SSL Certificate Monitor

Web application to monitor SSL certificate expiry dates. Features include:

• Admin Panel: Manage URLs with optional customer information
• SSL Monitoring: Track certificate expiry dates, issuer,type, and days remaining
• Caching: Intelligent caching with configurable refresh rates
• Sorting: Sort by days remaining, expiry date, customer name, or FQDN
• Enhanced Details: View full certificate details including issuer, subject, SANs
• URL Validation: Validate URLs before adding with reachability checks
• Custom Ports: Support for非-standard SSL ports (e.g., :8443)

Features

1. URL Management (Admin Panel)

• Add new domains with optional customer information
• Edit existing entries
• Delete entries
• View a 11 overview of all monitored certificates

2. SSL Certificate Monitoring

• Display expiry date and days remaining
• Show certificate issuer (Let's Encrypt, Sectigo, DigiCert, etc.)
• Status indicators:
  • Active: > 90 days remaining
  • Warning: 30-90 days remaining
  • Expiring Soon: < 30 days remaining
  • Expired: < 0 days (negative days shown)

3. Enhanced Certificate Details

View comprehensive certificate information:

• Full issuer details (O, CN, etc.)
• Subject information
• Validity period (notBefore, notAfter)
• Serial number and version
• Algorithm details (key algorithm, signature algorithm)
• SAN (Subject Alternative Names)
• SHA256 fingerprint

4. URL Validation

• Validates HTTPS protocol
• Checks domain format
• Tests server reachability before adding
• Provides helpful error messages

5. Custom Port Support

• Automatically detects port from URL (default: 443)
• Supports custom ports (e.g., https://example.com:8443)

Technical Details

Database

• SQLite-based storage
• Two main tables: urls and ssl_cache
• Intelligent caching with configurable refresh rates

Caching Strategy

• Less than 30 days: Refresh every 12 hours
• 30-90 days: Daily refresh
• More than 90 days: Weekly refresh

API Endpoints

GET /api/urls

Get all monitored URLs (supports sorting):

• sort_by: days_remaining (default), fqdn, customer_name, expiry_date
• sort_order: asc (default), desc

POST /api/urls

Add new URL:

{
  "fqdn": "https://example.com",
  "customer_number": "12345",
  "customer_name": "Example Customer"
}

GET /api/certs/<fqdn>/details

Get full certificate details for a domain

POST /api/certs/<fqdn>/refresh

Force refresh certificate data

Installation

From Source

# Clone repository
git clone <your-repo-url>
cd ssl-checker

# Create virtual environment
python3 -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

# Install dependencies
pip install -r requirements.txt

# Run application
python run.py

Using Docker

coming soon...

Configuration

No external configuration needed. All settings are in the code.

Testing

Using curl

# Test API
curl http://localhost:4444/api/urls

# Add URL
curl -X POST http://localhost:4444/api/urls \
  -H "Content-Type: application/json" \
  -d '{"fqdn":"https://example.com"}'

# Get certificate details
curl http://localhost:4444/api/certs/example.com/details

Manual Testing Checklist

• Add new URL with valid domain
• Verify URL validation rejects invalid URLs
• Check certificate data is correctly stored
• Verify sorting works correctly
• Test custom port support
• Check enhanced certificate details endpoint

Development

Project Structure

ssl-checker/
├── app/
│   ├── __init__.py
│   ├── routes.py        # Flask routes and API endpoints
│   ├── database.py      # Database connection and queries
│   ├── ssl_checker.py   # SSL certificate utilities
│   ├── ssl_extended.py  # Enhanced certificate utilities
│   ├── url_utils.py     # URL validation utilities
│   └── templates/       # HTML templates
├── run.py               # Application entry point
└── README.md            # This file

Adding New Features

1. Add validation logic in url_utils.py
2. Add certificate utilities in ssl_checker.py or ssl_extended.py
3. Add API endpoints in routes.py
4. Update templates in templates/
5. Tests before committing

License

MIT License

Support

For issues or questions, please open an issue on GitHub.