Sebastian Erhart

Sebastian Erhart is the independent developer behind lego, a lightweight, open-source ACME client and library written in Go that streamlines the automatic issuance, renewal, and revocation of TLS certificates from any ACME-compliant Certificate Authority, with first-class support for Let’s Encrypt. Built for DevOps pipelines, containerized micro-services, and embedded edge devices, the tool exposes both a command-line interface and a reusable Go package, enabling administrators to script unattended certificate lifecycles inside Docker, Kubernetes, systemd timers, or CI/CD workflows. Its modular architecture ships with more than 150 DNS providers—from Cloudflare, Route 53, and Azure DNS to exotic registrars—so wildcard and apex domains can be validated through DNS-01 challenges without opening port 80. HTTP-01 and TLS-ALPN-01 challenges are equally supported for traditional web servers such as Apache, Nginx, Caddy, and Traefik. lego’s deterministic folder layout produces standardized certificate bundles (PEM chain, private key, and .pfx) that are immediately consumable by reverse proxies, mail servers, load balancers, Java keystores, or Go applications themselves. Advanced features include ECDSA key generation, OCSP stapling, external account binding for commercial CAs, and concurrent safe renewal logic that prevents rate-limit penalties. Because the entire codebase is cross-platform and dependency-free, it can be compiled into a single static binary for Windows, Linux, macOS, or BSD, making it a popular choice for automated certificate management in cloud, on-premise, and IoT environments. All releases of Sebastian Erhart’s lego are available for free on get.nero.com, where downloads are delivered through trusted Windows package sources such as winget, always install the latest version, and can be queued for batch installation alongside other applications.