Files
sattle/src/lnurlcash/passkeys.registration.cases.ts
T

246 lines
9.1 KiB
TypeScript

// Passkey engine tests. The WebAuthn ceremony is faked by an injected
// authenticator whose PRF output is HMAC-SHA256(credential secret, salt) -
// the real extension's exact contract: deterministic per credential+salt,
// unguessable without the authenticator. Everything except a real
// authenticator's touch is covered here.
import {beforeEach, describe, expect, it} from 'vitest'
import {hmac} from '@noble/hashes/hmac.js'
import {sha256} from '@noble/hashes/sha2.js'
import {bytesToHex} from '@noble/hashes/utils.js'
import type {CeremonyCredential, PasskeyCredentials} from './passkeys'
import {
derivePasskeyWrapKey,
getPasskeyPrfOutput,
hasPasskeySlots,
migrateLegacyPasskeySlots,
passkeySupported,
readPasskeySlots,
registerPasskey,
removePasskey,
rewrapAllSlots,
unlockWithPasskey,
unwrapLinkingKeyWithPrf,
wrapLinkingKeyWithPrf,
} from './passkeys'
import {
decryptRecord,
decryptSavedLinkingKey,
deriveBearerAesKey,
ensureSavedKeyOwner,
encryptRecord,
linkingPubKeyHex,
savedKeyOwnerId,
saveLinkingKey,
} from './keys'
import {parseJsonObject, parseJsonObjectArray, stubLocalStorage} from './test-utils'
const LINKING_KEY = new Uint8Array(32).fill(7)
const OTHER_LINKING_KEY = new Uint8Array(32).fill(9)
const PRF_OUTPUT = new Uint8Array(32).fill(3)
const OTHER_PRF_OUTPUT = new Uint8Array(32).fill(4)
const toBytes = (source: BufferSource): Uint8Array =>
source instanceof ArrayBuffer
? new Uint8Array(source)
: new Uint8Array(source.buffer, source.byteOffset, source.byteLength)
// Fake platform authenticator: holds credentials (id -> secret), evaluates
// PRF as HMAC-SHA256(secret, salt). Flags emulate the authenticator quirks
// found in the wild: PRF unsupported, results only on get, results never.
class FakeAuthenticator implements PasskeyCredentials {
// id typed Uint8Array<ArrayBuffer>: rawId must satisfy BufferSource
private held = new Map<string, {id: Uint8Array<ArrayBuffer>; secret: Uint8Array}>()
supportsPrf = true
prfResultsOnCreate = true
prfResultsOnGet = true
createCalls = 0
getCalls = 0
create = async (options?: CredentialCreationOptions): Promise<CeremonyCredential | null> => {
this.createCalls += 1
const salt = options?.publicKey?.extensions?.prf?.eval?.first
const id = crypto.getRandomValues(new Uint8Array(16))
const secret = crypto.getRandomValues(new Uint8Array(32))
this.held.set(bytesToHex(id), {id, secret})
return {
type: 'public-key',
rawId: id,
getClientExtensionResults: () => ({
prf:
this.supportsPrf && salt
? {
enabled: true,
...(this.prfResultsOnCreate ? {results: {first: this.prf(secret, salt)}} : {}),
}
: {},
}),
}
}
// answers with the first allowed credential it holds, like a real
// authenticator picking among allowCredentials; null when it holds none
get = async (options?: CredentialRequestOptions): Promise<CeremonyCredential | null> => {
this.getCalls += 1
const pk = options?.publicKey
const allowed = (pk?.allowCredentials ?? []).map((d) => bytesToHex(toBytes(d.id)))
const match = allowed.find((hex) => this.held.has(hex))
const held = match ? this.held.get(match) : undefined
if (!held) return null
const salt = pk?.extensions?.prf?.eval?.first
return {
type: 'public-key',
rawId: held.id,
getClientExtensionResults: () => ({
prf:
salt && this.prfResultsOnGet
? {enabled: true, results: {first: this.prf(held.secret, salt)}}
: {},
}),
}
}
// simulates the passkey's secret changing underneath a slot (credential
// re-created on the authenticator while the slot stayed behind)
rotateSecret = (credentialId: string): void => {
const held = this.held.get(credentialId)
if (held) held.secret = crypto.getRandomValues(new Uint8Array(32))
}
private prf = (secret: Uint8Array, salt: BufferSource): Uint8Array<ArrayBuffer> => {
// set into a fresh array: hmac returns Uint8Array<ArrayBufferLike>,
// which BufferSource rejects
const out = new Uint8Array(32)
out.set(hmac(sha256, secret, toBytes(salt)))
return out
}
}
const readRawSlots = (): Array<Record<string, unknown>> =>
parseJsonObjectArray(localStorage.getItem('sattle_passkey_slots') ?? '[]')
const writeRawSlots = (slots: Array<Record<string, unknown>>): void => {
localStorage.setItem('sattle_passkey_slots', JSON.stringify(slots))
}
const removeSavedOwnerMarker = (): void => {
const stored = parseJsonObject(localStorage.getItem('sattle_linking_key') ?? '{}')
delete stored.ownerId
delete stored.version
localStorage.setItem('sattle_linking_key', JSON.stringify(stored))
}
beforeEach(async () => {
stubLocalStorage()
await saveLinkingKey(LINKING_KEY)
})
describe('registration and unlock', () => {
it('registers a passkey and unlocks the same linking key', async () => {
const auth = new FakeAuthenticator()
const slot = await registerPasskey(LINKING_KEY, {
credentials: auth,
name: 'laptop',
})
expect(slot.name).toBe('laptop')
expect(readPasskeySlots()).toEqual([slot])
expect(hasPasskeySlots()).toBe(true)
const unwrapped = await unlockWithPasskey({credentials: auth})
expect(bytesToHex(unwrapped)).toBe(bytesToHex(LINKING_KEY))
})
it('never stores the linking key in the clear', async () => {
const auth = new FakeAuthenticator()
await registerPasskey(LINKING_KEY, {credentials: auth})
const raw = localStorage.getItem('sattle_passkey_slots')
expect(raw).toBeTruthy()
expect(raw).not.toContain(bytesToHex(LINKING_KEY))
})
it('yields the same key material unlock(password) yields', async () => {
const linkingKey = crypto.getRandomValues(new Uint8Array(32))
await saveLinkingKey(linkingKey, 'correct horse')
const auth = new FakeAuthenticator()
await registerPasskey(linkingKey, {credentials: auth})
const viaPassword = await decryptSavedLinkingKey('correct horse')
const viaPasskey = await unlockWithPasskey({credentials: auth})
expect(bytesToHex(viaPasskey)).toBe(bytesToHex(viaPassword))
// and the practical consequence: a bearer record encrypted after a
// password unlock decrypts after a passkey unlock
const passwordAes = await deriveBearerAesKey(viaPassword)
const record = await encryptRecord(passwordAes, {note: 'still readable'})
const passkeyAes = await deriveBearerAesKey(viaPasskey)
await expect(decryptRecord(passkeyAes, record)).resolves.toEqual({
note: 'still readable',
})
})
it('falls back to a get ceremony when create only reports prf.enabled', async () => {
const auth = new FakeAuthenticator()
auth.prfResultsOnCreate = false
const slot = await registerPasskey(LINKING_KEY, {credentials: auth})
expect(auth.getCalls).toBe(1)
const unwrapped = await unlockWithPasskey({credentials: auth})
expect(bytesToHex(unwrapped)).toBe(bytesToHex(LINKING_KEY))
expect(readPasskeySlots()[0]?.credentialId).toBe(slot.credentialId)
})
it('refuses registration when the authenticator has no PRF support', async () => {
const auth = new FakeAuthenticator()
auth.supportsPrf = false
await expect(registerPasskey(LINKING_KEY, {credentials: auth})).rejects.toThrow('PRF')
expect(hasPasskeySlots()).toBe(false)
})
it('throws on a cancelled registration ceremony', async () => {
const cancelled: PasskeyCredentials = {
create: async () => null,
get: async () => null,
}
await expect(registerPasskey(LINKING_KEY, {credentials: cancelled})).rejects.toThrow(
'cancelled',
)
expect(hasPasskeySlots()).toBe(false)
})
it('throws before any ceremony when no passkeys are registered', async () => {
const auth = new FakeAuthenticator()
await expect(unlockWithPasskey({credentials: auth})).rejects.toThrow('No passkeys')
expect(auth.getCalls).toBe(0)
})
it('rejects unlock when the passkey returns no PRF secret', async () => {
const auth = new FakeAuthenticator()
await registerPasskey(LINKING_KEY, {credentials: auth})
auth.prfResultsOnGet = false
await expect(unlockWithPasskey({credentials: auth})).rejects.toThrow('PRF secret')
})
it('rejects unlock when the ceremony yields an unregistered credential', async () => {
const auth = new FakeAuthenticator()
await registerPasskey(LINKING_KEY, {credentials: auth})
const rogue: PasskeyCredentials = {
create: async () => null,
get: async () => ({
type: 'public-key',
rawId: crypto.getRandomValues(new Uint8Array(16)),
getClientExtensionResults: () => ({
prf: {enabled: true, results: {first: new Uint8Array(32)}},
}),
}),
}
await expect(unlockWithPasskey({credentials: rogue})).rejects.toThrow('not registered')
})
it('rejects unlock after the authenticator secret changed underneath the slot', async () => {
const auth = new FakeAuthenticator()
const slot = await registerPasskey(LINKING_KEY, {credentials: auth})
auth.rotateSecret(slot.credentialId)
await expect(unlockWithPasskey({credentials: auth})).rejects.toThrow()
})
})