Edge hardening

The HTTP-facing layer between the internet and your application. Pairs with host-hardening for the box itself, app-deployment for what sits behind it, and data-tier-hardening for the persistence layer further back. Read the TLS piece first if you are configuring a new edge; read the rate-limiting piece after you have seen your first real auth-endpoint burst.

tls-audit

What this script does tls-audit runs a read-only audit against a deployed HTTPS endpoint and reports on each item from the Nginx TLS 2026 guide and the nginx-tls config generator: Protocol support — TLS 1.0 and 1.1 should be rejected; TLS 1.2 and 1.3 should be accepted. Certificate — covers the hostname, not expired (and not expiring in the next 21 days), modern key algorithm, complete chain with at least one intermediate, not self-signed. OCSP stapling — the server should be stapling an OCSP response. HSTS — Strict-Transport-Security header present, max-age of at least one year, includeSubDomains directive set, preload flagged if present (informational, not a recommendation). Security headers — X-Content-Type-Options: nosniff and Referrer-Policy present; a Server header that leaks a version number is flagged. It uses only openssl s_client, curl, and standard text tools — no external scanner like testssl.sh required. Designed to run from a machine other than the host being audited, with no privilege. ...

Nginx Rate Limiting — limit_req, limit_conn, and fail2ban

Tested on: Ubuntu 24.04 LTS, Nginx 1.26.x (nginx.org stable repository). All directives are core Nginx — no third-party modules required. Why this matters A web tier with no rate limiting fails in three predictable ways: Authentication brute force. A WordPress, application, or admin-panel login form with no rate cap is one credential-stuffing tool away from compromise. Signup / forgot-password abuse. Endpoints that send email, provision accounts, or issue tokens are expensive and attractive to spammers. Single-tenant noise becomes shared-tenant outage. One misbehaving client (or one bot) hammering an endpoint can starve FPM workers, application-server threads, and database connections. Rate limiting is not DDoS protection — that lives at the CDN / WAF layer if you need it. Nginx rate limiting is for the predictable, day-to-day class of behaviour: too many requests from too few sources to too few endpoints. Get this right and your origin survives even when something at the edge fails. ...

Nginx TLS Configuration — 2026 Baseline

Tested on: Ubuntu 24.04 LTS, Nginx 1.26.x (from nginx.org stable repository), Let’s Encrypt via certbot 2.x. The same config works on RHEL 9 / AlmaLinux 9 with path adjustments noted inline. Why this matters Most Nginx TLS configurations on the internet were copy-pasted from a tutorial written three to seven years ago. That means they typically have one or more of the following problems: TLS 1.0 and 1.1 still enabled “for compatibility” with browsers that no longer exist. A hand-rolled cipher list that excludes modern AEAD suites or includes long-deprecated ones (3DES, RC4, CBC-mode without AEAD). ssl_prefer_server_ciphers on — which was correct advice once but is now the wrong default for TLS 1.3. No OCSP stapling, so every visitor’s browser does a side-channel OCSP lookup to the CA on first connection. HSTS missing, or HSTS set without includeSubDomains on a domain that has subdomains people forgot about. HTTP-only Strict-Transport-Security header (it must be served over HTTPS to be honoured at all). This guide gives you a single, opinionated baseline that addresses all of the above. It targets the Mozilla “Intermediate” profile — broad client compatibility without enabling anything embarrassing. ...