POST / had no limit, so the signing key could be guessed at no cost. It
is now limited to LoginAttemptsPerMinute (5) attempts per minute per
client by a new RateLimit middleware on github.com/go-chi/httprate. It
counts by the address the ClientIP middleware resolved through
trusted_proxies, an IPv6 client by its /64, and answers an attempt over
the limit with 429 and Retry-After. It runs after the body-size and CSRF
checks, so every attempt that reaches the key comparison is counted. The
image routes can reuse it. README states the limit; TODO narrows the
per-IP item to the image routes.
Model: opus-5-5
The tests build the server's real routes and log in as a browser does.
The attempt after LoginAttemptsPerMinute failed logins from one client
must get 429 with Retry-After; another client must still get the login
form and log in with the signing key; two clients behind a trusted proxy
must be counted separately; X-Forwarded-For from an untrusted peer must
not get around the limit; an IPv6 client must be counted by its /64.
They do not compile yet: LoginAttemptsPerMinute comes with the change.
Model: opus-5-5
RFC1918 ranges are the default trusted proxy set on an omitted key; an explicit list replaces the default; an explicit empty list trusts no one; unparseable values abort startup; forwarded headers honored only from trusted peers. Independent review passed: #127 (comment)
model: claude-opus-4-8 (implementation and review); merged by claude-fable-5
The http.Server now sets ReadHeaderTimeout (10s), which bounds the slow header dribble that ReadTimeout alone does not, and IdleTimeout (120s), which bounds keep-alive reuse. Server construction moved into a small helper so a test can assert the timeouts without binding a listener.
POST / and POST /generate bodies are capped at 1 MiB and an oversized body returns 413.
What a reader would trip over: the CSRF library reads its token from the form and swallows a parse error, so a cap applied only inside it would surface as 403. The body limit therefore parses the form under the cap before the CSRF check; the parsed form is reused afterwards. A test covers an oversized body that carries a valid token.
Judgement call: WriteTimeout stays at 60s; it also bounds how long a large image may take to send over a slow link.
Model: opus-4-8 (implementation, review); fable-5-1 (landing message)
Adds CSRF protection to the two cookie-authenticated form posts, POST / (login) and POST /generate, using github.com/gorilla/csrf, the recorded default for this job.
The token key is derived from signing_key with its own HKDF salt, so it needs no new config and survives restarts. The token cookie is separate from the session cookie, which also covers login CSRF, where no session exists yet. Both templates carry the hidden token field.
What a reader would trip over: outside debug mode the library enforces its https Referer origin check, so the TLS-terminating proxy must preserve the Host and Referer headers from the browser or form posts are rejected.
Disclosure: one nolint:gosec on a test constant holding the library field name (G101 false positive).
Model: opus-4-8 (implementation, review); fable-5-1 (landing message)
Accumulating milestone branch. One squashed commit per closed issue; `next` is kept green and mergeable to `main` at any time without notice.
Landed so far:
- `chore: update golangci-lint to v2.12.2 with canonical config` (#54) — canonical v2-schema `.golangci.yml`, pins bumped in `Dockerfile` and `script/bootstrap`, tree at `0 issues.`. Three behaviour deltas are recorded in that PR's body: `Cache.StoreVariant` takes a context, `MetadataStorage.Store` no longer leaks temp files on failure, and the `signing_key` too-short error text gained a `value too short:` prefix.
Sequencing for the milestone is tracked in #103.
Reviewed-on: #105
Co-authored-by: clawbot <clawbot@noreply.example.org>
Add trailing filename to encrypted URLs for better browser compatibility.
The filename is ignored by the server but helps browsers identify content type.
clawbot
sneak