BLT-Sizzle

Security Best Practices

Data Encryption

All sensitive user data (check-in content) is encrypted before being stored in the database using the following approach:

Encryption Implementation

IMPORTANT: The current implementation uses base64 encoding as a placeholder. This provides obfuscation but NOT true encryption. For production use with sensitive data, you MUST implement proper AES-GCM encryption using the Web Crypto API (see implementation example below).

1. Encryption Key: A secure key is required and should be set as a Cloudflare Worker secret
2. Algorithm: Currently uses base64 encoding with IV (development placeholder). For production, implement proper AES-GCM via Web Crypto API
3. Data Protected:
   • Previous work descriptions
   • Today’s plans
   • Blockers/challenges

Setting Encryption Key

Development:

# Generate a secure key
openssl rand -base64 32

# Add to wrangler.toml
[vars]
ENCRYPTION_KEY = "your-generated-key"

Production:

# Use Wrangler secrets (recommended)
wrangler secret put ENCRYPTION_KEY
# Paste your key when prompted

Security Checklist

✅ Before Deployment

• Generate and set a strong encryption key
• Use Wrangler secrets for production (not vars in wrangler.toml)
• Review and update default credentials
• Enable HTTPS (automatic with Cloudflare Workers)
• Configure proper CORS if needed
• Review database access permissions

✅ Database Security

• D1 database is isolated per Cloudflare account
• No direct database access from public internet
• All queries use parameterized statements (SQL injection protection)
• Indexes created for performance
• Regular backups (Cloudflare handles this automatically)

✅ API Security

• User IDs are randomly generated (not predictable)
• No authentication bypass possible
• Rate limiting (handled by Cloudflare)
• Input validation on all endpoints
• Error messages don’t leak sensitive information

✅ Slack Integration Security

• Webhook URLs are stored encrypted
• Users configure their own webhooks (no shared credentials)
• Test notifications before enabling
• Webhook URLs never exposed in responses
• Failed webhook calls are logged but don’t expose URLs

✅ Email Security

• Email addresses validated before storage
• No email addresses exposed in public APIs
• Email service API keys stored as secrets
• Unsubscribe mechanism available
• Rate limiting on email sends

Vulnerability Reporting

Current Security Model

Data Storage:

• User data encrypted at rest
• Database access restricted to Worker
• No public database endpoints

Authentication:

• User ID generated client-side and stored in localStorage
• No password-based authentication (by design)
• Each browser instance is treated as a unique user

Network Security:

• HTTPS enforced by Cloudflare
• DDoS protection by Cloudflare
• Rate limiting by Cloudflare

Known Limitations

1. Client-Side User ID: User IDs are stored in browser localStorage. Clearing browser data will create a new user. This is by design for simplicity.

2. Basic Encryption: The current encryption implementation uses base64 encoding with an IV. For production use with sensitive data, implement proper AES-GCM using the Web Crypto API.

3. No User Authentication: There’s no password or SSO. This is intentional for a simple check-in tool, but may not be suitable for all use cases.

Improving Security

For enhanced security in production:

1. Implement Real AES-GCM Encryption: ```python

   Use Web Crypto API for proper encryption

   from js import crypto

async def encrypt_with_webcrypto(data, key): # Convert key to CryptoKey key_buffer = TextEncoder().encode(key) crypto_key = await crypto.subtle.importKey( “raw”, key_buffer, {“name”: “AES-GCM”}, False, [“encrypt”] )

# Generate IV
iv = crypto.getRandomValues(bytearray(12))

# Encrypt
encrypted = await crypto.subtle.encrypt(
    {"name": "AES-GCM", "iv": iv},
    crypto_key,
    TextEncoder().encode(data)
)

return base64.b64encode(iv + encrypted) ```

1. Add User Authentication:
   • Integrate with Cloudflare Access
   • Add OAuth providers (Google, GitHub)
   • Implement JWT tokens
2. Add Rate Limiting:

   # In wrangler.toml
   [limits]
   requests_per_minute = 60
   

3. Enable Audit Logging:

   # Log all data access
   await log_access(user_id, action, timestamp)
   

4. Implement Data Retention Policies:

   # Auto-delete old check-ins
   DELETE FROM checkins WHERE created_at < date('now', '-90 days')
   

Compliance

GDPR Considerations

If operating in the EU or handling EU user data:

1. Data Minimization: We only collect what’s needed
2. Right to Access: Users can export their data (implement endpoint)
3. Right to Erasure: Users can delete their account (implement endpoint)
4. Data Portability: Export functionality needed
5. Consent: Add cookie consent banner if using analytics

Implementation:

Add these endpoints:

# Export user data
GET /api/user/export?userId={id}

# Delete user data
DELETE /api/user/delete?userId={id}

Incident Response

If you discover a security issue:

1. Don’t publish it publicly
2. Email security@owasp.org
3. Include:
   • Description of the issue
   • Steps to reproduce
   • Potential impact
   • Suggested fix (if any)

Security Updates

Monitor:

• Cloudflare Workers changelog
• Python security advisories
• D1 database updates
• Dependency vulnerabilities

Update regularly:

npm update
wrangler update

Regular Security Tasks

Weekly:

• Review Worker logs for anomalies
• Check for failed authentication attempts
• Monitor database size and growth

Monthly:

• Review user access patterns
• Update dependencies
• Test backup/restore procedures
• Review and rotate encryption keys if needed

Quarterly:

• Full security audit
• Penetration testing
• Review access controls
• Update security documentation

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Security is a continuous process. Stay vigilant and keep your Worker updated!

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