Files
grateful-journal/src/__tests__/crypto.test.ts
2026-03-24 10:48:20 +05:30

285 lines
11 KiB
TypeScript

/**
* Tests for client-side encryption utilities (src/lib/crypto.ts)
*
* Uses a self-consistent XOR-based sodium mock so tests run without
* WebAssembly (libsodium) in the Node/happy-dom environment.
* The real PBKDF2 key derivation (Web Crypto API) is tested as-is.
*/
import { describe, it, expect, vi, beforeEach } from 'vitest'
import {
deriveSecretKey,
generateDeviceKey,
encryptEntry,
decryptEntry,
encryptSecretKey,
decryptSecretKey,
generateSalt,
getSalt,
saveSalt,
saveDeviceKey,
getDeviceKey,
clearDeviceKey,
} from '../lib/crypto'
// ---------------------------------------------------------------------------
// Self-consistent sodium mock (XOR cipher + 16-byte auth tag)
// encrypt(msg, key) = tag(16 zeros) || xor(msg, key)
// decrypt(ct, key) = xor(ct[16:], key)
// Wrong-key behavior is tested by overriding crypto_secretbox_open_easy to throw.
// ---------------------------------------------------------------------------
function xorBytes(data: Uint8Array, key: Uint8Array): Uint8Array {
return data.map((byte, i) => byte ^ key[i % key.length])
}
const createMockSodium = (overrides: Record<string, unknown> = {}) => ({
randombytes_buf: (size: number) => new Uint8Array(size).fill(42),
crypto_secretbox_NONCEBYTES: 24,
crypto_secretbox_easy: (msg: Uint8Array, _nonce: Uint8Array, key: Uint8Array) => {
const tag = new Uint8Array(16)
const encrypted = xorBytes(msg, key)
const result = new Uint8Array(tag.length + encrypted.length)
result.set(tag)
result.set(encrypted, tag.length)
return result
},
crypto_secretbox_open_easy: (ct: Uint8Array, _nonce: Uint8Array, key: Uint8Array) => {
if (ct.length < 16) throw new Error('invalid ciphertext length')
return xorBytes(ct.slice(16), key)
},
to_base64: (data: Uint8Array) => Buffer.from(data).toString('base64'),
from_base64: (str: string) => new Uint8Array(Buffer.from(str, 'base64')),
from_string: (str: string) => new TextEncoder().encode(str),
to_string: (data: Uint8Array) => new TextDecoder().decode(data),
...overrides,
})
vi.mock('../utils/sodium', () => ({
getSodium: vi.fn(),
}))
// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------
describe('crypto utilities', () => {
beforeEach(async () => {
const { getSodium } = await import('../utils/sodium')
vi.mocked(getSodium).mockResolvedValue(createMockSodium() as never)
localStorage.clear()
})
// ── deriveSecretKey ──────────────────────────────────────────────────────
describe('deriveSecretKey', () => {
it('returns a 32-byte Uint8Array', async () => {
const key = await deriveSecretKey('test-uid-123', 'test-salt')
expect(key).toBeInstanceOf(Uint8Array)
expect(key.length).toBe(32)
})
it('is deterministic — same inputs always produce the same key', async () => {
const key1 = await deriveSecretKey('uid-abc', 'salt-xyz')
const key2 = await deriveSecretKey('uid-abc', 'salt-xyz')
expect(key1).toEqual(key2)
})
it('different UIDs produce different keys', async () => {
const key1 = await deriveSecretKey('uid-1', 'same-salt')
const key2 = await deriveSecretKey('uid-2', 'same-salt')
expect(key1).not.toEqual(key2)
})
it('different salts produce different keys', async () => {
const key1 = await deriveSecretKey('same-uid', 'salt-a')
const key2 = await deriveSecretKey('same-uid', 'salt-b')
expect(key1).not.toEqual(key2)
})
it('handles empty UID string', async () => {
const key = await deriveSecretKey('', 'some-salt')
expect(key).toBeInstanceOf(Uint8Array)
expect(key.length).toBe(32)
})
})
// ── generateDeviceKey ────────────────────────────────────────────────────
describe('generateDeviceKey', () => {
it('returns a 32-byte Uint8Array', async () => {
const key = await generateDeviceKey()
expect(key).toBeInstanceOf(Uint8Array)
expect(key.length).toBe(32)
})
it('generates unique keys each time (random)', async () => {
const key1 = await generateDeviceKey()
const key2 = await generateDeviceKey()
// Two random 256-bit arrays should be different
expect(key1).not.toEqual(key2)
})
})
// ── encryptEntry / decryptEntry ──────────────────────────────────────────
describe('encryptEntry / decryptEntry', () => {
const secretKey = new Uint8Array(32).fill(1)
it('roundtrip: decrypting an encrypted entry returns original content', async () => {
const content = 'Today I am grateful for my family.'
const { ciphertext, nonce } = await encryptEntry(content, secretKey)
const decrypted = await decryptEntry(ciphertext, nonce, secretKey)
expect(decrypted).toBe(content)
})
it('returns base64-encoded strings for ciphertext and nonce', async () => {
const { ciphertext, nonce } = await encryptEntry('test content', secretKey)
expect(() => Buffer.from(ciphertext, 'base64')).not.toThrow()
expect(() => Buffer.from(nonce, 'base64')).not.toThrow()
// Valid base64 only contains these characters
expect(ciphertext).toMatch(/^[A-Za-z0-9+/=]+$/)
})
it('handles empty string content', async () => {
const { ciphertext, nonce } = await encryptEntry('', secretKey)
const decrypted = await decryptEntry(ciphertext, nonce, secretKey)
expect(decrypted).toBe('')
})
it('handles unicode and emoji content', async () => {
const content = 'Grateful for 🌟 life! नमस्ते 日本語'
const { ciphertext, nonce } = await encryptEntry(content, secretKey)
const decrypted = await decryptEntry(ciphertext, nonce, secretKey)
expect(decrypted).toBe(content)
})
it('handles very long content (10,000 chars)', async () => {
const content = 'a'.repeat(10000)
const { ciphertext, nonce } = await encryptEntry(content, secretKey)
const decrypted = await decryptEntry(ciphertext, nonce, secretKey)
expect(decrypted).toBe(content)
})
it('different plaintext produces different ciphertext', async () => {
const { ciphertext: ct1 } = await encryptEntry('hello world', secretKey)
const { ciphertext: ct2 } = await encryptEntry('goodbye world', secretKey)
expect(ct1).not.toBe(ct2)
})
it('decryptEntry throws "Failed to decrypt entry" on bad ciphertext', async () => {
const { getSodium } = await import('../utils/sodium')
vi.mocked(getSodium).mockResolvedValueOnce(createMockSodium({
crypto_secretbox_open_easy: () => { throw new Error('invalid mac') },
}) as never)
await expect(decryptEntry('notvalidbase64!!', 'nonce', secretKey))
.rejects.toThrow('Failed to decrypt entry')
})
it('decryptEntry throws when called with wrong key', async () => {
// Simulate libsodium authentication failure with wrong key
const { getSodium } = await import('../utils/sodium')
vi.mocked(getSodium)
.mockResolvedValueOnce(createMockSodium() as never) // for encrypt
.mockResolvedValueOnce(createMockSodium({ // for decrypt (wrong key throws)
crypto_secretbox_open_easy: () => { throw new Error('incorrect key') },
}) as never)
const { ciphertext, nonce } = await encryptEntry('secret', secretKey)
const wrongKey = new Uint8Array(32).fill(99)
await expect(decryptEntry(ciphertext, nonce, wrongKey))
.rejects.toThrow('Failed to decrypt entry')
})
})
// ── encryptSecretKey / decryptSecretKey ──────────────────────────────────
describe('encryptSecretKey / decryptSecretKey', () => {
it('roundtrip: encrypts and decrypts master key back to original', async () => {
const masterKey = new Uint8Array(32).fill(99)
const deviceKey = new Uint8Array(32).fill(55)
const { ciphertext, nonce } = await encryptSecretKey(masterKey, deviceKey)
const decrypted = await decryptSecretKey(ciphertext, nonce, deviceKey)
expect(decrypted).toEqual(masterKey)
})
it('returns base64 strings', async () => {
const masterKey = new Uint8Array(32).fill(1)
const deviceKey = new Uint8Array(32).fill(2)
const { ciphertext, nonce } = await encryptSecretKey(masterKey, deviceKey)
expect(typeof ciphertext).toBe('string')
expect(typeof nonce).toBe('string')
})
it('decryptSecretKey throws "Failed to decrypt secret key" on wrong device key', async () => {
const { getSodium } = await import('../utils/sodium')
vi.mocked(getSodium).mockResolvedValueOnce(createMockSodium({
crypto_secretbox_open_easy: () => { throw new Error('decryption failed') },
}) as never)
await expect(decryptSecretKey('fakeciphertext', 'fakenonce', new Uint8Array(32)))
.rejects.toThrow('Failed to decrypt secret key')
})
})
// ── salt functions ───────────────────────────────────────────────────────
describe('generateSalt / saveSalt / getSalt', () => {
it('generateSalt returns the constant salt string', () => {
expect(generateSalt()).toBe('grateful-journal-v1')
})
it('generateSalt is idempotent', () => {
expect(generateSalt()).toBe(generateSalt())
})
it('saveSalt and getSalt roundtrip', () => {
saveSalt('my-custom-salt')
expect(getSalt()).toBe('my-custom-salt')
})
it('getSalt returns null when nothing stored', () => {
localStorage.clear()
expect(getSalt()).toBeNull()
})
it('overwriting salt replaces old value', () => {
saveSalt('first')
saveSalt('second')
expect(getSalt()).toBe('second')
})
})
// ── device key localStorage ──────────────────────────────────────────────
describe('saveDeviceKey / getDeviceKey / clearDeviceKey', () => {
it('saves and retrieves device key correctly', async () => {
const key = new Uint8Array(32).fill(7)
await saveDeviceKey(key)
const retrieved = await getDeviceKey()
expect(retrieved).toEqual(key)
})
it('returns null when no device key is stored', async () => {
localStorage.clear()
const key = await getDeviceKey()
expect(key).toBeNull()
})
it('clearDeviceKey removes the stored key', async () => {
const key = new Uint8Array(32).fill(7)
await saveDeviceKey(key)
clearDeviceKey()
const retrieved = await getDeviceKey()
expect(retrieved).toBeNull()
})
it('overwriting device key stores the new key', async () => {
const key1 = new Uint8Array(32).fill(1)
const key2 = new Uint8Array(32).fill(2)
await saveDeviceKey(key1)
await saveDeviceKey(key2)
const retrieved = await getDeviceKey()
expect(retrieved).toEqual(key2)
})
})
})