ssl-certificate-monitor

# SSL Certificate Monitor

## What This Does

A CLI tool to monitor SSL/TLS certificates for expiration dates, security issues, and basic compliance checks. Check single domains or multiple domains from a list, get detailed certificate information, and receive alerts before certificates expire.

Key features:
- **Check expiration dates** for SSL certificates on domains and subdomains
- **Detailed certificate info** - issuer, subject, serial number, signature algorithm
- **Security validation** - check certificate chain, basic trust validation
- **Batch monitoring** - check multiple domains from a file or list
- **Alert thresholds** - warn when certificates expire within specified days (default 30 days)
- **JSON output** - machine-readable output for integration with monitoring systems
- **Simple CLI interface** - easy to use in scripts or cron jobs
- **No external API required** - uses Python's SSL/TLS libraries

## When To Use

- You need to monitor SSL certificate expiration for your websites
- You want to automate certificate renewal reminders
- You're managing multiple domains and subdomains
- You need to validate certificate chain and basic security
- You want to integrate SSL monitoring into your DevOps pipeline
- You're auditing domains for certificate compliance
- You need to check certificates on internal servers or development environments

## Usage

Basic commands:

```bash
# Check a single domain
python3 scripts/main.py check example.com

# Check with custom port
python3 scripts/main.py check example.com --port 443

# Check multiple domains from a file (one domain per line)
python3 scripts/main.py batch domains.txt

# Set custom warning threshold (days before expiration)
python3 scripts/main.py check example.com --warning-days 14

# Output JSON for machine processing
python3 scripts/main.py check example.com --json

# Check certificate details (issuer, subject, algorithm, etc.)
python3 scripts/main.py details example.com

# Validate certificate chain and...

# SSL Certificate Monitor

Monitor SSL/TLS certificates for expiration dates, security issues, and compliance across domains and subdomains.

## Features

- Check expiration dates for SSL certificates
- Detailed certificate information (issuer, subject, algorithm)
- Batch monitoring of multiple domains
- Alert thresholds for expiring certificates
- JSON output for machine processing
- Basic certificate chain validation

## Quick Start

```bash
# Check a single domain
python3 scripts/main.py check example.com

# Check multiple domains from a file
python3 scripts/main.py batch domains.txt --warning-days 30

# Get certificate details
python3 scripts/main.py details example.com
```

## Installation

This skill requires Python 3.x and the `cryptography` library:

```bash
pip3 install cryptography
```

## Usage Examples

### Check domain with custom warning threshold
```bash
python3 scripts/main.py check example.com --warning-days 14
```

### Output JSON for automation
```bash
python3 scripts/main.py check example.com --json
```

### Validate certificate chain
```bash
python3 scripts/main.py validate example.com
```

## File Format for Batch Checking

Create a text file with one domain per line:

```
example.com
api.example.com
staging.example.com
blog.example.com:8443
```

## Output

The tool provides color-coded output:
- ✅ Valid certificates
- ⚠️  Certificates expiring soon (within warning threshold)
- ❌ Expired or invalid certificates

## Limitations

- Network connectivity required
- Standard TLS handshake only
- No deep security audits
- No built-in notification system

## License

This skill is part of the OpenClaw Skill Factory portfolio.