kv-wasm: onboarding (setup codes, enrollment tickets, scan-to-join) for the web vault

Mirrors kv-ffi's docs/10 §5 API in WebCore and binds it under the names the web app codes
against: setupPayloadForKit, addDevicePayload, revokeEnrollmentTicket, loginWithSetup,
joinStart/joinPoll/joinCancel, joinApprove, joinSend, and the free function parseSetupPayload
(also callable through the worker client).

Unlike kv-ffi, the Secret Key is not persisted: every unlock on the web takes it, so it is
kept zeroized in the unlocked state and dropped on lock. loginWithSetup refuses a code for a
different server than the configured origin (the browser only talks to its own origin).

Tests: ticket enrollment and scan-to-join in both roles against kv-ffi via the kv-sync test
server, a swapped-approver rejection, a Chrome test (IndexedDB never holds the Secret Key,
JS shapes, error codes) and a Node smoke check of the built package.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

crates/kv-wasm/js/client.d.ts

@@ -6,6 +6,7 @@ import type {
   totpCode,
   matchUrl,
   coreVersion,
+  parseSetupPayload,
 } from "./kv_wasm.js";
 
 export * from "./kv_wasm.js";
@@ -22,6 +23,7 @@ export type RemoteVault = CoreMethods & {
   totpCode: Async<typeof totpCode>;
   matchUrl: Async<typeof matchUrl>;
   coreVersion: Async<typeof coreVersion>;
+  parseSetupPayload: Async<typeof parseSetupPayload>;
   /** Frees the core (zeroizing keys), releases the tab lock and terminates the worker. */
   close(): Promise<void>;
 };

crates/kv-wasm/js/smoke.mjs

@@ -92,6 +92,21 @@ assert.equal(kv.generatePassword(20, false).length, 20);
 const exported = await a.exportEncrypted("export passphrase");
 assert.ok(exported instanceof Uint8Array && exported.length > 100);
 
+// Onboarding (docs/10): the Kit's Setup Code round-trips through the free parser.
+const k = await kv.VaultCore.newInMemory();
+const kSecret = await k.createAccount(PW);
+await k.configureServer("https://vault.example.org", []);
+const setup = kv.parseSetupPayload(await k.setupPayloadForKit());
+assert.deepEqual(setup, {
+  serverUrl: "https://vault.example.org",
+  spkiPins: [],
+  accountId: await k.accountId(),
+  secretKey: kSecret,
+  ticket: null,
+});
+await rejects(k.joinPoll(), "Invalid");
+k.free();
+
 if (process.argv.includes("--write-fixture")) {
   const items = [];
   for (const s of await a.listItems()) items.push(await a.getItem(s.id));

crates/kv-wasm/js/worker.js

@@ -56,7 +56,7 @@ async function open(dbName, inMemory) {
   return null;
 }
 
-const FREE_FUNCTIONS = new Set(["generatePassword", "totpCode", "matchUrl", "coreVersion"]);
+const FREE_FUNCTIONS = new Set(["generatePassword", "totpCode", "matchUrl", "coreVersion", "parseSetupPayload"]);
 
 self.onmessage = async ({ data: { id, method, args } }) => {
   try {