4d9a26498e
Paste a secret, get a link, send it. The first person to open it and press
Reveal sees the secret; the link dies at that moment. The recipient needs a
browser and nothing else — no account, no client, no installed tooling.
The server cannot read what it stores. AES-256-GCM happens in the browser and
the key lives in the URL fragment, which browsers never transmit, so hushd
holds ciphertext and no key material. That is a property of where the key sits
rather than a promise about our conduct, which is why there is deliberately no
endpoint accepting a plaintext secret and no server-side-encryption fallback:
two guarantees behind one URL would be worse than one honest guarantee.
Three decisions carry the design:
* GET /s/{id} touches NO storage, not even to check existence. Slack, Teams,
WhatsApp, iMessage and Outlook Safe Links all fetch a URL before a human
sees it, so destroying on GET would destroy most secrets in transit and the
recipient's "already used" would be indistinguishable from interception.
Only POST /reveal consumes. Bot user-agent detection is an arms race;
removing the side effect from GET is not. Pinned by
TestGettingTheRevealPageNeverConsumesTheSecret.
* Destruction is one Redis GETDEL, which is atomic. GET-then-DEL has a window
where two simultaneous readers both win, and for a one-time secret that
window is the product. The store contract demands atomicity and the same
concurrency test runs against both implementations.
* Missing, already-revealed, expired and evicted are ONE indistinguishable
410. Separating them would confirm to a prober that a given link was real.
The secret id IS the capability, so secret.ID is a struct whose every
accidental path — %v, %s, String(), slog, json.Marshal — emits a redacted
handle or refuses, and the raw value needs an explicit Value(). The first
version tried to prevent leaks by implementing no String() at all; its own test
caught that Go's fmt prints unexported fields anyway, so forbidding the method
had removed the control rather than the leak.
Operationally: structured JSON on stdout in the fleet's wire format, which
Vector already collects with no annotation; six hush_* metrics on the chassis
registry with no id, IP or path in any label; five alert rules wired into
vmalert. The public Ingress enumerates /, /s/ and /api/ so /metrics, /healthz
and /readyz share the port but are unreachable from the internet — no
basic-auth middleware to maintain and get wrong.
Dependencies are vendored because go-chassis is private: the Woodpecker test
step and the in-cluster Kaniko build both run -mod=vendor with GOPROXY=off and
hold no git credential.
cmd/hush-mcp is a stdio MCP server doing the same client-side crypto locally,
so using hush from an agent preserves the same guarantee as using it from a
browser.
|
||
|---|---|---|
| .. | ||
| collectors | ||
| internal | ||
| promhttp | ||
| .gitignore | ||
| build_info_collector.go | ||
| collector.go | ||
| collectorfunc.go | ||
| counter.go | ||
| desc.go | ||
| doc.go | ||
| expvar_collector.go | ||
| fnv.go | ||
| gauge.go | ||
| get_pid_gopherjs.go | ||
| get_pid.go | ||
| go_collector_latest.go | ||
| go_collector.go | ||
| histogram.go | ||
| labels.go | ||
| metric.go | ||
| num_threads_gopherjs.go | ||
| num_threads.go | ||
| observer.go | ||
| process_collector_darwin.go | ||
| process_collector_mem_cgo_darwin.c | ||
| process_collector_mem_cgo_darwin.go | ||
| process_collector_mem_nocgo_darwin.go | ||
| process_collector_not_supported.go | ||
| process_collector_procfsenabled.go | ||
| process_collector_windows.go | ||
| process_collector.go | ||
| README.md | ||
| registry.go | ||
| summary.go | ||
| timer.go | ||
| untyped.go | ||
| value.go | ||
| vec.go | ||
| vnext.go | ||
| wrap.go | ||
See 
.