access to messages based on the user's role and ownership.
- Use Django Guardian for more granular permissions if necessary.

```python
from rest_framework.permissions import BasePermission

class IsOwnerOrRecipient(BasePermission):
    def has_object_permission(self, request, view, obj):
        return obj.sender == request.user or obj.receiver == request.user

5. Regular Security Audits and Updates

Regularly audit the security of your application and update dependencies to mitigate vulnerabilities.

Action Steps:

• Use tools like bandit for static analysis of security vulnerabilities in your Python code.
• Keep your Python dependencies up-to-date, especially Django and DRF, to include security patches.

6. Rate Limiting

Prevent abuse and DoS attacks by limiting the rate at which users can send messages.

Action Steps:

• Use Django’s cache framework or a third-party package like django-ratelimit to limit the number of messages a user can send per minute.

from ratelimit.decorators import ratelimit

@ratelimit(key='user', rate='5/m', block=True)
def send_message(request):
    # Your send message logic

7. Logging and Monitoring

Implement logging and monitoring to detect unusual activities that might indicate a security breach or misuse of the messaging system.

Action Steps:

• Use Django’s logging framework to log access and actions taken by users.
• Set up monitoring with tools like Sentry to capture exceptions and errors in real-time.

import logging

logger = logging.getLogger(__name__)

def send_message(request):
    logger.info(f'Message sent by {request.user.username}')
    # Your logic here

Task #40