SSL Certificate Checker

Check SSL/TLS certificate details including expiration date, issuer, validity, cipher suites, and security warnings for any domain. Use when verifying HTTPS...

Security Scan

The skill is an instruction-only guide that correctly describes using openssl to inspect TLS certificates; the only mismatch is it doesn't declare that openssl is required.

Purpose & Capability

The SKILL.md describes certificate inspection and gives concrete openssl commands that match the stated purpose. However, the skill metadata declares no required binaries even though the instructions explicitly require the openssl binary (inconsistent declaration).

Instruction Scope

Instructions are narrowly scoped to reading certificate data via openssl and piping output; they do perform network connections to the target domain (expected for this task) and reference /dev/null only as part of the command pipeline.

Install Mechanism

No install spec and no code files — lowest-risk instruction-only skill. Nothing is downloaded or written to disk by the skill itself.

Credentials

The skill requests no environment variables, secrets, or config paths. That is proportionate for a read-only certificate checker.

Persistence & Privilege

always is false and model invocation is allowed (platform default). The skill does not request persistent privileges or modify other skills/configs.

Assessment

This skill is basically documentation with example openssl commands — it's coherent with its purpose. Before installing/using it, ensure the agent environment has a trustworthy openssl binary available (the SKILL.md assumes openssl but the metadata doesn't list it). Be aware the commands will open outbound TLS connections to whatever domain you supply, so avoid running the checks against sensitive internal hosts unless you trust the environment and network. If you need the agent to run these commands autonomously, confirm you trust the agent's ability to execute shell commands and that it will not be given internal targets or credentials inadvertently.

Analyze SSL/TLS certificates for any domain to verify security configuration and monitor expiration.

When to Use

• Checking SSL certificate expiration dates
• Verifying certificate chain and issuer
• Troubleshooting HTTPS connection issues
• Auditing website security configuration
• Monitoring certificates before renewal

When NOT to Use

• Penetration testing (this is read-only)
• Internal network certificates (use dedicated tools)
• Certificate installation (this only checks, doesn't install)

Examples

Basic Certificate Check

# Check certificate for a domain
openssl s_client -connect example.com:443 -servername example.com </dev/null 2>/dev/null | openssl x509 -noout -dates -subject -issuer

# Get detailed certificate information
echo | openssl s_client -connect example.com:443 -servername example.com 2>/dev/null | openssl x509 -noout -text