fix(security): audit remediation 2026-09-01: api_keys identity, viewer gates, OAuth binding, XSS, MFA gate (#2155)

* fix(security): bind api_keys to the caller, lock hash-as-bearer RPCs and provider token tables Security audit 2026-09-01, critical items. - api_keys INSERT requires user_id = auth.uid() again (an admin could forge a key for any co-member and act as them in every company they belong to); SELECT is own-keys-or-admin; a BEFORE trigger freezes the identity and credential columns against user-session UPDATEs. - rotate_mcp_refresh_token and validate_and_increment_api_key become service_role only: they match rows by a presented SHA-256, so a hash readable by co-members was a bearer credential. - validate_and_increment_api_key fails closed when the key's user is no longer a member of the key's company. - provider_consent_tokens and provider_otc: the DELETE policies collapsed to "caller has any team row" (correlated subquery on a non-existent team_members.company_id). All member policies dropped; service_role only, matching every existing code path. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(security): role gates, ownership guards and posting integrity in the database Security audit 2026-09-01, high items at the database layer. - One table-level guard, enforce_company_writer_role(), blocks the read-only viewer role on 55 company-scoped tables including through the 15 membership-only SECURITY DEFINER writers. Keyed on the JWT role claim so it fires inside definer bodies; no-op for service_role and trigger cascades. - company_members user_id/company_id immutable from user sessions; invitations can never grant owner; team_members gains a transition guard (admins keep non-owner role moves); companies team_id and archiving are owner-only and team attachment needs team membership. - Direct statements (current_user = authenticated) can no longer insert posted headers, add lines under posted verifikat, or post a draft with a voucher number the sequence never issued. Sanctioned RPCs run as the definer and are untouched; the engine's own draft-then-post shapes still pass. - create_document_version refuses viewers and foreign storage paths; validate_version_chain needs membership and loses anon EXECUTE; match_documents / match_booking_templates lose anon; cron maintenance RPCs become service_role only; the production-only seed_asset_categories is dropped. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * build: pin tsx as an exact devDependency instead of fetching it with npx at build time prebuild ran "npx tsx" with no lockfile entry, so every Vercel, Docker and CI build downloaded tsx@latest and its transitive tree from the registry with no integrity check, inside the build environment. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(security): refuse the viewer role on API-key and MCP write paths The v1 wrapper and the MCP company routing checked company membership but never role, and both run as service role, so a read-only viewer holding an API key could post vouchers and change settings through the API. Mutating methods and non-read scopes now return 403 ROLE_READ_ONLY for viewers on v1; MCP write tools refuse viewers the same way. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(security): stop serving uploaded SVG, XML and HTML as executable content on the app origin Uploads persisted the browser-declared mime type and the inline proxy served it verbatim, sandboxing only text/html; the storage proxy forwarded the uploader's Content-Type. Any writer, or any Peppol sender, could plant a scripted SVG or XHTML that executed on app.gnubok.se. - inline route: allow-list of natively safe types (PDF, raster images) served as before; everything else gets the opaque sandbox CSP. - storage proxy: octet-stream + attachment + sandbox unless the DB mime for the key is on the allow-list. - document-service: the stored mime is the magic-byte validated type. - logo upload: magic-byte validation, SVG refused. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(security): byrå brand logo upload decides the type by magic bytes and drops SVG Same pattern as the company logo route: the logos bucket is public, so a scripted SVG (or anything declared as an image) must never land there. The upload pickers stop advertising SVG. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(security): bind Enable Banking, Stripe and WooCommerce callbacks to the initiating user The callbacks resolved the pending row by oauth_state alone, so a victim who completed an attacker-initiated consent had their bank account, merchant account or store attached to the attacker's company. requireFlowInitiator() now requires the cookie session of the user who started the flow: no session redirects to login with the callback URL preserved, a different user is refused and nothing is exchanged. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(security): guard tenant-controlled outbound fetches and surface the disabled rate limiter WooCommerce and Shopify syncs fetched a member-editable store URL with plain fetch() and redirect following under the service role, and the invoice PDF renderer fetched company_settings.logo_url unguarded. All three go through a new safeFetch() (public-IP validation via url-guard, https only, redirect: 'manual', body size cap) and re-normalise the stored host at use time. checkRateLimit() keeps failing open on hosted but logs one error per process when Upstash is not configured and exports isRateLimiterConfigured(). Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(security): decide the API MFA gate from server-authenticated factors, not the session cookie getAuthenticatorAssuranceLevel() without arguments derives nextLevel from session.user.factors, which comes from the unsigned sb-*-auth-token cookie. Deleting factors from the cookie made an enrolled account look like it had nothing to step up to, on every /api route and in requireAuth. Both gates now read factors from the getUser() result or listFactors() and the level from the verified JWT claim, and fail closed on errors. Page-branch gate hardened the same way. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(security): bind Fortnox/Visma, Gmail and Skatteverket callbacks to the initiating user The arcim-migration callback exchanged the provider code onto whatever consent the one-time state named, with no check of who completed the flow and no org-number comparison, so a phished Fortnox admin handed their ledger to the attacker's company. provider_otc now records the initiating user (migration 20260902100000); the callback requires that session and, after the exchange, refuses a provider company whose org number differs from the consent's company. The Gmail and Skatteverket callbacks enforce the same initiator check. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(security): BankID signup confirms the email before linking the identity Signup created an email-confirmed, MFA-exempt account for any address the caller typed and returned a magic link, so an attacker could pre-register a victim's email and keep a permanent BankID login into the account the victim later adopted. The user is now created unconfirmed, the identity carries email_verified_at NULL (migration 20260902101000), bankid_linked is not set until the mailed confirmation is clicked, and BankID login of a pending identity is refused with the confirmation re-sent. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(security): bind MCP OAuth redirect URIs to the consenting user and cap scopes A user-registered redirect URI was allowlisted globally, the consent page named no client, and all scopes were pre-checked, so one phishing link handed an attacker a full-scope key for the victim's company. Registered URIs now resolve only for the registrant or a colleague sharing a company; the consent page shows the client identity and redirect host; non-built-in clients default to read-only pre-checks; scopes are capped by the user's role (viewer: read only) at consent and at /token. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(auth): client follow-ups for BankID confirmation, callback mismatch copy and decision log - register client handles the new confirmation_sent response from BankID signup with the existing inbox screen instead of calling verifyOtp. - BankID login surfaces the email_unconfirmed explanation. - WooCommerce settings map woocommerce_error=wrong_user to its own copy. - Logo help text no longer advertises SVG. - DECISIONS.md records the audit remediation choices. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(mcp-oauth): literal SoD columns in the api_keys insert so the phantom-column scanner resolves them Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * test(logo): type the upload fixtures as Uint8Array<ArrayBuffer> so they are valid BlobParts Fixes the typecheck ratchet on PR #2155 and ratchets the baseline down by the one legacy error the change removed. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> --------- Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com> Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>
2026-09-02 11:38:30 +02:00
parent 6e8d76a9cb
commit 18cbc4c30a
92 changed files with 10355 additions and 657 deletions
@@ -1,5 +1,13 @@
-import { describe, it, expect, vi } from 'vitest'
-import { isBuiltInRedirectUri, isAllowedRedirectUri } from '../oauth-allowlist'
+import { describe, it, expect, vi, afterEach } from 'vitest'
+import {
+  builtInRedirectProvider,
+  capScopesForRole,
+  isAllowedRedirectUri,
+  isBuiltInRedirectUri,
+  lookupCompanyRole,
+  resolveRedirectUri,
+} from '../oauth-allowlist'
+import { ALL_SCOPES, type ApiKeyScope } from '../scope-catalog'
 import type { SupabaseClient } from '@supabase/supabase-js'

 describe('isBuiltInRedirectUri', () => {
@@ -23,45 +31,244 @@ describe('isBuiltInRedirectUri', () => {
  })
 })

-function makeFakeSupabase(rows: Array<{ id: string }>): SupabaseClient {
-  // Chainable thenable that resolves to { data, error } when awaited via
-  // .maybeSingle(). Matches the shape isAllowedRedirectUri actually invokes.
-  const chain = {
-    from() { return chain },
-    select() { return chain },
-    eq() { return chain },
-    is() { return chain },
-    limit() { return chain },
-    async maybeSingle() {
-      return { data: rows[0] ?? null, error: null }
-    },
-  }
-  return chain as unknown as SupabaseClient
+describe('builtInRedirectProvider', () => {
+  it.each([
+    ['https://claude.ai/api/oauth/callback', 'claude'],
+    ['https://claude.com/api/oauth/callback', 'claude'],
+    ['https://chatgpt.com/connector/oauth/abc123', 'chatgpt'],
+    ['https://chatgpt.com/connector_platform_oauth_redirect', 'chatgpt'],
+    ['http://localhost:3000/cb', 'local'],
+    ['http://127.0.0.1:8080/cb', 'local'],
+    ['https://claude-login.example/cb', null],
+    ['', null],
+  ])('maps %s to %s', (uri, expected) => {
+    expect(builtInRedirectProvider(uri)).toBe(expected)
+  })
+})
+
+type Row = Record<string, unknown>
+
+/**
+ * Minimal PostgREST-shaped fake over in-memory tables: eq/is filters are
+ * applied, everything else is a no-op, and the chain resolves to the filtered
+ * rows (all rows when awaited, first row via maybeSingle). `failTable` makes
+ * every query against that table return a DB error.
+ */
+function fakeClient(tables: Record<string, Row[]>, failTable?: string) {
+  const from = vi.fn((table: string) => {
+    const filters: [string, unknown][] = []
+    const run = () =>
+      (tables[table] ?? []).filter((row) =>
+        filters.every(([col, val]) => (val === null ? row[col] == null : row[col] === val)),
+      )
+    const result = () =>
+      table === failTable
+        ? { data: null, error: { message: 'db down' } }
+        : { data: run(), error: null }
+    const chain: Record<string, unknown> = {}
+    for (const method of ['select', 'order', 'range', 'limit']) chain[method] = () => chain
+    chain.eq = (col: string, val: unknown) => {
+      filters.push([col, val])
+      return chain
+    }
+    chain.is = (col: string, val: unknown) => {
+      filters.push([col, val])
+      return chain
+    }
+    chain.maybeSingle = async () => {
+      const r = result()
+      return { data: Array.isArray(r.data) ? (r.data[0] ?? null) : null, error: r.error }
+    }
+    chain.then = (resolve: (v: unknown) => void) => resolve(result())
+    return chain
+  })
+  return { from } as unknown as SupabaseClient & { from: ReturnType<typeof vi.fn> }
 }

-describe('isAllowedRedirectUri', () => {
-  it('short-circuits to true for built-in patterns without touching the DB', async () => {
+const REGISTRATIONS: Row[] = [
+  { id: 'reg-1', user_id: 'user-2', client_name: 'Byråns bot', redirect_uri: 'https://app.example.com/cb', revoked_at: null },
+  { id: 'reg-2', user_id: 'user-9', client_name: 'Evil', redirect_uri: 'https://evil.example/cb', revoked_at: null },
+  { id: 'reg-3', user_id: 'user-1', client_name: 'Min egen app', redirect_uri: 'https://mine.example/cb', revoked_at: null },
+  { id: 'reg-4', user_id: 'user-1', client_name: 'Gammal app', redirect_uri: 'https://old.example/cb', revoked_at: '2026-01-01T00:00:00Z' },
+]
+
+const MEMBERSHIPS: Row[] = [
+  { id: 'm1', user_id: 'user-1', company_id: 'company-1', role: 'owner' },
+  { id: 'm2', user_id: 'user-2', company_id: 'company-1', role: 'member' },
+  { id: 'm3', user_id: 'user-2', company_id: 'company-2', role: 'owner' },
+  { id: 'm4', user_id: 'user-9', company_id: 'company-9', role: 'owner' },
+]
+
+const DB = { oauth_client_registrations: REGISTRATIONS, company_members: MEMBERSHIPS }
+
+describe('resolveRedirectUri', () => {
+  afterEach(() => {
+    vi.unstubAllEnvs()
+  })
+
+  it('short-circuits to the built-in provider without touching the DB', async () => {
    const sb = {
      from: vi.fn(() => {
        throw new Error('should not be called')
      }),
    } as unknown as SupabaseClient
-    expect(await isAllowedRedirectUri('https://claude.ai/api/cb', sb)).toBe(true)
-    expect(await isAllowedRedirectUri('http://localhost:3000/cb', sb)).toBe(true)
+    expect(await resolveRedirectUri('https://claude.ai/api/cb', sb, { consentingUserId: 'user-1' })).toEqual({
+      allowed: true,
+      kind: 'built_in',
+      provider: 'claude',
+    })
+    expect(await resolveRedirectUri('http://localhost:3000/cb', sb)).toEqual({
+      allowed: true,
+      kind: 'built_in',
+      provider: 'local',
+    })
  })

-  it('returns true when the DB has a registration for the URI', async () => {
-    const sb = makeFakeSupabase([{ id: 'reg-1' }])
-    expect(await isAllowedRedirectUri('https://myapp.example.com/cb', sb)).toBe(true)
+  it("accepts the consenting user's own registration", async () => {
+    const result = await resolveRedirectUri('https://mine.example/cb', fakeClient(DB), {
+      consentingUserId: 'user-1',
+    })
+    expect(result).toEqual({
+      allowed: true,
+      kind: 'registered',
+      clientName: 'Min egen app',
+      registeredByConsentingUser: true,
+    })
  })

-  it('returns false when no registration exists', async () => {
-    const sb = makeFakeSupabase([])
-    expect(await isAllowedRedirectUri('https://evil.com/cb', sb)).toBe(false)
+  it('accepts a registration by a colleague who shares a company', async () => {
+    const result = await resolveRedirectUri('https://app.example.com/cb', fakeClient(DB), {
+      consentingUserId: 'user-1',
+    })
+    expect(result).toEqual({
+      allowed: true,
+      kind: 'registered',
+      clientName: 'Byråns bot',
+      registeredByConsentingUser: false,
+    })
  })

-  it('returns false for empty / non-string inputs', async () => {
-    expect(await isAllowedRedirectUri('')).toBe(false)
-    expect(await isAllowedRedirectUri(undefined as unknown as string)).toBe(false)
+  it('rejects a registration by an unrelated user', async () => {
+    // user-9 is a real member of the instance, just not of any company user-1
+    // belongs to: their registration must not be a valid target for user-1.
+    const result = await resolveRedirectUri('https://evil.example/cb', fakeClient(DB), {
+      consentingUserId: 'user-1',
+    })
+    expect(result).toEqual({ allowed: false })
+  })
+
+  it('accepts any active registration when no consenting user is given (anonymous /register)', async () => {
+    const result = await resolveRedirectUri('https://evil.example/cb', fakeClient(DB))
+    expect(result).toEqual({
+      allowed: true,
+      kind: 'registered',
+      clientName: 'Evil',
+      registeredByConsentingUser: false,
+    })
+  })
+
+  it('rejects a revoked registration, even the user’s own', async () => {
+    const result = await resolveRedirectUri('https://old.example/cb', fakeClient(DB), {
+      consentingUserId: 'user-1',
+    })
+    expect(result).toEqual({ allowed: false })
+  })
+
+  it('rejects an unknown URI', async () => {
+    expect(await resolveRedirectUri('https://nowhere.example/cb', fakeClient(DB))).toEqual({ allowed: false })
+  })
+
+  it('fails closed when the registration lookup errors', async () => {
+    const result = await resolveRedirectUri(
+      'https://mine.example/cb',
+      fakeClient(DB, 'oauth_client_registrations'),
+      { consentingUserId: 'user-1' },
+    )
+    expect(result).toEqual({ allowed: false })
+  })
+
+  it('fails closed when the shared-company check errors', async () => {
+    const result = await resolveRedirectUri('https://app.example.com/cb', fakeClient(DB, 'company_members'), {
+      consentingUserId: 'user-1',
+    })
+    expect(result).toEqual({ allowed: false })
+  })
+
+  it('fails closed when no client is given and none can be constructed', async () => {
+    vi.stubEnv('NEXT_PUBLIC_SUPABASE_URL', '')
+    vi.stubEnv('SUPABASE_SERVICE_ROLE_KEY', '')
+    expect(await resolveRedirectUri('https://mine.example/cb', undefined, { consentingUserId: 'user-1' })).toEqual({
+      allowed: false,
+    })
+  })
+
+  it('returns not allowed for empty / non-string inputs', async () => {
+    expect(await resolveRedirectUri('')).toEqual({ allowed: false })
+    expect(await resolveRedirectUri(undefined as unknown as string)).toEqual({ allowed: false })
+  })
+})
+
+describe('isAllowedRedirectUri', () => {
+  it('is the boolean view of resolveRedirectUri', async () => {
+    expect(await isAllowedRedirectUri('https://claude.ai/api/cb')).toBe(true)
+    expect(await isAllowedRedirectUri('https://mine.example/cb', fakeClient(DB), { consentingUserId: 'user-1' })).toBe(true)
+    expect(await isAllowedRedirectUri('https://evil.example/cb', fakeClient(DB), { consentingUserId: 'user-1' })).toBe(false)
+    expect(await isAllowedRedirectUri('https://evil.example/cb', fakeClient(DB))).toBe(true)
+    expect(await isAllowedRedirectUri('', fakeClient(DB))).toBe(false)
+  })
+})
+
+describe('capScopesForRole', () => {
+  const mixed: ApiKeyScope[] = [
+    'transactions:read',
+    'transactions:write',
+    'pending_operations:approve',
+    'webhooks:manage',
+    'reconciliation:signoff',
+    'reports:read',
+  ]
+
+  it('keeps every scope for owner, admin and member', () => {
+    for (const role of ['owner', 'admin', 'member']) {
+      expect(capScopesForRole(mixed, role)).toEqual(mixed)
+    }
+  })
+
+  it('caps a viewer to :read scopes only', () => {
+    expect(capScopesForRole(mixed, 'viewer')).toEqual(['transactions:read', 'reports:read'])
+  })
+
+  it('caps an unknown role and a missing membership to :read scopes', () => {
+    expect(capScopesForRole(mixed, 'superuser')).toEqual(['transactions:read', 'reports:read'])
+    expect(capScopesForRole(mixed, null)).toEqual(['transactions:read', 'reports:read'])
+  })
+
+  it('leaves no write-kind scope in a capped set for the full catalogue', () => {
+    const capped = capScopesForRole(ALL_SCOPES, 'viewer')
+    expect(capped.length).toBeGreaterThan(0)
+    expect(capped.every((s) => s.endsWith(':read'))).toBe(true)
+    expect(capped).not.toContain('pending_operations:approve')
+  })
+
+  it('returns a copy, never the caller’s array', () => {
+    const result = capScopesForRole(mixed, 'owner')
+    expect(result).not.toBe(mixed)
+  })
+})
+
+describe('lookupCompanyRole', () => {
+  it('returns the role for an existing membership', async () => {
+    expect(await lookupCompanyRole(fakeClient(DB), 'user-2', 'company-1')).toEqual({ role: 'member', error: null })
+    expect(await lookupCompanyRole(fakeClient(DB), 'user-2', 'company-2')).toEqual({ role: 'owner', error: null })
+  })
+
+  it('returns a null role when no membership row exists', async () => {
+    expect(await lookupCompanyRole(fakeClient(DB), 'user-9', 'company-1')).toEqual({ role: null, error: null })
+  })
+
+  it('surfaces a query error instead of guessing', async () => {
+    const result = await lookupCompanyRole(fakeClient(DB, 'company_members'), 'user-1', 'company-1')
+    expect(result.role).toBeNull()
+    expect(result.error).toBe('db down')
  })
 })
@@ -0,0 +1,148 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest'
+
+vi.mock('@/lib/supabase/server', () => ({
+  createClient: vi.fn(),
+}))
+
+import { createClient } from '@/lib/supabase/server'
+import {
+  requireFlowInitiator,
+  buildLoginRedirect,
+  redactUserId,
+  FLOW_INITIATOR_MISMATCH_MESSAGE,
+} from '../oauth-flow-binding'
+
+const CALLBACK_URL =
+  'https://app.example.se/api/extensions/stripe/callback?code=ac_123&state=state-1'
+
+function mockSession(getUser: ReturnType<typeof vi.fn>) {
+  vi.mocked(createClient).mockResolvedValue({ auth: { getUser } } as never)
+  return getUser
+}
+
+function sessionWith(userId: string | null, error: unknown = null) {
+  return mockSession(
+    vi.fn().mockResolvedValue({
+      data: { user: userId ? { id: userId } : null },
+      error,
+    }),
+  )
+}
+
+describe('requireFlowInitiator', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    vi.stubEnv('NEXT_PUBLIC_APP_URL', 'https://app.example.se')
+  })
+
+  afterEach(() => {
+    vi.unstubAllEnvs()
+  })
+
+  it('passes when the cookie session belongs to the initiator', async () => {
+    const getUser = sessionWith('user-1')
+
+    const result = await requireFlowInitiator(new Request(CALLBACK_URL), 'user-1')
+
+    expect(result).toEqual({ ok: true, userId: 'user-1' })
+    expect(getUser).toHaveBeenCalledTimes(1)
+  })
+
+  it('refuses with a 403 envelope when a different user completes the flow', async () => {
+    sessionWith('user-2')
+
+    const result = await requireFlowInitiator(new Request(CALLBACK_URL), 'user-1', {
+      flow: 'stripe.callback',
+    })
+
+    expect(result.ok).toBe(false)
+    if (result.ok) throw new Error('unreachable')
+    expect(result.reason).toBe('mismatch')
+    if (result.reason !== 'mismatch') throw new Error('unreachable')
+    expect(result.sessionUserId).toBe('user-2')
+    expect(result.response.status).toBe(403)
+    const body = await result.response.json()
+    expect(body.error.code).toBe('OAUTH_FLOW_INITIATOR_MISMATCH')
+    expect(body.error.message).toBe(FLOW_INITIATOR_MISMATCH_MESSAGE)
+    expect(typeof body.error.message_en).toBe('string')
+  })
+
+  it('sends an anonymous browser to /login with the callback URL as next', async () => {
+    sessionWith(null)
+
+    const result = await requireFlowInitiator(new Request(CALLBACK_URL), 'user-1')
+
+    expect(result.ok).toBe(false)
+    if (result.ok) throw new Error('unreachable')
+    expect(result.reason).toBe('no_session')
+    expect(result.response.status).toBe(307)
+    const location = new URL(result.response.headers.get('location') ?? '')
+    expect(location.origin).toBe('https://app.example.se')
+    expect(location.pathname).toBe('/login')
+    // Same-origin relative path + query, the only shape the login page's
+    // safeReturnTo accepts, so signing in resumes the very same callback.
+    expect(location.searchParams.get('next')).toBe(
+      '/api/extensions/stripe/callback?code=ac_123&state=state-1',
+    )
+  })
+
+  it('treats a getUser error as no session (fail closed)', async () => {
+    sessionWith(null, { message: 'invalid JWT' })
+
+    const result = await requireFlowInitiator(new Request(CALLBACK_URL), 'user-1')
+
+    expect(result.ok).toBe(false)
+    if (result.ok) throw new Error('unreachable')
+    expect(result.reason).toBe('no_session')
+  })
+
+  it('treats a thrown client error as no session instead of finalizing on a guess', async () => {
+    vi.mocked(createClient).mockRejectedValue(new Error('cookies() outside request scope'))
+
+    const result = await requireFlowInitiator(new Request(CALLBACK_URL), 'user-1')
+
+    expect(result.ok).toBe(false)
+    if (result.ok) throw new Error('unreachable')
+    expect(result.reason).toBe('no_session')
+    expect(result.response.headers.get('location')).toContain('/login?next=')
+  })
+
+  it('never passes on an empty expected id even when someone is signed in', async () => {
+    sessionWith('user-2')
+
+    const result = await requireFlowInitiator(new Request(CALLBACK_URL), '')
+
+    expect(result.ok).toBe(false)
+  })
+})
+
+describe('buildLoginRedirect', () => {
+  afterEach(() => {
+    vi.unstubAllEnvs()
+  })
+
+  it('falls back to the request origin when NEXT_PUBLIC_APP_URL is unset', () => {
+    vi.stubEnv('NEXT_PUBLIC_APP_URL', '')
+
+    const response = buildLoginRedirect(
+      new Request('http://localhost:3000/api/extensions/woocommerce/return?success=1&user_id=abc'),
+    )
+
+    expect(response.headers.get('location')).toBe(
+      'http://localhost:3000/login?next=' +
+        encodeURIComponent('/api/extensions/woocommerce/return?success=1&user_id=abc'),
+    )
+  })
+})
+
+describe('redactUserId', () => {
+  it('keeps only a correlation prefix of a uuid', () => {
+    expect(redactUserId('123e4567-e89b-12d3-a456-426614174000')).toBe('123e4567...')
+  })
+
+  it('handles short and missing ids', () => {
+    expect(redactUserId('user-1')).toBe('user-1')
+    expect(redactUserId(null)).toBe('(none)')
+    expect(redactUserId(undefined)).toBe('(none)')
+  })
+})
@@ -0,0 +1,155 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+
+const mocks = vi.hoisted(() => ({
+  logError: vi.fn(),
+  logWarn: vi.fn(),
+  logInfo: vi.fn(),
+  redisCtor: vi.fn(),
+  ratelimitCtor: vi.fn(),
+  limit: vi.fn(),
+}))
+
+vi.mock('@/lib/logger', () => ({
+  createLogger: () => ({
+    error: mocks.logError,
+    warn: mocks.logWarn,
+    info: mocks.logInfo,
+    child: () => ({ error: mocks.logError, warn: mocks.logWarn, info: mocks.logInfo }),
+  }),
+}))
+
+vi.mock('@upstash/redis', () => ({
+  Redis: class Redis {
+    constructor(cfg: unknown) {
+      mocks.redisCtor(cfg)
+    }
+  },
+}))
+
+vi.mock('@upstash/ratelimit', () => ({
+  Ratelimit: class Ratelimit {
+    static slidingWindow = vi.fn((max: number, window: string) => ({ max, window }))
+    limit = mocks.limit
+    constructor(cfg: unknown) {
+      mocks.ratelimitCtor(cfg)
+    }
+  },
+}))
+
+// The "report once per process" flag is module state, so every test gets a
+// fresh module instance instead of a test-only reset export.
+async function loadModule() {
+  vi.resetModules()
+  return import('@/lib/auth/rate-limit-http')
+}
+
+const OPTS = { prefix: 'test', identifier: 'ip:1', maxRequests: 5, windowMs: 60_000 }
+
+describe('checkRateLimit', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    vi.stubEnv('UPSTASH_REDIS_REST_URL', '')
+    vi.stubEnv('UPSTASH_REDIS_REST_TOKEN', '')
+    vi.stubEnv('NEXT_PUBLIC_SELF_HOSTED', '')
+    vi.stubEnv('NODE_ENV', 'production')
+  })
+
+  afterEach(() => {
+    vi.unstubAllEnvs()
+  })
+
+  describe('Redis not configured', () => {
+    it('fails open on a hosted production deployment but logs one error with the alert flag', async () => {
+      const { checkRateLimit } = await loadModule()
+
+      expect(await checkRateLimit(OPTS)).toEqual({ ok: true })
+      expect(await checkRateLimit({ ...OPTS, identifier: 'ip:2' })).toEqual({ ok: true })
+      expect(await checkRateLimit({ ...OPTS, prefix: 'other' })).toEqual({ ok: true })
+
+      expect(mocks.logError).toHaveBeenCalledTimes(1)
+      const [message, ctx] = mocks.logError.mock.calls[0]
+      expect(message).toMatch(/UPSTASH_REDIS_REST_URL/)
+      expect(message).toMatch(/failing open/)
+      expect(ctx).toMatchObject({ alert: true })
+      expect(mocks.redisCtor).not.toHaveBeenCalled()
+    })
+
+    it('stays quiet on a self-hosted deployment (Redis is optional there)', async () => {
+      vi.stubEnv('NEXT_PUBLIC_SELF_HOSTED', 'true')
+      const { checkRateLimit } = await loadModule()
+
+      expect(await checkRateLimit(OPTS)).toEqual({ ok: true })
+      expect(mocks.logError).not.toHaveBeenCalled()
+    })
+
+    it('stays quiet outside production (local dev and tests are not deployments)', async () => {
+      vi.stubEnv('NODE_ENV', 'development')
+      const { checkRateLimit } = await loadModule()
+
+      expect(await checkRateLimit(OPTS)).toEqual({ ok: true })
+      expect(mocks.logError).not.toHaveBeenCalled()
+    })
+
+    it('reports the limiter as not configured', async () => {
+      const { isRateLimiterConfigured } = await loadModule()
+      expect(isRateLimiterConfigured()).toBe(false)
+
+      vi.stubEnv('UPSTASH_REDIS_REST_URL', 'https://redis.example')
+      expect(isRateLimiterConfigured()).toBe(false)
+
+      vi.stubEnv('UPSTASH_REDIS_REST_TOKEN', 'tok')
+      expect(isRateLimiterConfigured()).toBe(true)
+    })
+  })
+
+  describe('Redis configured', () => {
+    beforeEach(() => {
+      vi.stubEnv('UPSTASH_REDIS_REST_URL', 'https://redis.example')
+      vi.stubEnv('UPSTASH_REDIS_REST_TOKEN', 'tok')
+    })
+
+    it('allows the request when the sliding window has room and logs nothing', async () => {
+      mocks.limit.mockResolvedValue({ success: true, reset: Date.now() + 1000, limit: 5, remaining: 4 })
+      const { checkRateLimit } = await loadModule()
+
+      expect(await checkRateLimit(OPTS)).toEqual({ ok: true })
+      expect(mocks.limit).toHaveBeenCalledWith('ip:1')
+      expect(mocks.redisCtor).toHaveBeenCalledWith({ url: 'https://redis.example', token: 'tok' })
+      expect(mocks.ratelimitCtor).toHaveBeenCalledWith(
+        expect.objectContaining({ prefix: 'test', analytics: false }),
+      )
+      expect(mocks.logError).not.toHaveBeenCalled()
+    })
+
+    it('returns a Swedish 429 with Retry-After and X-RateLimit headers when blocked', async () => {
+      const reset = Date.now() + 30_000
+      mocks.limit.mockResolvedValue({ success: false, reset, limit: 5, remaining: 0 })
+      const { checkRateLimit } = await loadModule()
+
+      const result = await checkRateLimit(OPTS)
+      expect(result.ok).toBe(false)
+      expect(result.response?.status).toBe(429)
+      expect(await result.response?.json()).toEqual({
+        error: 'För många förfrågningar. Försök igen om en stund.',
+      })
+      const retryAfter = Number(result.response?.headers.get('Retry-After'))
+      expect(retryAfter).toBeGreaterThanOrEqual(29)
+      expect(retryAfter).toBeLessThanOrEqual(31)
+      expect(result.response?.headers.get('X-RateLimit-Limit')).toBe('5')
+      expect(result.response?.headers.get('X-RateLimit-Remaining')).toBe('0')
+      expect(result.response?.headers.get('X-RateLimit-Reset')).toBe(String(Math.ceil(reset / 1000)))
+    })
+
+    it('reuses one limiter per prefix/limit/window triple', async () => {
+      mocks.limit.mockResolvedValue({ success: true, reset: 0, limit: 5, remaining: 4 })
+      const { checkRateLimit } = await loadModule()
+
+      await checkRateLimit(OPTS)
+      await checkRateLimit({ ...OPTS, identifier: 'ip:9' })
+      await checkRateLimit({ ...OPTS, maxRequests: 50 })
+
+      expect(mocks.ratelimitCtor).toHaveBeenCalledTimes(2)
+      expect(mocks.redisCtor).toHaveBeenCalledTimes(1)
+    })
+  })
+})
@@ -31,6 +31,22 @@ const MOCK_USER = {
  created_at: '2026-01-01T00:00:00Z',
 }

+const VERIFIED_TOTP = { id: 'f1', status: 'verified', factor_type: 'totp' }
+const UNVERIFIED_TOTP = { id: 'f2', status: 'unverified', factor_type: 'totp' }
+
+/** listFactors() payload: `all` carries everything, the typed arrays only verified ones. */
+function factorList(...factors: Array<typeof VERIFIED_TOTP>) {
+  return {
+    data: {
+      all: factors,
+      totp: factors.filter((f) => f.status === 'verified'),
+      phone: [],
+      webauthn: [],
+    },
+    error: null,
+  }
+}
+
 type MockAuth = Record<string, unknown>

 function useSupabase(auth: MockAuth) {
@@ -39,6 +55,11 @@ function useSupabase(auth: MockAuth) {
  return supabase
 }

+function enableMfa() {
+  vi.stubEnv('NEXT_PUBLIC_REQUIRE_MFA', 'true')
+  vi.stubEnv('NEXT_PUBLIC_SELF_HOSTED', '')
+}
+
 describe('requireAuth', () => {
  beforeEach(() => {
    vi.clearAllMocks()
@@ -142,53 +163,179 @@ describe('requireAuth', () => {
    expect(getUser).not.toHaveBeenCalled()
  })

-  it('returns 403 when MFA is required and AAL2 is not verified', async () => {
-    vi.stubEnv('NEXT_PUBLIC_REQUIRE_MFA', 'true')
-    vi.stubEnv('NEXT_PUBLIC_SELF_HOSTED', '')
-    const getClaims = vi.fn().mockResolvedValue({ data: { claims: CLAIMS }, error: null })
-    const getAuthenticatorAssuranceLevel = vi.fn().mockResolvedValue({
-      data: { currentLevel: 'aal1', nextLevel: 'aal2' },
-      error: null,
+  describe('MFA gate', () => {
+    beforeEach(() => {
+      enableMfa()
+      vi.spyOn(console, 'error').mockImplementation(() => {})
    })
-    useSupabase({ getClaims, mfa: { getAuthenticatorAssuranceLevel } })

-    const result = await requireAuth()
-
-    expect(result.user).toBeNull()
-    expect(result.error?.status).toBe(403)
-    const body = await result.error?.json()
-    expect(body).toEqual({ error: 'MFA verification required' })
-  })
-
-  it('skips the MFA check for bankid_linked users', async () => {
-    vi.stubEnv('NEXT_PUBLIC_REQUIRE_MFA', 'true')
-    vi.stubEnv('NEXT_PUBLIC_SELF_HOSTED', '')
-    const claims = { ...CLAIMS, app_metadata: { provider: 'email', bankid_linked: true } }
-    const getClaims = vi.fn().mockResolvedValue({ data: { claims }, error: null })
-    const getAuthenticatorAssuranceLevel = vi.fn()
-    useSupabase({ getClaims, mfa: { getAuthenticatorAssuranceLevel } })
-
-    const result = await requireAuth()
-
-    expect(result.error).toBeNull()
-    expect(result.user?.id).toBe('user-1')
-    expect(getAuthenticatorAssuranceLevel).not.toHaveBeenCalled()
-  })
-
-  it('passes when MFA is required and the session is already AAL2', async () => {
-    vi.stubEnv('NEXT_PUBLIC_REQUIRE_MFA', 'true')
-    vi.stubEnv('NEXT_PUBLIC_SELF_HOSTED', '')
-    const getClaims = vi.fn().mockResolvedValue({ data: { claims: CLAIMS }, error: null })
-    const getAuthenticatorAssuranceLevel = vi.fn().mockResolvedValue({
-      data: { currentLevel: 'aal2', nextLevel: 'aal2' },
-      error: null,
+    afterEach(() => {
+      vi.restoreAllMocks()
    })
-    useSupabase({ getClaims, mfa: { getAuthenticatorAssuranceLevel } })

-    const result = await requireAuth()
+    it('returns 403 for an AAL1 session when the auth server reports a verified factor', async () => {
+      const getClaims = vi.fn().mockResolvedValue({ data: { claims: CLAIMS }, error: null })
+      const listFactors = vi.fn().mockResolvedValue(factorList(VERIFIED_TOTP))
+      useSupabase({ getClaims, mfa: { listFactors } })

-    expect(result.error).toBeNull()
-    expect(result.user?.id).toBe('user-1')
-    expect(getAuthenticatorAssuranceLevel).toHaveBeenCalledTimes(1)
+      const result = await requireAuth()
+
+      expect(result.user).toBeNull()
+      expect(result.error?.status).toBe(403)
+      const body = await result.error?.json()
+      expect(body).toEqual({ error: 'MFA verification required' })
+      expect(listFactors).toHaveBeenCalledTimes(1)
+    })
+
+    it('never consults the cookie-derived assurance level', async () => {
+      // The attack: the sb-*-auth-token cookie is unsigned JSON, so the
+      // password holder strips `user.factors` and the local
+      // getAuthenticatorAssuranceLevel() reports nextLevel aal1 ("no MFA
+      // enrolled"). The gate must decide on the server's answer instead.
+      const getClaims = vi.fn().mockResolvedValue({ data: { claims: CLAIMS }, error: null })
+      const getAuthenticatorAssuranceLevel = vi.fn().mockResolvedValue({
+        data: { currentLevel: 'aal1', nextLevel: 'aal1' },
+        error: null,
+      })
+      const listFactors = vi.fn().mockResolvedValue(factorList(VERIFIED_TOTP))
+      useSupabase({ getClaims, mfa: { getAuthenticatorAssuranceLevel, listFactors } })
+
+      const result = await requireAuth()
+
+      expect(result.error?.status).toBe(403)
+      expect(getAuthenticatorAssuranceLevel).not.toHaveBeenCalled()
+    })
+
+    it('passes an AAL2 session on the verified claims alone (no listFactors round trip)', async () => {
+      const claims = { ...CLAIMS, aal: 'aal2' }
+      const getClaims = vi.fn().mockResolvedValue({ data: { claims }, error: null })
+      const listFactors = vi.fn()
+      const getAuthenticatorAssuranceLevel = vi.fn()
+      useSupabase({ getClaims, mfa: { listFactors, getAuthenticatorAssuranceLevel } })
+
+      const result = await requireAuth()
+
+      expect(result.error).toBeNull()
+      expect(result.user?.id).toBe('user-1')
+      expect(listFactors).not.toHaveBeenCalled()
+      expect(getAuthenticatorAssuranceLevel).not.toHaveBeenCalled()
+    })
+
+    it('passes an AAL1 session when the auth server reports no verified factor', async () => {
+      const getClaims = vi.fn().mockResolvedValue({ data: { claims: CLAIMS }, error: null })
+      const listFactors = vi.fn().mockResolvedValue(factorList())
+      useSupabase({ getClaims, mfa: { listFactors } })
+
+      const result = await requireAuth()
+
+      expect(result.error).toBeNull()
+      expect(result.user?.id).toBe('user-1')
+      expect(listFactors).toHaveBeenCalledTimes(1)
+    })
+
+    it('does not count an unverified (enrolment in progress) factor as a step-up target', async () => {
+      const getClaims = vi.fn().mockResolvedValue({ data: { claims: CLAIMS }, error: null })
+      const listFactors = vi.fn().mockResolvedValue(factorList(UNVERIFIED_TOTP))
+      useSupabase({ getClaims, mfa: { listFactors } })
+
+      const result = await requireAuth()
+
+      expect(result.error).toBeNull()
+    })
+
+    it('reads a verified phone factor from the typed array when `all` is absent', async () => {
+      const getClaims = vi.fn().mockResolvedValue({ data: { claims: CLAIMS }, error: null })
+      const listFactors = vi.fn().mockResolvedValue({
+        data: { phone: [{ id: 'p1', status: 'verified', factor_type: 'phone' }] },
+        error: null,
+      })
+      useSupabase({ getClaims, mfa: { listFactors } })
+
+      const result = await requireAuth()
+
+      expect(result.error?.status).toBe(403)
+    })
+
+    it('treats a session whose verified claims carry no aal as not assured', async () => {
+      const { aal: _aal, ...claims } = CLAIMS
+      const getClaims = vi.fn().mockResolvedValue({ data: { claims }, error: null })
+      const listFactors = vi.fn().mockResolvedValue(factorList(VERIFIED_TOTP))
+      useSupabase({ getClaims, mfa: { listFactors } })
+
+      const result = await requireAuth()
+
+      expect(result.error?.status).toBe(403)
+    })
+
+    it('fails closed when listFactors returns an error', async () => {
+      const getClaims = vi.fn().mockResolvedValue({ data: { claims: CLAIMS }, error: null })
+      const listFactors = vi.fn().mockResolvedValue({
+        data: null,
+        error: { name: 'AuthApiError', message: 'upstream unavailable' },
+      })
+      useSupabase({ getClaims, mfa: { listFactors } })
+
+      const result = await requireAuth()
+
+      expect(result.error?.status).toBe(403)
+    })
+
+    it('fails closed when listFactors throws', async () => {
+      const getClaims = vi.fn().mockResolvedValue({ data: { claims: CLAIMS }, error: null })
+      const listFactors = vi.fn().mockRejectedValue(new Error('network down'))
+      useSupabase({ getClaims, mfa: { listFactors } })
+
+      const result = await requireAuth()
+
+      expect(result.error?.status).toBe(403)
+    })
+
+    it('fails closed when the client exposes no mfa API at all', async () => {
+      const getClaims = vi.fn().mockResolvedValue({ data: { claims: CLAIMS }, error: null })
+      useSupabase({ getClaims })
+
+      const result = await requireAuth()
+
+      expect(result.error?.status).toBe(403)
+    })
+
+    it('asks listFactors on the getUser fallback path and refuses a verified factor', async () => {
+      // No verified claims exist here (getClaims failed), so the level is
+      // unknown: a verified factor means the session must be refused.
+      const getClaims = vi.fn().mockRejectedValue(new Error('jwks fetch failed'))
+      const getUser = vi.fn().mockResolvedValue({ data: { user: MOCK_USER }, error: null })
+      const listFactors = vi.fn().mockResolvedValue(factorList(VERIFIED_TOTP))
+      useSupabase({ getClaims, getUser, mfa: { listFactors } })
+
+      const result = await requireAuth()
+
+      expect(result.error?.status).toBe(403)
+      expect(listFactors).toHaveBeenCalledTimes(1)
+    })
+
+    it('passes a factor-less user on the getUser fallback path', async () => {
+      const getUser = vi.fn().mockResolvedValue({ data: { user: MOCK_USER }, error: null })
+      const listFactors = vi.fn().mockResolvedValue(factorList())
+      useSupabase({ getUser, mfa: { listFactors } })
+
+      const result = await requireAuth()
+
+      expect(result.error).toBeNull()
+      expect(result.user?.id).toBe('user-1')
+      expect(listFactors).toHaveBeenCalledTimes(1)
+    })
+
+    it('skips the MFA check for bankid_linked users', async () => {
+      const claims = { ...CLAIMS, app_metadata: { provider: 'email', bankid_linked: true } }
+      const getClaims = vi.fn().mockResolvedValue({ data: { claims }, error: null })
+      const listFactors = vi.fn()
+      useSupabase({ getClaims, mfa: { listFactors } })
+
+      const result = await requireAuth()
+
+      expect(result.error).toBeNull()
+      expect(result.user?.id).toBe('user-1')
+      expect(listFactors).not.toHaveBeenCalled()
+    })
  })
 })
@@ -1,5 +1,22 @@
 import type { SupabaseClient } from '@supabase/supabase-js'
 import { createServiceClientNoCookies } from './api-keys'
+import { fetchAllRows } from '@/lib/supabase/fetch-all'
+import { scopeKind, type ApiKeyScope } from './scope-catalog'
+
+/**
+ * What an OAuth consent may grant: which redirect URIs a code may be sent
+ * to, who the client behind a URI is, and which scopes the consenting user's
+ * role in the selected company permits.
+ */
+
+// ── Redirect URI allowlist ─────────────────────────────────────
+
+/**
+ * Identity of a built-in client, derived from the redirect URI pattern that
+ * matched. Rendered on the consent page so the user can tell a real Claude /
+ * ChatGPT connector from a look-alike registration.
+ */
+export type BuiltInProvider = 'claude' | 'chatgpt' | 'local'

 /**
 * Built-in redirect URI patterns. These bypass the DB lookup entirely so
@@ -11,38 +28,81 @@ import { createServiceClientNoCookies } from './api-keys'
 * callback for already-published apps; both are documented at
 * developers.openai.com/apps-sdk/build/auth.
 */
-export const BUILT_IN_REDIRECT_PATTERNS: readonly RegExp[] = [
-  /^https:\/\/claude\.ai\/api\//,
-  /^https:\/\/claude\.com\/api\//,
-  /^https:\/\/chatgpt\.com\/connector\/oauth\//,
-  /^https:\/\/chatgpt\.com\/connector_platform_oauth_redirect$/,
-  /^http:\/\/localhost(:\d+)?(\/|$)/,
-  /^http:\/\/127\.0\.0\.1(:\d+)?(\/|$)/,
+const BUILT_IN_PATTERNS: readonly { pattern: RegExp; provider: BuiltInProvider }[] = [
+  { pattern: /^https:\/\/claude\.ai\/api\//, provider: 'claude' },
+  { pattern: /^https:\/\/claude\.com\/api\//, provider: 'claude' },
+  { pattern: /^https:\/\/chatgpt\.com\/connector\/oauth\//, provider: 'chatgpt' },
+  { pattern: /^https:\/\/chatgpt\.com\/connector_platform_oauth_redirect$/, provider: 'chatgpt' },
+  { pattern: /^http:\/\/localhost(:\d+)?(\/|$)/, provider: 'local' },
+  { pattern: /^http:\/\/127\.0\.0\.1(:\d+)?(\/|$)/, provider: 'local' },
 ]

-export function isBuiltInRedirectUri(uri: string): boolean {
-  return BUILT_IN_REDIRECT_PATTERNS.some((pattern) => pattern.test(uri))
+export const BUILT_IN_REDIRECT_PATTERNS: readonly RegExp[] = BUILT_IN_PATTERNS.map((p) => p.pattern)
+
+/** Which built-in client a redirect URI belongs to, or null when none matches. */
+export function builtInRedirectProvider(uri: string): BuiltInProvider | null {
+  if (typeof uri !== 'string') return null
+  return BUILT_IN_PATTERNS.find(({ pattern }) => pattern.test(uri))?.provider ?? null
 }

+export function isBuiltInRedirectUri(uri: string): boolean {
+  return builtInRedirectProvider(uri) !== null
+}
+
+export type RedirectUriResolution =
+  | { allowed: true; kind: 'built_in'; provider: BuiltInProvider }
+  | {
+      allowed: true
+      kind: 'registered'
+      /** Display name the registering user gave the client (settings UI). */
+      clientName: string
+      /** True when the consenting user registered the URI themselves. */
+      registeredByConsentingUser: boolean
+    }
+  | { allowed: false }
+
+export interface RedirectUriOptions {
+  /**
+   * The user about to consent at /authorize. When set, a DB-registered URI is
+   * accepted only if this user registered it, or shares at least one company
+   * with the user who did. Any authenticated user can insert into
+   * oauth_client_registrations (RLS: user_id = auth.uid()), so without this
+   * binding a stranger's registration would be a valid phishing target for
+   * every account on the instance. Built-in patterns are unaffected.
+   *
+   * Omitted by the anonymous /register endpoint, which has no user to bind
+   * to: it accepts any active registration, which is harmless because the
+   * code is only ever minted at /authorize where the binding is enforced.
+   */
+  consentingUserId?: string
+}
+
+type RegistrationRow = { id: string; user_id: string; client_name: string }
+
 /**
- * Resolve whether a redirect URI is allowed. Built-in patterns short-circuit;
- * otherwise we look for a non-revoked registration in oauth_client_registrations.
+ * Resolve a redirect URI to the client behind it. Built-in patterns
+ * short-circuit; otherwise we look for a non-revoked registration in
+ * oauth_client_registrations and, when a consenting user is given, check
+ * that the registration is theirs or a colleague's.
 *
- * The supabase client should be supplied explicitly by the caller so the
- * trust boundary is visible at the callsite (SOC 2 CC6.1). When omitted, the
- * function falls back to a service-role client: required for the /register
- * endpoint which has no user session yet. The lookup is by exact URI; the
- * unique partial index on the table ensures at most one active row.
+ * The lookup runs with the service role. The table's SELECT policy is
+ * user_id = auth.uid(), so a user-scoped client cannot see a colleague's
+ * registration at all; the trust boundary is instead the explicit binding to
+ * `consentingUserId` below (SOC 2 CC6.1). Callers may pass a client (the
+ * /register endpoint already holds one); otherwise one is constructed here.
 *
 * Fails closed on any error (client construction, DB query): for an
- * allowlist, "unknown → deny" is the safe default.
+ * allowlist, "unknown → deny" is the safe default. The lookup is by exact
+ * URI; the unique partial index on the table ensures at most one active row.
 */
-export async function isAllowedRedirectUri(
+export async function resolveRedirectUri(
  uri: string,
-  supabase?: SupabaseClient
-): Promise<boolean> {
-  if (typeof uri !== 'string' || uri.length === 0) return false
-  if (isBuiltInRedirectUri(uri)) return true
+  supabase?: SupabaseClient,
+  options: RedirectUriOptions = {},
+): Promise<RedirectUriResolution> {
+  if (typeof uri !== 'string' || uri.length === 0) return { allowed: false }
+  const provider = builtInRedirectProvider(uri)
+  if (provider) return { allowed: true, kind: 'built_in', provider }

  // Service-role client construction can throw when Supabase env vars are
  // absent (unit tests, misconfigured deploys). Treat that as "not allowed":
@@ -51,17 +111,124 @@ export async function isAllowedRedirectUri(
  try {
    client = supabase ?? createServiceClientNoCookies()
  } catch {
-    return false
+    return { allowed: false }
  }

  const { data, error } = await client
    .from('oauth_client_registrations')
-    .select('id')
+    .select('id, user_id, client_name')
    .eq('redirect_uri', uri)
    .is('revoked_at', null)
    .limit(1)
    .maybeSingle()

-  if (error) return false
-  return data !== null
+  if (error || !data) return { allowed: false }
+  const registration = data as RegistrationRow
+
+  const { consentingUserId } = options
+  if (consentingUserId === undefined) {
+    return { allowed: true, kind: 'registered', clientName: registration.client_name, registeredByConsentingUser: false }
+  }
+
+  if (registration.user_id === consentingUserId) {
+    return { allowed: true, kind: 'registered', clientName: registration.client_name, registeredByConsentingUser: true }
+  }
+
+  const shared = await usersShareCompany(client, consentingUserId, registration.user_id)
+  if (!shared) return { allowed: false }
+  return { allowed: true, kind: 'registered', clientName: registration.client_name, registeredByConsentingUser: false }
+}
+
+/**
+ * Boolean view of resolveRedirectUri, kept for the callers that only need
+ * the allow/deny answer (the /register endpoint and its tests).
+ */
+export async function isAllowedRedirectUri(
+  uri: string,
+  supabase?: SupabaseClient,
+  options: RedirectUriOptions = {},
+): Promise<boolean> {
+  const resolution = await resolveRedirectUri(uri, supabase, options)
+  return resolution.allowed
+}
+
+/**
+ * True when the two users are both members of at least one common company.
+ * Both membership lists are paginated (a byrå consultant can sit in hundreds
+ * of companies) and intersected here rather than via an `.in()` filter, whose
+ * URL length would grow with the membership count. Any query failure counts
+ * as "not shared" (fail closed).
+ */
+async function usersShareCompany(
+  client: SupabaseClient,
+  userA: string,
+  userB: string,
+): Promise<boolean> {
+  try {
+    const companyIdsOf = (userId: string) =>
+      fetchAllRows<{ company_id: string }>(({ from, to }) =>
+        client
+          .from('company_members')
+          .select('company_id')
+          .eq('user_id', userId)
+          .order('id', { ascending: true })
+          .range(from, to),
+      )
+    const [rowsA, rowsB] = await Promise.all([companyIdsOf(userA), companyIdsOf(userB)])
+    const companiesA = new Set(rowsA.map((r) => r.company_id))
+    return rowsB.some((r) => companiesA.has(r.company_id))
+  } catch {
+    return false
+  }
+}
+
+// ── Role ceiling ──────────────────────────────────────────────
+
+/** Company roles whose members may hold write, manage, approve or signoff scopes. */
+const WRITER_ROLES: ReadonlySet<string> = new Set(['owner', 'admin', 'member'])
+
+/**
+ * Cap a scope set to what the consenting user's role in the selected company
+ * permits. Mirrors the app's own gate: `viewer` is read-only everywhere
+ * (withRouteContext requireWrite, the DB-level enforce_company_writer_role
+ * trigger), while owner/admin/member may hold every scope. The stage+approve
+ * segregation-of-duties combination is not capped by role, matching
+ * app/api/settings/api-keys (warn, acknowledge, record), so the consent page
+ * states the rule and the token route records the acknowledgement.
+ *
+ * A null role (no membership row) or an unrecognised role string caps to
+ * read-only: an unknown privilege level must never widen the grant.
+ */
+export function capScopesForRole(
+  scopes: readonly ApiKeyScope[],
+  role: string | null,
+): ApiKeyScope[] {
+  if (role !== null && WRITER_ROLES.has(role)) return [...scopes]
+  return scopes.filter((s) => scopeKind(s) === 'read')
+}
+
+export type CompanyRoleLookup =
+  | { role: string | null; error: null }
+  | { role: null; error: string }
+
+/**
+ * The user's role in a company, or null when no membership row exists. A
+ * failed query is reported separately so callers can fail loudly instead of
+ * silently downgrading (or widening) a grant on a transient error.
+ */
+export async function lookupCompanyRole(
+  supabase: SupabaseClient,
+  userId: string,
+  companyId: string,
+): Promise<CompanyRoleLookup> {
+  const { data, error } = await supabase
+    .from('company_members')
+    .select('role')
+    .eq('company_id', companyId)
+    .eq('user_id', userId)
+    .maybeSingle()
+
+  if (error) return { role: null, error: error.message }
+  const role = (data as { role?: unknown } | null)?.role
+  return { role: typeof role === 'string' ? role : null, error: null }
 }
@@ -28,6 +28,14 @@ export interface AuthCodePayload {
   * to ALL_SCOPES so existing Claude flows are unaffected.
   */
  scopes?: string[]
+  /**
+   * Company shown on the consent page and used to cap `scopes` to the user's
+   * role there. The token route binds the key to it and re-checks the role
+   * cap against it. Null for an account with no company yet (issue #1814);
+   * undefined on codes minted before the field existed, where the token
+   * route falls back to resolving the active company itself.
+   */
+  companyId?: string | null
  exp: number
 }

@@ -0,0 +1,134 @@
+import { NextResponse } from 'next/server'
+import { createClient } from '@/lib/supabase/server'
+import { createLogger } from '@/lib/logger'
+
+/**
+ * Bind the completion of a browser-driven OAuth/consent flow to the user who
+ * started it.
+ *
+ * Our OAuth callbacks (Enable Banking, Stripe Connect, WooCommerce wc-auth)
+ * locate the pending connection row by the single-use `oauth_state` token and
+ * then finalize it for that row's `user_id` / `company_id`. The token proves
+ * the callback belongs to a flow WE started; it does not prove that the
+ * browser completing it belongs to the user who started it. Without this
+ * check, a victim who is lured into completing a consent an attacker
+ * initiated (the authorize URL is shareable) has their bank / Stripe / store
+ * attached to the attacker's company.
+ *
+ * Consent redirects are top-level navigations, so on the legitimate path the
+ * initiator's own session cookies arrive with the callback. This helper reads
+ * that cookie session and compares it to the expected initiator.
+ *
+ * Outcomes:
+ *   - ok: the session user is the initiator; carry on.
+ *   - no_session: nobody is signed in (expired mid-flow, cookies cleared).
+ *     `response` redirects to /login?next=<this callback URL> so the initiator
+ *     can sign in and the callback re-runs with the same code + state.
+ *   - mismatch: a different user is signed in. `response` is a 403 in the
+ *     canonical error envelope; a route whose UX is a settings redirect
+ *     inspects `reason` and builds its own redirect instead. The mismatch is
+ *     logged with both ids redacted to prefixes.
+ *
+ * Deliberately not `requireAuth()`: this is an equality check on identity,
+ * not an authorization gate. The route that STARTED the flow already ran the
+ * MFA-enforcing guard for this user, and a 403 here for an aal1 session would
+ * strand the user (the callback has no MFA prompt to send them to).
+ */
+
+const log = createLogger('auth/oauth-flow-binding')
+
+/** Swedish user-facing message for the mismatch outcome (shared by callers). */
+export const FLOW_INITIATOR_MISMATCH_MESSAGE =
+  'Anslutningen kunde inte slutföras: den startades från ett annat användarkonto än det du är inloggad med. Logga in med det kontot eller starta anslutningen på nytt.'
+
+export const FLOW_INITIATOR_MISMATCH_MESSAGE_EN =
+  'The connection could not be completed: it was started from a different user account than the one you are signed in with. Sign in with that account or start the connection again.'
+
+export type FlowInitiatorResult =
+  | { ok: true; userId: string }
+  | { ok: false; reason: 'no_session'; response: Response }
+  | { ok: false; reason: 'mismatch'; response: Response; sessionUserId: string }
+
+export interface RequireFlowInitiatorOptions {
+  /** Short label for the log line, e.g. 'stripe.callback'. */
+  flow?: string
+}
+
+/**
+ * Shorten a user id to a stable prefix for log lines. Enough to correlate two
+ * log records, not enough to identify the account outside the database.
+ */
+export function redactUserId(id: string | null | undefined): string {
+  if (!id) return '(none)'
+  return id.length <= 8 ? id : `${id.slice(0, 8)}...`
+}
+
+/**
+ * The /login redirect for a callback reached without a session. `next` is the
+ * callback's own path + query (same-origin relative, which is the only form
+ * the login page's safeReturnTo accepts), so signing in resumes the flow.
+ */
+export function buildLoginRedirect(request: Request): Response {
+  const current = new URL(request.url)
+  const appOrigin = process.env.NEXT_PUBLIC_APP_URL || current.origin
+  const next = `${current.pathname}${current.search}`
+  const login = new URL('/login', appOrigin)
+  login.searchParams.set('next', next)
+  return NextResponse.redirect(login.toString())
+}
+
+export async function requireFlowInitiator(
+  request: Request,
+  expectedUserId: string,
+  options: RequireFlowInitiatorOptions = {},
+): Promise<FlowInitiatorResult> {
+  const flow = options.flow ?? 'oauth-callback'
+  const path = new URL(request.url).pathname
+
+  let sessionUserId: string | null = null
+  try {
+    const supabase = await createClient()
+    const { data, error } = await supabase.auth.getUser()
+    if (!error && data?.user?.id) sessionUserId = data.user.id
+  } catch (err) {
+    // Fail closed: an auth outage or a missing request scope is treated as
+    // "no session". The login redirect below re-runs the callback once a
+    // session can be read, nothing is finalized on a guess.
+    log.error('could not read the cookie session for an OAuth callback', err as Error, {
+      flow,
+      path,
+    })
+  }
+
+  if (!sessionUserId) {
+    log.warn('oauth callback reached without a session; sending to login', {
+      flow,
+      path,
+      expectedUser: redactUserId(expectedUserId),
+    })
+    return { ok: false, reason: 'no_session', response: buildLoginRedirect(request) }
+  }
+
+  if (sessionUserId !== expectedUserId) {
+    log.warn('oauth callback completed by a different user than the initiator', {
+      flow,
+      path,
+      expectedUser: redactUserId(expectedUserId),
+      sessionUser: redactUserId(sessionUserId),
+      alert: true,
+    })
+    const response = NextResponse.json(
+      {
+        error: {
+          code: 'OAUTH_FLOW_INITIATOR_MISMATCH',
+          message: FLOW_INITIATOR_MISMATCH_MESSAGE,
+          message_en: FLOW_INITIATOR_MISMATCH_MESSAGE_EN,
+        },
+      },
+      { status: 403 },
+    )
+    return { ok: false, reason: 'mismatch', response, sessionUserId }
+  }
+
+  return { ok: true, userId: sessionUserId }
+}
@@ -1,9 +1,22 @@
 import { Ratelimit } from '@upstash/ratelimit'
 import { Redis } from '@upstash/redis'
 import { NextResponse } from 'next/server'
+import { isSelfHosted } from '@/lib/env/public-flags'
+import { createLogger } from '@/lib/logger'
+
+const log = createLogger('auth.rate-limit')

 let redis: Redis | null = null

+/**
+ * Whether the Upstash credentials the limiter needs are present. Exposed so
+ * health / version surfaces can report the limiter's state instead of every
+ * caller re-reading the env.
+ */
+export function isRateLimiterConfigured(): boolean {
+  return Boolean(process.env.UPSTASH_REDIS_REST_URL && process.env.UPSTASH_REDIS_REST_TOKEN)
+}
+
 function getRedis(): Redis | null {
  if (redis) return redis
  const url = process.env.UPSTASH_REDIS_REST_URL
@@ -33,6 +46,31 @@ function getLimiter(prefix: string, maxRequests: number, windowMs: number): Rate
  return limiter
 }

+// Once per process: the first rate-limited request on a hosted deployment
+// without Redis produces one error record. Repeating it per request would
+// drown the logs the alert is meant to surface in.
+let reportedNotConfigured = false
+
+/**
+ * Fail-open is deliberate for local dev and self-hosted installs (no Redis
+ * required to run the product). On the hosted product it is a
+ * misconfiguration: every limiter-protected surface (MCP OAuth registration,
+ * sandbox seeding, client log ingestion, webshop connects) is unthrottled.
+ * Say so loudly, exactly once, at error level with the alert flag so the
+ * observability sink pages on it. Never fail closed here: that would turn a
+ * missing env var into a 503 on every protected route.
+ */
+function reportNotConfiguredOnce(): void {
+  if (reportedNotConfigured) return
+  reportedNotConfigured = true
+  if (isSelfHosted()) return
+  if (process.env.NODE_ENV !== 'production') return
+  log.error(
+    'HTTP rate limiting is disabled: UPSTASH_REDIS_REST_URL / UPSTASH_REDIS_REST_TOKEN are not set on a hosted deployment; checkRateLimit() is failing open',
+    { alert: true, operation: 'rate-limit.not-configured' },
+  )
+}
+
 export interface RateLimitOptions {
  prefix: string
  identifier: string
@@ -54,11 +92,16 @@ export interface RateLimitResult {
 * No-ops (allows the request) when Upstash env vars are not configured:
 * intentional so local dev and self-hosted deployments without Redis still work.
 * Production hosted deployments must set UPSTASH_REDIS_REST_URL/TOKEN for the
- * limit to be enforced; absence is logged once at startup by other call sites.
+ * limit to be enforced; a hosted process without them logs one error-level
+ * record (see reportNotConfiguredOnce) and `isRateLimiterConfigured()` reports
+ * the state for health surfaces.
 */
 export async function checkRateLimit(opts: RateLimitOptions): Promise<RateLimitResult> {
  const limiter = getLimiter(opts.prefix, opts.maxRequests, opts.windowMs)
-  if (!limiter) return { ok: true }
+  if (!limiter) {
+    reportNotConfiguredOnce()
+    return { ok: true }
+  }

  const { success, reset, limit, remaining } = await limiter.limit(opts.identifier)
  if (success) return { ok: true }
@@ -1,7 +1,7 @@
 import { createClient } from '@/lib/supabase/server'
 import { NextResponse } from 'next/server'
 import { shouldEnforceMfa } from './mfa'
-import type { User, SupabaseClient } from '@supabase/supabase-js'
+import type { JwtPayload, User, SupabaseClient } from '@supabase/supabase-js'
 import { claimsPinned, userFromClaims } from './claims'

 type AuthResult =
@@ -32,19 +32,23 @@ export async function requireAuth(): Promise<AuthResult> {
  const supabase = await createClient()

  let user: User | null = null
+  // The signature-verified claims, kept for the MFA gate below: null on the
+  // getUser fallback path, where no locally verified claims exist.
+  let claims: JwtPayload | null = null
  try {
    // The typeof guard keeps legacy test mocks (auth object with only
    // getUser) on the old path.
    if (typeof supabase.auth.getClaims === 'function') {
      const { data } = await supabase.auth.getClaims()
-      const claims = data?.claims
-      if (claims?.sub) {
-        if (claimsPinned(claims)) {
-          user = userFromClaims(claims)
+      const verified = data?.claims
+      if (verified?.sub) {
+        if (claimsPinned(verified)) {
+          claims = verified
+          user = userFromClaims(verified)
        } else {
          console.error('requireAuth: getClaims iss/aud pinning failed; falling back to getUser', {
-            iss: claims.iss,
-            aud: claims.aud,
+            iss: verified.iss,
+            aud: verified.aud,
          })
        }
      }
@@ -68,16 +72,73 @@ export async function requireAuth(): Promise<AuthResult> {
    }
  }

-  if (shouldEnforceMfa(user)) {
-    const { data: aal } = await supabase.auth.mfa.getAuthenticatorAssuranceLevel()
-    if (aal?.nextLevel === 'aal2' && aal?.currentLevel !== 'aal2') {
-      return {
-        user: null,
-        supabase,
-        error: NextResponse.json({ error: 'MFA verification required' }, { status: 403 }),
-      }
+  if (shouldEnforceMfa(user) && !(await sessionIsMfaAssured(supabase, claims))) {
+    return {
+      user: null,
+      supabase,
+      error: NextResponse.json({ error: 'MFA verification required' }, { status: 403 }),
    }
  }

  return { user, supabase, error: null }
 }
+
+/**
+ * Whether the session may pass the MFA gate.
+ *
+ * An AAL2 session, per the signature-verified claims, passes with no extra
+ * round trip. Anything else (AAL1, no `aal` claim, or the getUser fallback
+ * path where no verified claims exist) asks the auth server through
+ * listFactors() (a getUser() call under the hood) whether a verified factor
+ * exists: if one does, the session is stuck below the level it could reach
+ * and is refused. A failed or throwing lookup is refused too (fail closed):
+ * the alternative lets a transient auth error switch MFA off.
+ *
+ * Never `mfa.getAuthenticatorAssuranceLevel()` without a JWT: its `nextLevel`
+ * is computed from `session.user.factors`, i.e. from the unsigned
+ * sb-*-auth-token cookie, which whoever holds the password can edit to hide
+ * the factor and turn an enrolled account into a "no MFA needed" one
+ * (security audit 2026-09). The cost of the honest check is one listFactors
+ * round trip per API request for AAL1 sessions of users without a factor.
+ */
+async function sessionIsMfaAssured(
+  supabase: SupabaseClient,
+  claims: JwtPayload | null,
+): Promise<boolean> {
+  if (claims?.aal === 'aal2') return true
+
+  try {
+    const { data, error } = await supabase.auth.mfa.listFactors()
+    if (error || !data) {
+      console.error('requireAuth: listFactors failed; treating session as not MFA-assured', error)
+      return false
+    }
+    return !factorsIncludeVerified(data)
+  } catch (err) {
+    console.error('requireAuth: listFactors threw; treating session as not MFA-assured', err)
+    return false
+  }
+}
+
+type FactorList = ReadonlyArray<{ status: string }> | undefined
+
+/**
+ * Whether a listFactors() payload contains a verified factor of any type.
+ * `all` carries every factor; the typed arrays carry only the verified ones.
+ * Both are consulted so a payload missing either shape still reads right.
+ */
+function factorsIncludeVerified(data: {
+  all?: FactorList
+  totp?: FactorList
+  phone?: FactorList
+  webauthn?: FactorList
+}): boolean {
+  const verified = (list: FactorList) =>
+    list?.some((factor) => factor.status === 'verified') ?? false
+  return (
+    verified(data.all) ||
+    verified(data.totp) ||
+    verified(data.phone) ||
+    verified(data.webauthn)
+  )
+}