moshpit: publish the keys a name may present

apps/pwa/src/migrations/009_moshpit_pins.sql

@@ -0,0 +1,28 @@
+-- The keys a name is allowed to present.
+--
+-- Per name rather than per TLD, and that is forced by 008: names under a TLD
+-- are sold, so `blue.eggs` can belong to someone who does not own `.eggs`.
+-- Hanging keys off the TLD would let its operator publish a key for a name they
+-- already sold — impersonating a buyer inside the namespace they bought into.
+-- The pin therefore lives beside the name and is authorised by the name's owner.
+--
+-- `kind` keeps the transports apart. A `tls` pin covers a certificate's
+-- SubjectPublicKeyInfo; an `mtp` pin covers an ML-DSA-65 identity. Both are
+-- SHA-256 over an SPKI, so as strings they are indistinguishable, and nothing
+-- but this column stops a client being handed the wrong one and failing with no
+-- diagnosable reason.
+--
+-- Several rows per (tld, label, kind) on purpose: a key cannot rotate without a
+-- window in which the old and the new one are both published.
+CREATE TABLE IF NOT EXISTS moshpit_name_pins (
+  tld        TEXT NOT NULL,
+  label      TEXT NOT NULL,
+  pin        TEXT NOT NULL,
+  kind       TEXT NOT NULL CHECK (kind IN ('tls','mtp')),
+  note       TEXT,
+  user_id    TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+  created_at INTEGER NOT NULL,
+  PRIMARY KEY (tld, label, pin)
+);
+CREATE INDEX IF NOT EXISTS idx_moshpit_name_pins ON moshpit_name_pins(tld, label, kind);
+CREATE INDEX IF NOT EXISTS idx_moshpit_name_pins_user ON moshpit_name_pins(user_id);

apps/pwa/src/moshpit.mjs

@@ -248,6 +248,12 @@ export async function setNameTarget({ tld: tldInput, label: labelInput, userId,
 export async function releaseName({ tld: tldInput, label: labelInput, userId }) {
   const owned = await ownedName(tldInput, labelInput, userId);
   if (!owned.ok) return owned;
+  // Keys go with the name. Deleted explicitly rather than left to the foreign
+  // key, because SQLite only enforces those with `PRAGMA foreign_keys = ON`
+  // and nothing here sets it — so a cascade that looks declared would not fire,
+  // and whoever registered the name next would inherit the previous holder's
+  // published keys.
+  await run(`DELETE FROM moshpit_name_pins WHERE tld = ? AND label = ?`, [owned.tld, owned.label]);
   await run(`DELETE FROM moshpit_names WHERE tld = ? AND label = ?`, [owned.tld, owned.label]);
   await logAction(owned.tld, userId, `unname:${owned.label}`);
   return { ok: true };
@@ -431,3 +437,120 @@ export async function resolveMoshpitName(input) {
     target: entry?.target ?? null,
   };
 }
+
+/* ---- the keys a name may present ---- */
+
+const PIN_COLS = `tld, label, pin, kind, note, user_id, created_at`;
+
+export const PIN_KINDS = ["tls", "mtp"];
+
+/**
+ * A pin is SHA-256 over a SubjectPublicKeyInfo, base64 — always 32 bytes, so
+ * always 44 characters ending in one '='. Checked rather than trusted, because
+ * a malformed pin is indistinguishable in effect from a key that simply never
+ * matches: the connection fails, and nothing anywhere says why.
+ */
+export function isPin(value) {
+  if (typeof value !== "string" || !/^[A-Za-z0-9+/]{43}=$/.test(value)) return false;
+  return Buffer.from(value, "base64").length === 32;
+}
+
+export function normalizePinKind(value) {
+  const kind = String(value ?? "").trim().toLowerCase();
+  return PIN_KINDS.includes(kind) ? kind : null;
+}
+
+export async function listPins(tldInput, labelInput, kind = null) {
+  const tld = normalizeTld(tldInput);
+  const label = normalizeLabel(labelInput);
+  if (!tld || !label) return [];
+  return kind
+    ? all(`SELECT ${PIN_COLS} FROM moshpit_name_pins WHERE tld = ? AND label = ? AND kind = ?
+           ORDER BY created_at DESC`, [tld, label, kind])
+    : all(`SELECT ${PIN_COLS} FROM moshpit_name_pins WHERE tld = ? AND label = ?
+           ORDER BY kind, created_at DESC`, [tld, label]);
+}
+
+/**
+ * The keys a client should accept for `scrambled.eggs`.
+ *
+ * Aliases are followed first. When `.agentic` points at `.agent`, a client
+ * asking about `foo.agentic` connects to whatever serves `foo.agent`, so the
+ * keys that matter are the ones published there. Answering with the typed
+ * name's own pins would refuse every working connection.
+ *
+ * Returns null when the pit has no authority over the name at all — an
+ * unclaimed TLD is not a Moshpit name, and saying "no key published" about
+ * `example.com` would invite a client to treat clearnet as merely unpinned.
+ */
+export async function pinsForName(input, kind = null) {
+  const resolution = await resolveMoshpitName(input);
+  if (!resolution || !resolution.registered) return null;
+
+  const parsed = parseMoshpitName(resolution.resolved);
+  if (!parsed) return null;
+
+  return {
+    name: resolution.name,
+    resolved: resolution.resolved,
+    tld: parsed.tld,
+    label: parsed.label,
+    name_registered: resolution.name_registered,
+    target: resolution.target,
+    pins: await listPins(parsed.tld, parsed.label, kind),
+  };
+}
+
+/** Publish a key for a name you hold. */
+export async function addPin({ tld: tldInput, label: labelInput, pin, kind: kindInput, note = null, userId }) {
+  const owned = await ownedName(tldInput, labelInput, userId);
+  if (!owned.ok) return owned;
+
+  if (!isPin(pin)) {
+    return { ok: false, error: "pin must be base64 SHA-256 over a SubjectPublicKeyInfo (44 characters)" };
+  }
+  const kind = normalizePinKind(kindInput);
+  if (!kind) return { ok: false, error: `kind must be one of ${PIN_KINDS.join(", ")}` };
+
+  // The same pin under a second kind is a mistake worth naming. Ignoring it
+  // would leave the operator sure they published an `mtp` key while every
+  // client is still told it is `tls`.
+  const existing = await get(
+    `SELECT kind FROM moshpit_name_pins WHERE tld = ? AND label = ? AND pin = ?`,
+    [owned.tld, owned.label, pin],
+  );
+  if (existing && existing.kind !== kind) {
+    return { ok: false, error: `that pin is already published for ${owned.label}.${owned.tld} as ${existing.kind}`, taken: true };
+  }
+  if (existing) return { ok: true };
+
+  const trimmed = typeof note === "string" && note.trim() ? note.trim().slice(0, 200) : null;
+  await run(
+    `INSERT INTO moshpit_name_pins (${PIN_COLS}) VALUES (?,?,?,?,?,?,?)`,
+    [owned.tld, owned.label, pin, kind, trimmed, userId, Date.now()],
+  );
+  await logAction(owned.tld, userId, `pin:add:${owned.label}:${kind}`);
+  return { ok: true };
+}
+
+/**
+ * Withdraw a key.
+ *
+ * Removing the last pin of a kind is allowed. It leaves the name with no key
+ * published, which clients treat as a refusal rather than as permission — so
+ * this is how a compromised key is taken out of service, and refusing it on the
+ * grounds that it breaks connections would be refusing the point.
+ */
+export async function removePin({ tld: tldInput, label: labelInput, pin, userId }) {
+  const owned = await ownedName(tldInput, labelInput, userId);
+  if (!owned.ok) return owned;
+
+  const result = await run(
+    `DELETE FROM moshpit_name_pins WHERE tld = ? AND label = ? AND pin = ?`,
+    [owned.tld, owned.label, pin],
+  );
+  if (!result.rowsAffected) return { ok: false, error: "that pin is not published for this name" };
+
+  await logAction(owned.tld, userId, `pin:remove:${owned.label}`);
+  return { ok: true };
+}

apps/pwa/src/routes/moshpit.mjs

@@ -19,12 +19,38 @@ import { balance } from "../lib/credits.mjs";
 import { resolverConfig } from "../lib/moshpit-resolvers.mjs";
 import { landingFor } from "../lib/moshpit-landing.mjs";
 import {
-  getTld, listTlds, listTldsForUser, registerTld, normalizeLabel,
-  setAlias, clearAlias, listExempt, setExempt, clearExempt,
-  listNames, getName, getTldWithPrice, registerName, setNameTarget, releaseName,
-  setTldPrice, listTldsNotOwnedBy, quoteName, openNamePurchase,
-  resolveMoshpitName, normalizeTld, tldRejection, parseMoshpitName,
-  normalizeMode, resolutionPreference,
+  addPin,
+  clearAlias,
+  clearExempt,
+  getName,
+  getTld,
+  getTldWithPrice,
+  listExempt,
+  listNames,
+  listPins,
+  listTlds,
+  listTldsForUser,
+  listTldsNotOwnedBy,
+  normalizeLabel,
+  normalizeMode,
+  normalizePinKind,
+  normalizeTld,
+  openNamePurchase,
+  parseMoshpitName,
+  PIN_KINDS,
+  pinsForName,
+  quoteName,
+  registerName,
+  registerTld,
+  releaseName,
+  removePin,
+  resolutionPreference,
+  resolveMoshpitName,
+  setAlias,
+  setExempt,
+  setNameTarget,
+  setTldPrice,
+  tldRejection,
 } from "../moshpit.mjs";
 import { config } from "../config.mjs";
 
@@ -150,6 +176,94 @@ moshpitRouter.delete("/api/moshpit/tlds/:tld/names", async (req, res) => {
   res.json({ tld: normalizeTld(req.params.tld), label: normalizeLabel(req.body?.label), released: true });
 });
 
+/* ---- the keys a name may present ---- */
+
+/**
+ * GET /api/moshpit/pins?name=scrambled.eggs[&kind=tls] — public.
+ *
+ * The lookup every Moshpit client makes before it will talk to anything. The
+ * status codes carry meaning the body does not, because clients cache on them:
+ *
+ *   400  not a Moshpit name      a definite no, cacheable as long as a real answer
+ *   404  no key published        also definite — nobody has vouched for a key here
+ *   200  { pins: [...] }         the keys a peer may present
+ *
+ * What matters is that both differ from a 5xx or a timeout. A definite no means
+ * refuse the connection; an outage means try again later. A client that treats
+ * them alike either fails closed forever or fails open once, and the second is
+ * how pinning gets quietly defeated.
+ */
+moshpitRouter.get("/api/moshpit/pins", async (req, res) => {
+  const name = String(req.query.name ?? "").trim();
+  if (!name) return bad(res, "name is required");
+
+  const requested = req.query.kind ? String(req.query.kind) : null;
+  const kind = requested ? normalizePinKind(requested) : null;
+  if (requested && !kind) return bad(res, `kind must be one of ${PIN_KINDS.join(", ")}`);
+
+  const found = await pinsForName(name, kind);
+  if (!found) return bad(res, "not a Moshpit name");
+
+  const body = {
+    name: found.name,
+    resolved: found.resolved,
+    tld: found.tld,
+    label: found.label,
+    target: found.target,
+    // A flat array of strings first: that is all a client needs in order to
+    // compare against what a peer actually presented.
+    pins: found.pins.map((p) => p.pin),
+    entries: found.pins.map((p) => ({ pin: p.pin, kind: p.kind, note: p.note })),
+  };
+  return found.pins.length ? res.json(body) : res.status(404).json(body);
+});
+
+/** GET /api/moshpit/tlds/:tld/pins?label=blue — public; pins are public by nature. */
+moshpitRouter.get("/api/moshpit/tlds/:tld/pins", async (req, res) => {
+  const tld = normalizeTld(req.params.tld);
+  const label = normalizeLabel(req.query.label);
+  if (!tld || !label) return bad(res, "tld and label are required");
+
+  const requested = req.query.kind ? String(req.query.kind) : null;
+  const kind = requested ? normalizePinKind(requested) : null;
+  if (requested && !kind) return bad(res, `kind must be one of ${PIN_KINDS.join(", ")}`);
+
+  res.json({ tld, label, pins: await listPins(tld, label, kind) });
+});
+
+/**
+ * POST /api/moshpit/tlds/:tld/pins { label, pin, kind, note? } — publish a key.
+ *
+ * Adds rather than replaces, so rotation has a window: publish the new key
+ * alongside the old, deploy it, then withdraw the old. Replacing outright would
+ * break every client between the write and the deploy.
+ */
+moshpitRouter.post("/api/moshpit/tlds/:tld/pins", async (req, res) => {
+  if (!req.user) return unauthorized(res);
+  const result = await addPin({
+    tld: req.params.tld,
+    label: req.body?.label,
+    pin: req.body?.pin,
+    kind: req.body?.kind,
+    note: req.body?.note,
+    userId: req.user.id,
+  });
+  // 409 when the pin is already published under another kind: the request was
+  // well formed, it just contradicts what is already there.
+  if (!result.ok) return bad(res, result.error || "could not publish that pin", result.taken ? 409 : 400);
+  res.status(201).json({ tld: normalizeTld(req.params.tld), label: normalizeLabel(req.body?.label), kind: req.body?.kind });
+});
+
+/** DELETE /api/moshpit/tlds/:tld/pins { label, pin } — withdraw a key. */
+moshpitRouter.delete("/api/moshpit/tlds/:tld/pins", async (req, res) => {
+  if (!req.user) return unauthorized(res);
+  const result = await removePin({
+    tld: req.params.tld, label: req.body?.label, pin: req.body?.pin, userId: req.user.id,
+  });
+  if (!result.ok) return bad(res, result.error || "could not withdraw that pin", 404);
+  res.json({ tld: normalizeTld(req.params.tld), label: normalizeLabel(req.body?.label), withdrawn: true });
+});
+
 /* ---- the market ---- */
 
 /** TLDs other people hold. `?for_sale=1` narrows to the buyable ones. */