SSL Certificate Monitor

Check SSL/TLS certificate expiry, issuer, protocol, and SANs for one or more domains. Use when asked to check SSL certificates, monitor cert expiry, verify HTTPS is working, audit domain security, or check if a certificate is about to expire. Supports custom ports and warning thresholds. No external dependencies — uses Python stdlib ssl module.

Check SSL certificate health for any domain — expiry, issuer, protocol version, and Subject Alternative Names.

Quick Start

python3 scripts/check_ssl.py example.com
python3 scripts/check_ssl.py example.com google.com github.com --warn-days 30
python3 scripts/check_ssl.py internal.host --port 8443 --json

Features

• Expiry check — days remaining with configurable warning threshold
• Multi-domain — check multiple domains in one command
• Certificate details — subject, issuer, protocol, serial number, SANs
• Error handling — detects DNS failures, timeouts, verification errors, refused connections
• Exit codes — 0 = all ok, 1 = warnings, 2 = expired or failed (useful for cron/CI)
• No dependencies — Python stdlib only

Options

Flag	Description
--warn-days N	Warning threshold in days (default: 14)
--port PORT	Port to check (default: 443)
--json	Output structured JSON
--timeout N	Connection timeout in seconds (default: 10)

Use Cases

• Daily cron job to monitor production domains
• Pre-deployment cert validation
• Audit all company domains in one pass
• CI/CD pipeline gate for cert health