From 46829a7a54bf21138d8bb068966f7f083ac8df4c Mon Sep 17 00:00:00 2001 From: Adam Soltys Date: Thu, 15 Oct 2026 15:13:12 -0700 Subject: Lightning login (LNURL-auth): a site's login lnurl in Send logs you in instead of trying to pay it. A community member pasted Stacker News's lightning-login lnurl into Send and got "stacker.news: no sig query variable provided" (2026-10-16): every lnurl1 was taken for LNURL-pay, their login endpoint was fetched as if for pay parameters, and its refusal came back as the error. Now an lnurl whose URL carries tag=login and a 32-byte k1 (parseLnurlAuth; lightning: prefix and upper case fine; action register|login|link|auth) is a login: the wallet asks first — the site's name, what it is asking (log in / create an account / link / confirm it's you), that the challenge is signed with a key kept for this site alone and that nothing is paid or shared — then signs k1 (ECDSA, DER) with the LUD-05 linking key (m/138'/0 as hashing key, HMAC-SHA256 of the domain read as four 32-bit child indexes under m/138'; the same wallet is the same user on a site every time and a different one elsewhere; from the mnemonic, or an imported xprv) and calls back with sig and key (lnurlAuthKey, lnurlAuthLogin). The site's OK shows "Logged in to ", its reason otherwise, with Try again and Back. It takes no balance (checked before canPay in zaps' matchSendText), so it works on an empty wallet and from an Android lightning: intent. tools/lnurl-auth-unit-test.js (login vs pay vs bad k1; one key per site per wallet; the DER signature verifies under the key sent; the server's reason is the error) and tools/lnurl-auth-test.js (a stand-in site that verifies the signature: the ask, nothing sent before Log in, OK, the same key next time, a register link, a refusal's words); send-dest-test passes. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Co-Authored-By: Claude Fable 5.1 Claude-Session: https://claude.ai/code/session_01J1Kon8bxJoHRpJdSzshCkp --- src/features/zaps.js | 69 +++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 66 insertions(+), 3 deletions(-) (limited to 'src/features') diff --git a/src/features/zaps.js b/src/features/zaps.js index d327f9d..f29fe83 100644 --- a/src/features/zaps.js +++ b/src/features/zaps.js @@ -13,7 +13,9 @@ import { t } from '../i18n.js'; import { npubOf } from '../nostr.js'; -import { parseZapTarget, zapTargetFromProfile, fetchPayParams, buildZapRequest, requestInvoice } from '../lnurl.js'; +import { parseZapTarget, zapTargetFromProfile, fetchPayParams, buildZapRequest, requestInvoice, parseLnurlAuth, lnurlAuthKey, lnurlAuthLogin } from '../lnurl.js'; +import { HDKey } from '@scure/bip32'; +import { mnemonicToSeedSync } from '@scure/bip39'; import { decodeNoffer } from '../noffer.js'; import { requestOfferInvoice } from '../clink.js'; import { decodeOffer } from '../bolt12.js'; @@ -290,6 +292,64 @@ export function zapsFeature(ctx) { } } + // ---- Lightning login (LNURL-auth) ---- + // A site's login lnurl pasted (or tapped) into Send: not a payment but a + // challenge to sign. Ask first — it is an identity act, naming the site — + // then sign with the key this wallet keeps for that site alone (LUD-05) + // and tell the site. (Adam, 2026-10-16: a Stacker News login lnurl in Send + // got "no sig query variable provided" — it was being paid.) + function beginLogin(auth) { + ui.zap = null; ui.sendError = ''; + ui.lnAuth = { auth, status: 'ask' }; + render(); + } + const masterKey = () => { + if (wallet.mnemonic) return HDKey.fromMasterSeed(mnemonicToSeedSync(wallet.mnemonic, wallet.passphrase || '')); + if (wallet.xprv) return HDKey.fromExtendedKey(wallet.xprv); + return null; + }; + async function doLogin(a) { + a.status = 'busy'; render(); + try { + const master = masterKey(); + if (!master) throw new Error(t('lnAuthNoKey')); + await lnurlAuthLogin(a.auth, lnurlAuthKey(master, a.auth.domain)); + if (ui.lnAuth !== a) return; + a.status = 'done'; + } catch (e) { + if (ui.lnAuth !== a) return; + a.status = 'error'; a.error = e.message || String(e); + } + render(); + } + function lnAuthView() { + const a = ui.lnAuth; + if (!a) return null; + const { domain, action } = a.auth; + const back = () => { ui.lnAuth = null; ui.sendError = ''; ui.send = blankSend(); render(); }; + const heading = '🔑 ' + t('lnAuthTitle'); + if (a.status === 'busy') { + return h('div', { class: 'card col', style: 'align-items:center;gap:14px;padding:32px 14px' }, + h('span', { class: 'spinner' }), + h('p', { class: 'muted', style: 'margin:0' }, t('lnAuthSigning', { domain }))); + } + if (a.status === 'done') { + return h('div', { class: 'card col', style: 'align-items:center;text-align:center;gap:14px;padding:32px 14px' }, + h('div', { class: 'check-badge' }, '✓'), + h('h3', { style: 'margin:0' }, t('lnAuthDoneTitle', { domain })), + h('p', { class: 'small muted', style: 'margin:0' }, t('lnAuthDoneHint')), + h('button', { class: 'btn-primary btn-block', onClick: back }, t('done'))); + } + const ask = t(action === 'register' ? 'lnAuthAskRegister' : action === 'link' ? 'lnAuthAskLink' : action === 'auth' ? 'lnAuthAskAuth' : 'lnAuthAskLogin', { domain }); + return h('div', { class: 'card col', style: 'gap:12px' }, + h('h3', {}, heading), + h('div', { class: 'small', style: 'font-size:18px;font-weight:600;word-break:break-all' }, domain), + h('p', { class: 'small muted', style: 'margin:0' }, ask), + h('p', { class: 'small muted', style: 'margin:0' }, t('lnAuthHow')), + a.status === 'error' ? h('div', { class: 'notice err' }, a.error || t('lnAuthFailed')) : null, + h('button', { class: 'btn-primary btn-block', onClick: () => doLogin(a) }, a.status === 'error' ? t('lnAuthRetry') : t(action === 'register' ? 'lnAuthGoRegister' : 'lnAuthGo')), + h('button', { class: 'btn-ghost btn-block', onClick: back }, t('back'))); + } function zapView() { const z = ui.zap; if (!z) return null; @@ -391,6 +451,9 @@ export function zapsFeature(ctx) { id: 'zaps', // A lightning address / lnurl (always), or an npub that Ark didn't claim. matchSendText(text, typed) { + // a login challenge needs no balance, only the wallet's key + const auth = parseLnurlAuth(text); + if (auth) { beginLogin(auth); return true; } if (!canPay() || !ui.send || ui.send.recipients.length !== 1) return false; const tap = !typed; // scanned/pasted (a tap), not a keystroke const nof = maybeNoffer(text); @@ -472,8 +535,8 @@ export function zapsFeature(ctx) { begin({ kind: 'npub', pk, eventId: eventId || null }, shortNpub(npub || npubOf(pk))); return true; }, - resetSend() { ui.zap = null; }, - sendView() { return zapView(); }, + resetSend() { ui.zap = null; ui.lnAuth = null; }, + sendView() { return lnAuthView() || zapView(); }, // Settings → Nostr: the one-tap zap amount. nostrSettingsCards() { const cur = ctx.zapDefaultSat ? ctx.zapDefaultSat() : 0; -- cgit v1.2.3