Files
bookhoard/internal/middleware/security_headers.go
T
John O'Keefe 4c43caa639 fix(search): dropdown dead on htmx-less pages; Alpine-side debounce; auto bundle stamps
The "top search bar doesn't work" report had TWO stacked causes, found
by reproducing with real keypress-by-keypress typing instead of
Playwright's fill() (which fires a single input event and masked both):

1. htmx.min.js was included PER PAGE. The header's live search is
   htmx-driven on every page, but five pages rendering @Header —
   series, admin, admin hash-conflicts, admin processing-issues,
   browse-detail — never loaded it: the input's hx-* attributes were
   inert (htmx-internal-data absent), so typing produced no request at
   all. The include now lives in the header partial itself (classic
   script, before the module bundle); the sixteen per-page copies on
   @Header pages are removed (double-processing guard). Non-header
   pages (login/register/setup/reader/index) keep their own.

2. htmx's delay: modifier on a PROGRAMMATICALLY dispatched custom event
   (htmx.trigger) loses the request entirely under rapid successive
   triggers — every re-fire canceled the pending timer and the last
   never issued, so fast typing (the normal kind) never opened the
   dropdown while one-shot fill() worked. The debounce moved into the
   Alpine component (client-local state, where it belongs); htmx now
   executes the bare `search` event immediately.

Also made bundle staleness structurally impossible: each bundle's
script stamp is a content hash computed at startup (templates/
bundles.go), so a rebuild that changes bundle bytes changes its cache
key with no manual ?v=N bump — the manual stamp was how the first
dropdown fix stayed invisible for a deploy. The reader bundle (never
stamped at all) is covered too. HTML pages additionally send
Cache-Control: no-cache (they are dynamic), so a stale page can no
longer reference a stale stamp; /api, /static and /uploads keep their
native caching, pinned by a middleware test.
2026-10-27 23:33:52 -04:00

68 lines
3.1 KiB
Go

package middleware
import (
"strings"
"github.com/labstack/echo/v5"
)
// ScriptHashThemeFlashGuard is the CSP script-src hash of the theme flash
// guard's inline script (the app's only inline script). Enforced against
// the rendered component by security_headers_test.go.
const ScriptHashThemeFlashGuard = "'sha256-JYIVpFyKdLUtWizMha0v69f6yHds+GbJRBWjvpuECBY='"
// SecurityHeadersMiddleware adds security headers to all responses.
// It also forces HTML pages to revalidate (Cache-Control: no-cache):
// SSR pages are dynamic, and heuristic browser caching of a PAGE let a
// stale page reference a stale main.js stamp long after the bundle was
// fixed — the "search dropdown still broken" report was exactly that.
// /api, /static and /uploads keep their own (or absent) caching: the
// stamped bundles are content-frozen by URL, media files are immutable
// by path.
func SecurityHeadersMiddleware() echo.MiddlewareFunc {
return func(next echo.HandlerFunc) echo.HandlerFunc {
return func(c *echo.Context) error {
// Add security headers
c.Response().Header().Set("X-Content-Type-Options", "nosniff")
c.Response().Header().Set("X-Frame-Options", "DENY")
c.Response().Header().Set("X-XSS-Protection", "1; mode=block")
c.Response().Header().Set("Strict-Transport-Security", "max-age=31536000; includeSubDomains; preload")
// script-src notes: 'unsafe-inline' is required by the pre-paint
// CSP-safe Alpine build (@alpinejs/csp) needs no eval — do NOT
// add 'unsafe-eval' here without removing that build.
//
// The inline script allow-list: the theme flash guard is the
// ONLY inline script in the app, and its byte-stable content is
// hashed into script-src (sha256 of the bytes between the
// script tags as rendered by
// templates.ThemeFlashGuard()). Editing the guard requires
// recomputing the hash — enforced by
// internal/middleware/security_headers_test.go, which renders
// the component and asserts the hash matches.
//
// style-src keeps 'unsafe-inline' for htmx-injected styles and
// Alpine :style attribute writes.
// font/img blob: — the reader renders EPUB-embedded fonts and
// images from blob: URLs inside the foliate content frame.
c.Response().Header().Set("Content-Security-Policy", "default-src 'self'; script-src 'self' "+ScriptHashThemeFlashGuard+"; style-src 'self' 'unsafe-inline'; img-src 'self' data: https: blob:; font-src 'self' data: blob:; frame-src 'self' blob:")
c.Response().Header().Set("Referrer-Policy", "strict-origin-when-cross-origin")
c.Response().Header().Set("Permissions-Policy", "geolocation=(), microphone=(), camera=()")
// Pages must always revalidate (see doc comment). The check
// runs BEFORE next(): once a templ handler writes the body,
// response headers are already on the wire.
switch p := c.Request().URL.Path; {
case strings.HasPrefix(p, "/api/"),
strings.HasPrefix(p, "/static/"),
strings.HasPrefix(p, "/uploads/"),
p == "/health":
// Not a page: keep native caching behavior.
default:
c.Response().Header().Set("Cache-Control", "no-cache")
}
return next(c)
}
}
}