hush/vendor/github.com/prometheus/procfs/internal/util/parse.go
jx12n 4d9a26498e hush: one-time secret links the server cannot read
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.
2026-09-03 00:08:38 -06:00

127 lines
3.0 KiB
Go

// Copyright The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package util
import (
"errors"
"os"
"strconv"
"strings"
)
// ParseUint32s parses a slice of strings into a slice of uint32s.
func ParseUint32s(ss []string) ([]uint32, error) {
us := make([]uint32, 0, len(ss))
for _, s := range ss {
u, err := strconv.ParseUint(s, 10, 32)
if err != nil {
return nil, err
}
us = append(us, uint32(u))
}
return us, nil
}
// ParseUint64s parses a slice of strings into a slice of uint64s.
func ParseUint64s(ss []string) ([]uint64, error) {
us := make([]uint64, 0, len(ss))
for _, s := range ss {
u, err := strconv.ParseUint(s, 10, 64)
if err != nil {
return nil, err
}
us = append(us, u)
}
return us, nil
}
// ParsePInt64s parses a slice of strings into a slice of int64 pointers.
func ParsePInt64s(ss []string) ([]*int64, error) {
us := make([]*int64, 0, len(ss))
for _, s := range ss {
u, err := strconv.ParseInt(s, 10, 64)
if err != nil {
return nil, err
}
us = append(us, &u)
}
return us, nil
}
// Parses a uint64 from given hex in string.
func ParseHexUint64s(ss []string) ([]*uint64, error) {
us := make([]*uint64, 0, len(ss))
for _, s := range ss {
u, err := strconv.ParseUint(s, 16, 64)
if err != nil {
return nil, err
}
us = append(us, &u)
}
return us, nil
}
// ReadUintFromFile reads a file and attempts to parse a uint64 from it.
func ReadUintFromFile(path string) (uint64, error) {
data, err := os.ReadFile(path)
if err != nil {
return 0, err
}
return strconv.ParseUint(strings.TrimSpace(string(data)), 10, 64)
}
// ReadIntFromFile reads a file and attempts to parse a int64 from it.
func ReadIntFromFile(path string) (int64, error) {
data, err := os.ReadFile(path)
if err != nil {
return 0, err
}
return strconv.ParseInt(strings.TrimSpace(string(data)), 10, 64)
}
// ParseBool parses a string into a boolean pointer.
func ParseBool(b string) *bool {
var truth bool
switch b {
case "enabled":
truth = true
case "disabled":
truth = false
default:
return nil
}
return &truth
}
// ReadHexFromFile reads a file and attempts to parse a uint64 from a hexadecimal format 0xXX.
func ReadHexFromFile(path string) (uint64, error) {
data, err := os.ReadFile(path)
if err != nil {
return 0, err
}
hexString := strings.TrimSpace(string(data))
if !strings.HasPrefix(hexString, "0x") {
return 0, errors.New("invalid format: hex string does not start with '0x'")
}
return strconv.ParseUint(hexString[2:], 16, 64)
}