ssl-tool

A CLI tool to inspect and retrieve SSL/TLS certificates.

Installation

go install github.com/swisscom/ssl-tool@latest

Usage

ssl-tool [command] [-l log-level]

Commands:
  cert    Certificate operations
  client  Client operations

Flags:
  -l, --log-level string   log level (debug, info, warning, error) (default "warning")
  -v, --version            version for ssl-tool
  -h, --help               help for ssl-tool

ssl-tool client get-certificate <url>

Fetch and display the certificate chain from a live HTTPS endpoint.

ssl-tool client get-certificate https://expired.badssl.com

• Displays the leaf certificate details (subject, issuer, DNS names, validity, key info)
• Displays the full certificate chain with subject, issuer, and color-coded expiry
• Shows a warning banner for invalid/untrusted certificates
• Expiry dates are color-coded: green (valid), yellow (< 30 days), red (expired)

ssl-tool cert parse <certfile>

Parse and display a local PEM certificate file (single cert or chain).

ssl-tool cert parse cert.pem