cert

README

cert — a certificate and X.509 swiss‑army knife

cert is a small command‑line tool for inspecting and working with X.509/TLS certificates and connections. It consolidates several utilities from goutils into a single, ergonomic CLI.

AI notes:

• None of the code has been written with AI.
• The docs are currently largely AI-generated while I work on the tool itself.

Overview

The cert binary provides subcommands to:

• Connect to TLS endpoints and print connection details (version, cipher, peers).
• Fetch and display certificate chains or dump certificate files.
• Save a remote host's full certificate chain to PEM.
• Compute and compare Subject Key Identifiers (SKIs) for keys/certs.
• Verify certificate chains using optional custom root/intermediate bundles and optional revocation checks.

Stack and Tooling

• Language: Go (module name: cert, Go toolchain declared in go.mod).
• CLI framework: [spf13/cobra]
• Configuration: [spf13/viper] (flags + environment + optional YAML config)
• Dependencies: vendored via Go modules (go.mod, go.sum).
• Packaging/Release: [goreleaser] (see .goreleaser.yaml).
• CI: CircleCI (see badge above and .circleci/config.yml).

Requirements

• Go toolchain installed. The module currently declares:
  • go 1.25 in go.mod (use a compatible or newer Go version).
• Network access if connecting to remote TLS endpoints.

Installation

• Build a local binary:

  git clone https://github.com/kisom/cert && cd cert
  go build -o cert .

• Or install into your $GOBIN/$GOPATH/bin:

  go install github.com/kisom/cert@latest

• The releases page has binaries available.

Documentation

Overview

Copyright © 2025 K. Isom <kyle@imap.cc>