Security - Category - arleo.euhttps://www.arleo.eu/en/categories/security/Security - Category - arleo.euHugo -- gohugo.ioenThu, 28 May 2026 23:45:41 +0200CSP A+ on Hugo + Cloudflare: from hash-based to origin allowlist, auto-monitoring and hardeninghttps://www.arleo.eu/en/posts/csp-a-plus-hugo-cloudflare-origin-allowlist/Thu, 28 May 2026 23:45:41 +0200Jmrhttps://www.arleo.eu/en/posts/csp-a-plus-hugo-cloudflare-origin-allowlist/

Context

arleo.eu runs on Hugo (KVM VM) → OpenResty (NUC) → Cloudflare (CDN/WAF). Goal: A+ score on Mozilla Observatory with a strict CSP that resists edge-side injections.

The journey went through three strategies over a few weeks — nonces, hashes, then origin allowlist — before landing on a stable, automated solution.

Act 1: why hash-based failed

The initial idea seemed solid: Hugo Pipes externalizes all JS with SRI, we list the hashes in the CSP, clean result. In practice, two problems made the approach impossible.

]]>SRI on Hugo: automated hashes, auto-update and BetterStack alertinghttps://www.arleo.eu/en/posts/sri-cdn-hugo-automate/Sun, 17 May 2026 00:00:00 +0000Jmrhttps://www.arleo.eu/en/posts/sri-cdn-hugo-automate/

Why SRI?

When your site loads resources from a third-party CDN — FontAwesome, Mermaid, Animate.css — you’re trusting an external party you have no control over. If jsdelivr.net gets compromised, or if a supposedly immutable version is silently mutated, your site can become an attack vector.

Subresource Integrity (SRI) solves this cleanly: every <link> or <script> tag carries an integrity="sha256-…" attribute that the browser verifies before executing the resource. If the hash doesn’t match, the browser blocks the load.

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