// Author:  cirakg & claude ai
// Summary: Tests for PINs: create, unlock, wrong PIN, the lockout schedule on a fake clock, erase, change, reset, auto-lock.

import Toybox.Lang;
import Toybox.Test;

(:test)
function pinCreateUnlockAndWrongPin(logger as Test.Logger) as Boolean {
    var store = new MemoryBackend();
    var vault = new Vault(store, new FakeTime());
    if (vault.hasPin() || vault.session.isUnlocked()) {
        logger.error("fresh vault state wrong");
        return false;
    }
    StorageFixtures.setPin(vault, StorageFixtures.PIN);
    if (!vault.hasPin() || !vault.session.isUnlocked()) {
        logger.error("setting the first PIN should leave the session unlocked");
        return false;
    }
    vault.lock();
    // A new Vault (app restart) on the same store.
    var reopened = new Vault(store, new FakeTime());
    var wrong = StorageFixtures.unlock(reopened, StorageFixtures.OTHER_PIN);
    var failuresAfterWrong = reopened.lockout.failures();
    var right = StorageFixtures.unlock(reopened, StorageFixtures.PIN);
    return !wrong && failuresAfterWrong == 1 && right && reopened.session.isUnlocked()
        && reopened.lockout.failures() == 0 && store.getValue(Lockout.STORAGE_KEY) == null;
}

(:test)
function pinRejectsMalformedPins(logger as Test.Logger) as Boolean {
    var bad = ["123", "12345678901", "12a4", ""];
    for (var i = 0; i < bad.size(); i++) {
        if (KeyManager.isValidPin(Bytes.fromUtf8(bad[i]))) {
            logger.error("accepted PIN '" + bad[i] + "'");
            return false;
        }
    }
    return KeyManager.isValidPin(Bytes.fromUtf8("0000")) && KeyManager.isValidPin(Bytes.fromUtf8("0123456789"));
}

(:test)
function lockoutDelaySchedule(logger as Test.Logger) as Boolean {
    var expected = [0, 0, 0, 0, 0, 30, 60, 120, 240, 480, 960, 1920, 3600, 3600, 3600];
    for (var f = 0; f < expected.size(); f++) {
        if (Lockout.delayFor(f) != expected[f]) {
            logger.error("delay after " + f + " failures: " + Lockout.delayFor(f));
            return false;
        }
    }
    return Lockout.delayFor(1000) == Lockout.MAX_DELAY_S;
}

// Four free attempts, then the 5th failure starts a 30 s wait; an attempt
// during the wait is refused without being counted; the wait survives an
// app restart.
(:test)
function lockoutBlocksAndSurvivesRestart(logger as Test.Logger) as Boolean {
    var store = new MemoryBackend();
    var time = new FakeTime();
    var vault = new Vault(store, time);
    StorageFixtures.setPin(vault, StorageFixtures.PIN);
    vault.lock();
    for (var i = 0; i < 5; i++) {
        if (StorageFixtures.unlock(vault, StorageFixtures.OTHER_PIN)) {
            return false;
        }
    }
    if (vault.lockout.remainingSeconds() != 30) {
        logger.error("expected 30 s after 5 failures, got " + vault.lockout.remainingSeconds());
        return false;
    }
    var refused = 0;
    try {
        vault.beginUnlock(StorageFixtures.pin(StorageFixtures.PIN));
    } catch (err instanceof VaultError) {
        refused = err.code;
    }
    time.advance(10);
    var restarted = new Vault(store, time);
    var remainingAfterRestart = restarted.lockout.remainingSeconds();
    time.advance(20);
    var openAgain = restarted.lockout.remainingSeconds() == 0;
    var right = StorageFixtures.unlock(restarted, StorageFixtures.PIN);
    return refused == VaultError.LOCKED_OUT && restarted.lockout.failures() == 0 && remainingAfterRestart == 20
        && openAgain && right;
}

// Without a synced trusted clock the delay counts uptime and restarts in
// full when the app restarts (never shorter, sometimes longer).
(:test)
function lockoutUsesUptimeWithoutTrustedClock(logger as Test.Logger) as Boolean {
    var store = new MemoryBackend();
    var time = new FakeTime();
    time.trusted = null;
    var vault = new Vault(store, time);
    StorageFixtures.setPin(vault, StorageFixtures.PIN);
    vault.lock();
    for (var i = 0; i < 6; i++) {
        StorageFixtures.unlock(vault, StorageFixtures.OTHER_PIN);
        time.advance(Lockout.MAX_DELAY_S);
    }
    // 6 failures: 60 s delay, which has passed on the uptime clock above.
    StorageFixtures.unlock(vault, StorageFixtures.OTHER_PIN); // 7th failure: 120 s
    time.advance(100);
    var before = vault.lockout.remainingSeconds();
    var restarted = new Vault(store, time);
    var after = restarted.lockout.remainingSeconds();
    // A system timer that goes backwards (watch restart) also restarts the delay.
    time.uptime = 5;
    var afterReboot = restarted.lockout.remainingSeconds();
    return before == 20 && after == 120 && afterReboot == 120;
}

// A damaged lockout record must not reset the count.
(:test)
function lockoutTreatsDamagedStateConservatively(logger as Test.Logger) as Boolean {
    var store = new MemoryBackend();
    store.setValue(Lockout.STORAGE_KEY, {"f" => "garbage"});
    var lockout = new Lockout(store, new FakeTime());
    return lockout.failures() == Lockout.FREE_ATTEMPTS && Lockout.delayFor(lockout.failures() + 1) == Lockout.BASE_DELAY_S;
}

(:test)
function pinEraseAfterTenFailures(logger as Test.Logger) as Boolean {
    var store = new MemoryBackend();
    var time = new FakeTime();
    var vault = new Vault(store, time);
    vault.eraseAfterFailures = true;
    StorageFixtures.setPin(vault, StorageFixtures.PIN);
    var open = vault.add(StorageFixtures.totp("Unlocked"));
    var locked = StorageFixtures.totp("Locked");
    locked.locked = true;
    var lockedId = vault.add(locked);
    vault.lock();
    var pending = StorageFixtures.code("Pending");
    pending.locked = true;
    vault.add(pending);
    for (var i = 0; i < Lockout.ERASE_AFTER; i++) {
        if (i == Lockout.ERASE_AFTER - 1 && (!vault.hasPin() || vault.ids().size() != 2)) {
            logger.error("erased too early");
            return false;
        }
        StorageFixtures.unlock(vault, StorageFixtures.OTHER_PIN);
        time.advance(Lockout.MAX_DELAY_S);
    }
    var ids = vault.ids();
    return !vault.hasPin() && ids.size() == 1 && ids[0].equals(open) && vault.pendingIds().size() == 0
        && store.getValue("e." + lockedId) == null && vault.lockout.failures() == 0;
}

(:test)
function pinChangeKeepsEntries(logger as Test.Logger) as Boolean {
    var store = new MemoryBackend();
    var vault = new Vault(store, new FakeTime());
    StorageFixtures.setPin(vault, StorageFixtures.PIN);
    var e = StorageFixtures.totp("Locked");
    e.locked = true;
    var id = vault.add(e);
    var recordBefore = store.getValue("e." + id) as ByteArray;
    StorageFixtures.setPin(vault, StorageFixtures.OTHER_PIN); // while unlocked: re-wrap
    vault.lock();
    var oldPinFails = !StorageFixtures.unlock(vault, StorageFixtures.PIN);
    var newPinWorks = StorageFixtures.unlock(vault, StorageFixtures.OTHER_PIN);
    var opened = vault.open(id);
    var ok = StorageFixtures.same(logger, opened, e);
    opened.wipeSecrets();
    // Entries aren't re-encrypted by a PIN change.
    var unchanged = Bytes.equal(recordBefore, store.getValue("e." + id) as ByteArray);
    vault.lock();
    var lockedCode = 0;
    try {
        vault.beginSetPin(StorageFixtures.pin("999999"), StorageFixtures.ITERATIONS);
    } catch (err instanceof VaultError) {
        lockedCode = err.code;
    }
    return oldPinFails && newPinWorks && ok && unchanged && lockedCode == VaultError.LOCKED;
}

(:test)
function pinResetErasesOnlyLockedData(logger as Test.Logger) as Boolean {
    var store = new MemoryBackend();
    var vault = new Vault(store, new FakeTime());
    StorageFixtures.setPin(vault, StorageFixtures.PIN);
    var keep = vault.add(StorageFixtures.totp("Keep"));
    var gone = StorageFixtures.totp("Gone");
    gone.locked = true;
    vault.add(gone);
    vault.lock();
    vault.resetPin();
    StorageFixtures.setPin(vault, StorageFixtures.OTHER_PIN);
    var ids = vault.ids();
    var opened = vault.open(keep);
    opened.wipeSecrets();
    return ids.size() == 1 && ids[0].equals(keep) && vault.session.isUnlocked();
}

// A tampered iteration count or salt fails like a wrong PIN (or is refused
// before deriving when the count is out of range).
(:test)
function pinWrapIsAuthenticated(logger as Test.Logger) as Boolean {
    var store = new MemoryBackend();
    var vault = new Vault(store, new FakeTime());
    StorageFixtures.setPin(vault, StorageFixtures.PIN);
    vault.lock();
    var wrap = store.raw(KeyManager.WRAP_KEY) as ByteArray;
    wrap[0] = wrap[0] ^ 1; // salt
    var saltTampered = !StorageFixtures.unlock(vault, StorageFixtures.PIN);
    wrap[0] = wrap[0] ^ 1;
    wrap[KeyManager.SALT_BYTES] = 0x7F; // iteration count far above the maximum
    var code = 0;
    try {
        vault.beginUnlock(StorageFixtures.pin(StorageFixtures.PIN));
    } catch (err instanceof VaultError) {
        code = err.code;
    }
    return saltTampered && code == VaultError.DAMAGED;
}

(:test)
function sessionAutoLocksAndWipesKeys(logger as Test.Logger) as Boolean {
    var time = new FakeTime();
    var vault = new Vault(new MemoryBackend(), time);
    StorageFixtures.setPin(vault, StorageFixtures.PIN);
    var session = vault.session;
    var masterKey = session.masterKey();
    var keys = session.keys();
    session.autoLockMs = 30000;
    time.advance(29);
    var stillOpen = !session.checkExpiry();
    session.touch();
    time.advance(29);
    var stillOpenAfterTouch = !session.checkExpiry();
    time.advance(1);
    var lockedNow = session.checkExpiry();
    return stillOpen && stillOpenAfterTouch && lockedNow && !session.isUnlocked()
        && StorageFixtures.allZero(masterKey) && StorageFixtures.allZero(keys.encKey) && StorageFixtures.allZero(keys.macKey);
}

(:test)
function pinKeyBuffersAreWiped(logger as Test.Logger) as Boolean {
    var pbkdf2 = new Kdf.Pbkdf2(StorageFixtures.pin(StorageFixtures.PIN), new [16]b, StorageFixtures.ITERATIONS, KeyManager.KEY_BYTES);
    Jobs.runToCompletion(pbkdf2, Kdf.ITERATIONS_PER_STEP);
    var derived = !StorageFixtures.allZero(pbkdf2.result());
    pbkdf2.wipe();
    var wiped = StorageFixtures.allZero(pbkdf2.result());
    var keys = new SealedBox.Keys(new [32]b);
    keys.wipe();
    return derived && wiped && StorageFixtures.allZero(keys.encKey) && StorageFixtures.allZero(keys.macKey);
}

// The UI-test fixture's wrap was computed in Python (tools/gen_fixture_wrap.py);
// the app's unlock code must accept it with the fixture PIN and recover the
// fixture master key, which cross-checks the wrap format.
(:test)
function pinOpensThePythonComputedFixtureWrap(logger as Test.Logger) as Boolean {
    var store = new MemoryBackend();
    store.setValue(KeyManager.WRAP_KEY, Bytes.fromHex(Fixtures.FIXTURE_WRAP));
    var vault = new Vault(store, new FakeTime());
    var wrongRejected = !StorageFixtures.unlock(vault, StorageFixtures.OTHER_PIN);
    var opened = StorageFixtures.unlock(vault, Fixtures.FIXTURE_PIN);
    return wrongRejected && opened && Bytes.equal(vault.session.masterKey(), Bytes.fromHex(Fixtures.FIXTURE_MASTER_KEY));
}