fix: await NWC payment bearer commits

src/lnurlcash/nwc.fencing.cases.ts

@@ -0,0 +1,66 @@
+// Stale-owner fencing end to end: a service accepted work while its owner
+// was still installed, and a second tab replaced the saved key AFTER the
+// fence's last safe point - mid-melt, past the boundary where aborting is
+// no longer possible. What must not happen is any stale-owner WRITE:
+// no bearer changeset, no budget debit, no success response.
+
+import {describe, expect, it} from 'vitest'
+import {bytesToHex} from '@noble/hashes/utils.js'
+
+import {readNwcConnections} from './nwc'
+import {
+  methodRequest,
+  OTHER_LINKING_KEY,
+  OTHER_OWNER_ID,
+  OWNER_ID,
+  waitFor,
+} from './nwc.testProtocol'
+import {makeBearer, mint, readResponse, startTestService} from './nwc.testService'
+
+describe('service: post-boundary stale-owner fencing', () => {
+  it('makes no stale-owner writes when the saved key is replaced mid-melt', async () => {
+    // Given a running service whose next mint call coincides with a second
+    // tab installing its own wallet (the first fetch is the melt itself:
+    // the exact-match carve performs no mint call of its own)
+    const m = await mint()
+    let swapped = false
+    const swappingFetch: typeof fetch = (input, init) => {
+      if (!swapped) {
+        swapped = true
+        localStorage.setItem(
+          'sattle_linking_key',
+          JSON.stringify({
+            enc: false,
+            value: bytesToHex(OTHER_LINKING_KEY),
+            ownerId: OTHER_OWNER_ID,
+            version: 1,
+          }),
+        )
+      }
+      return fetch(input, init)
+    }
+    const {relay, walletServicePubkey, state, stop} = await startTestService({
+      kit: {fetch: swappingFetch},
+    })
+    state.bearers = [await makeBearer(m, 'd7'.repeat(32), 21_000)]
+    const request = methodRequest(walletServicePubkey, 'pay_invoice', {
+      invoice: 'lnbc210n1pjqrstuvwxyz',
+    })
+
+    // When the pay flows past the irreversible boundary and reaches the
+    // first owner-bound persistence (the conservative budget debit)
+    relay.emit(request)
+    await waitFor(() => state.errors.length > 0)
+
+    // Then the melt genuinely happened (we are past the boundary) ...
+    expect(swapped).toBe(true)
+    expect(m.state.noteState('d7'.repeat(32))).toBe('burned')
+    // ... but nothing under the stale owner moved: no budget debit, no
+    // bearer changeset, no success response (the failure surfaced through
+    // onError instead)
+    expect(readNwcConnections(OWNER_ID)[0]?.spent.msat).toBe(0)
+    expect(state.changesets).toEqual([])
+    expect(readResponse(relay.published, request.id, 'nip44_v2')).toBeNull()
+    await stop()
+  })
+})

src/lnurlcash/nwc.pay-b.cases.ts

@@ -0,0 +1,158 @@
+// The NWC wallet service end to end: connection strings and key
+// derivation, the request/response cycle over an in-memory relay (the
+// transport is injected - no network), every method against the
+// conformance mock mint, the legacy NIP-04 path, budget enforcement, and
+// the error paths. Fund-safety focus: budgets can't be exceeded, stale
+// requests never execute, and a settled preimage only ever reveals an
+// already-rotated (burned) note secret.
+
+import {afterEach, beforeEach, describe, expect, it} from 'vitest'
+import {bytesToHex, hexToBytes} from '@noble/hashes/utils.js'
+import {finalizeEvent, getPublicKey} from 'nostr-tools/pure'
+import {encrypt as nip04Encrypt, decrypt as nip04Decrypt} from 'nostr-tools/nip04'
+import {v2 as nip44v2} from 'nostr-tools/nip44'
+import {buildNoteUrl, fetchNoteInfo, noteK1} from 'lnurlcash-kit'
+import {createMockMint} from 'lnurlcash-conformance/mock-mint'
+
+import {
+  NWC_INFO_KIND,
+  NWC_REQUEST_KIND,
+  NWC_RESPONSE_KIND,
+  buildConnectionString,
+  connectionInfoOf,
+  createConnection,
+  deriveNwcWalletKey,
+  migrateLegacyNwcStorage,
+  parseConnectionString,
+  readNwcEnabled,
+  readNwcConnections,
+  startService,
+  writeNwcEnabled,
+  writeNwcConnections,
+} from './nwc'
+import type {NostrEvent, NwcConnectionRecord, NwcServiceDeps, NwcTransport} from './nwc'
+import type {NostrFilter} from './nwc/transport'
+import type {NwcChangeset} from './nwc'
+import type {Bearer} from './types'
+import {ensureSavedKeyOwner, linkingPubKeyHex, saveLinkingKey} from './keys'
+import {requiredValue, stubLocalStorage} from './test-utils'
+
+import {
+  CLIENT_PUBKEY,
+  CLIENT_SECRET,
+  FAST_POLL,
+  LINKING_KEY,
+  OTHER_LINKING_KEY,
+  OTHER_OWNER_ID,
+  OWNER_ID,
+  RELAYS,
+  STRANGER_SECRET,
+  clientRequest,
+  createFakeRelay,
+  deferred,
+  foreignConnectionFixture,
+  methodRequest,
+  nowSeconds,
+  storeForeignConnection,
+  waitFor,
+} from './nwc.testProtocol'
+import {call, makeBearer, mint, readResponse, startTestService} from './nwc.testService'
+describe('service: pay_invoice (continued)', () => {
+  it('rejects a payment over the connection budget with QUOTA_EXCEEDED', async () => {
+    const m = await mint()
+    const {relay, walletServicePubkey, state, stop} = await startTestService({
+      budgetMsat: 20_000,
+    })
+    state.bearers = [await makeBearer(m, 'ee'.repeat(32), 21_000)]
+
+    const response = await call(relay, walletServicePubkey, 'pay_invoice', {
+      invoice: 'lnbc210n1pjqrstuvwxyz',
+    })
+    expect(response.error?.code).toBe('QUOTA_EXCEEDED')
+    // nothing moved: the note is untouched, no spend recorded
+    expect(m.state.noteState('ee'.repeat(32))).toBe('outstanding')
+    expect(requiredValue(state.bearers[0]).spent).toBeUndefined()
+    expect(requiredValue(readNwcConnections(OWNER_ID)[0]).spent.msat).toBe(0)
+    await stop()
+  })
+
+  it('resets the allowance once the budget period has rolled over', async () => {
+    const m = await mint()
+    const {relay, walletServicePubkey, state, stop} = await startTestService({
+      budgetMsat: 21_000,
+      periodMs: 60_000,
+    })
+    // simulate a fully spent budget from a period that ended long ago
+    const record: NwcConnectionRecord = requiredValue(readNwcConnections(OWNER_ID)[0])
+    writeNwcConnections(OWNER_ID, [
+      {...record, spent: {periodStart: Date.now() - 120_000, msat: 21_000}},
+    ])
+    state.bearers = [await makeBearer(m, 'ef'.repeat(32), 21_000)]
+
+    const response = await call(relay, walletServicePubkey, 'pay_invoice', {
+      invoice: 'lnbc210n1pjqrstuvwxyz',
+    })
+    expect(response.error).toBeNull()
+    expect(requiredValue(readNwcConnections(OWNER_ID)[0]).spent.msat).toBe(21_000)
+    await stop()
+  })
+
+  it('rejects a payment the wallet cannot cover with INSUFFICIENT_BALANCE', async () => {
+    const m = await mint()
+    const {relay, walletServicePubkey, state, stop} = await startTestService({})
+    state.bearers = [await makeBearer(m, 'ff'.repeat(32), 5_000)]
+
+    const response = await call(relay, walletServicePubkey, 'pay_invoice', {
+      invoice: 'lnbc210n1pjqrstuvwxyz',
+    })
+    expect(response.error?.code).toBe('INSUFFICIENT_BALANCE')
+    expect(m.state.noteState('ff'.repeat(32))).toBe('outstanding')
+    await stop()
+  })
+
+  it('rejects a request amount that mismatches the invoice amount', async () => {
+    const {relay, walletServicePubkey, stop} = await startTestService({})
+    const response = await call(relay, walletServicePubkey, 'pay_invoice', {
+      invoice: 'lnbc210n1pjqrstuvwxyz',
+      amount: 5_000,
+    })
+    expect(response.error?.code).toBe('OTHER')
+    expect(response.error?.message).toMatch(/match/i)
+    await stop()
+  })
+
+  it('rejects an amount-less invoice instead of guessing', async () => {
+    const {relay, walletServicePubkey, stop} = await startTestService({})
+    const response = await call(relay, walletServicePubkey, 'pay_invoice', {
+      invoice: 'lnbc1pjqrstuvwxyz',
+    })
+    expect(response.error?.code).toBe('OTHER')
+    expect(response.error?.message).toMatch(/amount/i)
+    await stop()
+  })
+
+  it('answers a failed melt with PAYMENT_FAILED and tracks the returned funds', async () => {
+    const m = await mint({meltAlwaysFails: true})
+    const {relay, walletServicePubkey, state, stop} = await startTestService({
+      // a short verify budget: the failed melt is classified by the poll
+      // running out, and that wait is the test's own clock
+      poll: {intervalMs: 10, intervalCapMs: 20, maxWaitMs: 300},
+    })
+    state.bearers = [await makeBearer(m, '01'.repeat(32), 21_000)]
+
+    const response = await call(relay, walletServicePubkey, 'pay_invoice', {
+      invoice: 'lnbc210n1pjqrstuvwxyz',
+    })
+    expect(response.error?.code).toBe('PAYMENT_FAILED')
+
+    // the funds came back, re-secured: the old secret burned, a fresh one
+    // tracked unspent via the changeset - and no budget spend recorded
+    expect(m.state.noteState('01'.repeat(32))).toBe('burned')
+    const returned = requiredValue(state.bearers.find((b) => b.id.startsWith('added-')))
+    expect(returned.spent).toBeUndefined()
+    expect(returned.amount).toBe(21_000)
+    expect(m.state.noteState(requiredValue(noteK1(returned.url)))).toBe('outstanding')
+    expect(requiredValue(readNwcConnections(OWNER_ID)[0]).spent.msat).toBe(0)
+    await stop()
+  })
+})

src/lnurlcash/nwc/context.ts

@@ -30,11 +30,13 @@ export type NwcServiceDeps = {
   // the mint make_invoice issues invoices against (the wallet's default
   // mint - NIP-47's make_invoice carries no mint choice)
   getDefaultMint: () => string | null
+  assertCurrentOwner: () => void
   applyChangeset: (
     changeset: NwcChangeset,
     connection: NwcConnectionInfo,
-    method: NwcMethod
+    method: NwcMethod,
-  ) => void
+    assertOwner: () => void,
+  ) => Promise<void>
   transport?: NwcTransport
   // kit transport overrides (fetch injection, timeouts)
   kit?: LnurlcashOptions
@@ -73,4 +75,13 @@ export type RequestContext = {
   updateRecord: (record: NwcConnectionRecord) => void
   invoices: Map<string, PendingInvoice>
   nowSeconds: () => number
+  assertOwner: () => void
+  // Starts service-owned work only while the service accepts new work.
+  // Accepted tasks become part of stop's drain before key cleanup.
+  startBackground: (work: () => Promise<void>) => boolean
+  // fires when the service stops: long OBSERVATION waits (the invoice
+  // claim poll) must interrupt themselves on it. Work that has already
+  // reached a fund-critical commit must NOT consult it - stop awaits
+  // those tasks through its drain
+  stopSignal: AbortSignal
 }

src/lnurlcash/nwc/pay.ts

@@ -9,7 +9,7 @@ import {
   decodeBolt11AmountMsat,
   fetchInvoiceVerification,
   isBolt11Invoice,
-  noteK1
+  noteK1,
 } from 'lnurlcash-kit'
 
 import type {Bearer, NewBearer} from '../types'
@@ -29,12 +29,9 @@ import {errResult, okResult} from './protocol'
 // rotate) is left for the next refresh to reconcile, exactly as the UI
 // leaves it - the money itself sits in the re-secured note, which IS
 // tracked.
-export const payChangeset = (
+export const payChangeset = (bearers: Bearer[], result: PayResult): NwcChangeset => {
-  bearers: Bearer[],
-  result: PayResult
-): NwcChangeset => {
   const add: NewBearer[] = []
-  const markSpent: string[] = result.carve.consumed.map(b => b.id)
+  const markSpent: string[] = result.carve.consumed.map((b) => b.id)
   if (result.carve.change) add.push(result.carve.change)
   if (result.outcome === 'failed-funds-returned') {
     add.push(result.carve.note)
@@ -44,9 +41,7 @@ export const payChangeset = (
     // carve), lock that bearer; a freshly carved note is never added -
     // it was born spent
     const carvedK1 = noteK1(result.carve.note.url)
-    const existing = carvedK1
+    const existing = carvedK1 ? bearers.find((b) => noteK1(b.url) === carvedK1) : undefined
-      ? bearers.find(b => noteK1(b.url) === carvedK1)
-      : undefined
     if (existing) markSpent.push(existing.id)
   }
   if (result.rescuedNote) add.push(result.rescuedNote)
@@ -55,10 +50,9 @@ export const payChangeset = (
 
 export const handlePayInvoice = async (
   ctx: RequestContext,
-  params: Record<string, unknown>
+  params: Record<string, unknown>,
 ): Promise<NwcResponse> => {
-  const invoice =
+  const invoice = typeof params.invoice === 'string' ? params.invoice.trim() : ''
-    typeof params.invoice === 'string' ? params.invoice.trim() : ''
   if (!isBolt11Invoice(invoice)) {
     return errResult('pay_invoice', 'OTHER', 'Missing or invalid bolt11 invoice.')
   }
@@ -69,23 +63,17 @@ export const handlePayInvoice = async (
     return errResult(
       'pay_invoice',
       'OTHER',
-      'Could not read this invoice\'s amount - amount-less invoices are not supported.'
+      "Could not read this invoice's amount - amount-less invoices are not supported.",
     )
   }
   if (params.amount !== undefined && params.amount !== amountMsat) {
-    return errResult(
+    return errResult('pay_invoice', 'OTHER', "The request's amount does not match the invoice.")
-      'pay_invoice',
-      'OTHER',
-      'The request\'s amount does not match the invoice.'
-    )
   }
-  if (
+  if (amountMsat > budgetRemainingMsat(ctx.connection().record, Date.now())) {
-    amountMsat > budgetRemainingMsat(ctx.connection().record, Date.now())
-  ) {
     return errResult(
       'pay_invoice',
       'QUOTA_EXCEEDED',
-      'This payment exceeds the connection\'s budget.'
+      "This payment exceeds the connection's budget.",
     )
   }
   const bearers = ctx.deps.getBearers()
@@ -93,77 +81,100 @@ export const handlePayInvoice = async (
   try {
     result = await payWithBearers(bearers, invoice, {
       poll: ctx.deps.poll ?? {},
-      kit: ctx.deps.kit ?? {}
+      kit: ctx.deps.kit ?? {},
+      assertOwner: ctx.assertOwner,
     })
   } catch (err) {
     if (err instanceof UncertainOutcomeError) {
       // the carve's answer was lost and the probe couldn't tell: the
       // possible outputs carry fresh secrets that may be the only money
       // left - tracked unverified, never dropped
-      ctx.deps.applyChangeset(
+      await ctx.deps.applyChangeset(
         {add: err.possibleOutputs, markSpent: []},
         ctx.connection(),
-        'pay_invoice'
+        'pay_invoice',
+        ctx.assertOwner,
       )
       return errResult(
         'pay_invoice',
         'INTERNAL',
-        'The payment preparation could not be confirmed; possible new notes were stored unverified.'
+        'The payment preparation could not be confirmed; possible new notes were stored unverified.',
       )
     }
     const message = err instanceof Error ? err.message : String(err)
     return errResult(
       'pay_invoice',
       /enough/i.test(message) ? 'INSUFFICIENT_BALANCE' : 'INTERNAL',
-      message
+      message,
     )
   }
   const spendRecorded = (): void => {
-    ctx.updateRecord(recordSpend(ctx.connection().record, amountMsat, Date.now()))
+    // This conservative budget debit is persisted separately from bearer
+    // storage. A later bearer commit failure does not roll it back.
+    const connection = ctx.connection().record
+    ctx.updateRecord(recordSpend(connection.ownerId, connection, amountMsat, Date.now()))
   }
   switch (result.outcome) {
     case 'settled': {
       spendRecorded()
-      ctx.deps.applyChangeset(payChangeset(bearers, result), ctx.connection(), 'pay_invoice')
+      await ctx.deps.applyChangeset(
+        payChangeset(bearers, result),
+        ctx.connection(),
+        'pay_invoice',
+        ctx.assertOwner,
+      )
       // the receipt NIP-47 clients expect: the melt's own payment
       // preimage, re-read from the settle proof. A mint that reveals
       // none yields an empty preimage rather than a fabricated one.
       let preimage = ''
       if (result.verifyUrl) {
         try {
-          const proof = await fetchInvoiceVerification(
+          const proof = await fetchInvoiceVerification(result.verifyUrl, ctx.deps.kit ?? {})
-            result.verifyUrl,
-            ctx.deps.kit ?? {}
-          )
           preimage = proof.preimage ?? ''
-        } catch {
+        } catch (error) {
           // the settle proof was already polled inside payWithBearers;
           // a failed re-read must not flip the outcome
+          if (!(error instanceof Error)) throw error
         }
       }
       return okResult('pay_invoice', {preimage})
     }
     case 'failed-funds-returned':
-      ctx.deps.applyChangeset(payChangeset(bearers, result), ctx.connection(), 'pay_invoice')
+      await ctx.deps.applyChangeset(
+        payChangeset(bearers, result),
+        ctx.connection(),
+        'pay_invoice',
+        ctx.assertOwner,
+      )
       return errResult(
         'pay_invoice',
         'PAYMENT_FAILED',
-        'The payment failed; the funds are back in the wallet.'
+        'The payment failed; the funds are back in the wallet.',
       )
     case 'note-already-spent':
-      ctx.deps.applyChangeset(payChangeset(bearers, result), ctx.connection(), 'pay_invoice')
+      await ctx.deps.applyChangeset(
+        payChangeset(bearers, result),
+        ctx.connection(),
+        'pay_invoice',
+        ctx.assertOwner,
+      )
       return errResult(
         'pay_invoice',
         'PAYMENT_FAILED',
-        'The note backing this payment was already spent; nothing was paid.'
+        'The note backing this payment was already spent; nothing was paid.',
       )
     case 'unknown-still-pending':
       spendRecorded()
-      ctx.deps.applyChangeset(payChangeset(bearers, result), ctx.connection(), 'pay_invoice')
+      await ctx.deps.applyChangeset(
+        payChangeset(bearers, result),
+        ctx.connection(),
+        'pay_invoice',
+        ctx.assertOwner,
+      )
       return errResult(
         'pay_invoice',
         'OTHER',
-        'The payment is still in flight; the note stays locked until it reconciles.'
+        'The payment is still in flight; the note stays locked until it reconciles.',
       )
   }
 }