diff options
6 files changed, 272 insertions, 21 deletions
diff --git a/packages/meshbay-hub/src/meshbay_hub/api/users.py b/packages/meshbay-hub/src/meshbay_hub/api/users.py index 8e780df..fb53076 100644 --- a/packages/meshbay-hub/src/meshbay_hub/api/users.py +++ b/packages/meshbay-hub/src/meshbay_hub/api/users.py @@ -1,6 +1,7 @@ """User endpoints — /v1/users/*""" import base64 +import hashlib import logging import re import secrets @@ -42,6 +43,7 @@ from meshbay_hub.db.models import ( GroupInviteLink, GroupMember, IPLog, + KnownBrowser, Node, Notification, RefreshToken, @@ -161,6 +163,7 @@ class LoginRequest(BaseModel): username: str password: str | None = None # legacy (raw password) for migration auth_key: str | None = None # PBKDF2-derived auth key (new scheme) + known_browser: str | None = None # from an earlier sign-in on this browser class RefreshRequest(BaseModel): @@ -351,6 +354,58 @@ async def _take_login_attempt(db: AsyncSession, username: str) -> None: headers={"Retry-After": str(retry_after)}) +def _session_counter(user: User) -> str: + """The failure counter for a passphrase re-checked inside an open session. + + Its own, not the sign-in one: a stranger who keeps a name locked at sign-in + must not also stop its owner changing their passphrase, deleting their + account or registering a device from a session they already hold. + """ + return f"\x00session:{user.id}" + + +async def _browser_counter(db: AsyncSession, username: str, + token: str | None) -> tuple[str, "KnownBrowser | None"]: + """The failure counter for a sign-in, and the known browser behind it if any. + + A browser that signed in to this account before presents its token and is + counted on its own: the username's counter, which anyone can spend, then + locks only browsers this account has never used. A token for another + account, or none, is the username's counter — the answer is the same either + way, so it says nothing about the account (M1). + """ + if token: + row = (await db.execute( + select(KnownBrowser).join(User, User.id == KnownBrowser.user_id) + .where(KnownBrowser.token_hash == _browser_hash(token), + User.username == username))).scalar_one_or_none() + if row is not None: + return f"{username}\x00browser:{row.id}", row + return username, None + + +def _browser_hash(token: str) -> str: + return hashlib.sha256(f"meshbay:known_browser:{token}".encode()).hexdigest() + + +# How many browsers one account is remembered on. The oldest goes first; a +# browser forgotten here is only an unknown one again. +MAX_KNOWN_BROWSERS = 20 + + +async def _remember_browser(db: AsyncSession, user: User) -> str: + """A new known-browser token for `user`. The caller commits.""" + raw = secrets.token_urlsafe(32) + rows = (await db.execute( + select(KnownBrowser.id).where(KnownBrowser.user_id == user.id) + .order_by(KnownBrowser.last_used_at.desc()))).scalars().all() + stale = rows[MAX_KNOWN_BROWSERS - 1:] + if stale: + await db.execute(delete(KnownBrowser).where(KnownBrowser.id.in_(stale))) + db.add(KnownBrowser(user_id=user.id, token_hash=_browser_hash(raw))) + return raw + + async def _prove_passphrase(db: AsyncSession, user: User, auth_key: str) -> None: """Refuse with 403 unless `auth_key` is this account's, spending an attempt. @@ -358,18 +413,18 @@ async def _prove_passphrase(db: AsyncSession, user: User, auth_key: str) -> None refreshed one, or one lifted from a page, and what it would buy here outlives the session or reopens the offline search the pepper exists to prevent. """ - await _take_login_attempt(db, user.username) + await _take_login_attempt(db, _session_counter(user)) if not await verify_password_off_loop(auth_key, user.pw_hash, user.pw_salt, user.pw_version): raise HTTPException(status_code=403, detail="Passphrase does not match") - await login_throttle.clear(db, user.username) + await login_throttle.clear(db, _session_counter(user)) async def _login_failed(db: AsyncSession, username: str, ip: str, - user_id: str | None = None) -> None: + user_id: str | None = None, counter: str | None = None) -> None: """Record a wrong passphrase and answer 401. Always raises.""" db.add(IPLog(user_id=user_id, event="login_fail", ip_address=ip, detail=username)) - if await login_throttle.is_now_locked(db, username): + if await login_throttle.is_now_locked(db, counter or username): # Once, on the failure that spent the last attempt — so the logs tab # shows when a name was locked, not every refusal after it. db.add(IPLog(user_id=user_id, event="login_locked", ip_address=ip, @@ -431,32 +486,33 @@ async def login( # Before the account is even looked up: an unknown name spends attempts and # locks exactly like a real one, so neither answer tells them apart (M1). - await _take_login_attempt(db, body.username) + counter, browser = await _browser_counter(db, body.username, body.known_browser) + await _take_login_attempt(db, counter) result = await db.execute( select(User).where(User.username == body.username)) user = result.scalar_one_or_none() if not user: - await _login_failed(db, body.username, ip) + await _login_failed(db, body.username, ip, counter=counter) if user.pw_version >= 3: # New scheme: verify auth_key if not body.auth_key or not await verify_password_off_loop( body.auth_key, user.pw_hash, user.pw_salt, version=user.pw_version ): - await _login_failed(db, body.username, ip, user.id) + await _login_failed(db, body.username, ip, user.id, counter) else: # Legacy scheme: need raw password if not body.password: # Nothing was checked, so nothing was guessed. - await login_throttle.release(db, body.username) + await login_throttle.release(db, counter) await db.commit() raise HTTPException(status_code=401, detail="auth_upgrade_required") if not await verify_password_off_loop( body.password, user.pw_hash, user.pw_salt, version=user.pw_version ): - await _login_failed(db, body.username, ip, user.id) + await _login_failed(db, body.username, ip, user.id, counter) # Migrate to new scheme if auth_key provided alongside password if body.auth_key: new_hash, new_salt = await hash_password_off_loop(body.auth_key) @@ -471,6 +527,7 @@ async def login( user.pw_version = 2 # The passphrase was right, whatever the account's status turns out to be. + await login_throttle.clear(db, counter) await login_throttle.clear(db, body.username) if user.status != "active": @@ -501,6 +558,11 @@ async def login( )) db.add(IPLog(user_id=user.id, event="login", ip_address=ip)) pepper = _bundle_pepper(user) + if browser is not None: + browser.last_used_at = datetime.now(UTC) + known = {} + else: + known = {"known_browser": await _remember_browser(db, user)} await db.commit() return { @@ -509,6 +571,7 @@ async def login( "token_type": "bearer", "expires_in": _ttl(), **pepper, + **known, } @@ -787,7 +850,8 @@ async def get_current_user_info( # A passphrase change re-wraps every node's bundle *before* the hub # accepts the new passphrase, and must not start while the hub would # then refuse it. - "passphrase_locked_for": await login_throttle.locked_for(db, current_user.username), + "passphrase_locked_for": await login_throttle.locked_for( + db, _session_counter(current_user)), } @@ -849,13 +913,13 @@ async def update_profile( raise HTTPException( status_code=403, detail="Changing your e-mail requires your passphrase.") - await _take_login_attempt(db, current_user.username) + await _take_login_attempt(db, _session_counter(current_user)) if not await verify_password_off_loop( body.auth_key, current_user.pw_hash, current_user.pw_salt, current_user.pw_version): raise HTTPException(status_code=403, detail="Passphrase does not match") - await login_throttle.clear(db, current_user.username) + await login_throttle.clear(db, _session_counter(current_user)) # How often one account may point the hub at a *different* address. # Long, because this is the only path where a signed-in account chooses @@ -1074,12 +1138,12 @@ async def change_password( current_user: User = Depends(require_user_scope), db: AsyncSession = Depends(get_db), ): - await _take_login_attempt(db, current_user.username) + await _take_login_attempt(db, _session_counter(current_user)) if not await verify_password_off_loop(body.old_auth_key, current_user.pw_hash, current_user.pw_salt, current_user.pw_version): raise HTTPException(status_code=403, detail="Current passphrase does not match") - await login_throttle.clear(db, current_user.username) + await login_throttle.clear(db, _session_counter(current_user)) if body.new_auth_key == body.old_auth_key: raise HTTPException(status_code=400, detail="New passphrase must differ from the current one") @@ -1279,6 +1343,7 @@ async def password_reset( update(RefreshToken).where(RefreshToken.user_id == user.id) .values(revoked=True)) await db.execute(delete(UserDevice).where(UserDevice.user_id == user.id)) + await db.execute(delete(KnownBrowser).where(KnownBrowser.user_id == user.id)) # A code sent to the address on file is a stronger proof than a passphrase, # and it is the way out of a lockout somebody else caused. await login_throttle.clear(db, user.username) @@ -1493,6 +1558,7 @@ async def erase_account(db: AsyncSession, user: User, owned_groups: str = "refus GroupHost.node_id.in_(select(Node.id).where(Node.user_id == user.id)))) await db.execute(delete(Node).where(Node.user_id == user.id)) await db.execute(delete(UserDevice).where(UserDevice.user_id == user.id)) + await db.execute(delete(KnownBrowser).where(KnownBrowser.user_id == user.id)) await db.execute(delete(EmailVerification).where(EmailVerification.user_id == user.id)) # Links this account issued for a group it no longer owns; the ones for its # own groups went with them above. A used link keeps pointing at the @@ -1538,11 +1604,11 @@ async def delete_own_account( borrowed laptop or a session left open. Same value as at sign-in, so the hub still never sees the passphrase itself. """ - await _take_login_attempt(db, current_user.username) + await _take_login_attempt(db, _session_counter(current_user)) if not await verify_password_off_loop(body.auth_key, current_user.pw_hash, current_user.pw_salt, current_user.pw_version): raise HTTPException(status_code=403, detail="Passphrase does not match") - await login_throttle.clear(db, current_user.username) + await login_throttle.clear(db, _session_counter(current_user)) return await erase_account(db, current_user) diff --git a/packages/meshbay-hub/src/meshbay_hub/db/migrations/versions/d4e5f6a7b8ca_known_browsers.py b/packages/meshbay-hub/src/meshbay_hub/db/migrations/versions/d4e5f6a7b8ca_known_browsers.py new file mode 100644 index 0000000..aaad5c7 --- /dev/null +++ b/packages/meshbay-hub/src/meshbay_hub/db/migrations/versions/d4e5f6a7b8ca_known_browsers.py @@ -0,0 +1,32 @@ +"""browsers an account has signed in from, each with its own failure counter + +Revision ID: d4e5f6a7b8ca +Revises: c3d4e5f6a7b9 +""" + +from collections.abc import Sequence + +import sqlalchemy as sa +from alembic import op + +revision: str = "d4e5f6a7b8ca" +down_revision: str | Sequence[str] | None = "c3d4e5f6a7b9" +branch_labels: str | Sequence[str] | None = None +depends_on: str | Sequence[str] | None = None + + +def upgrade() -> None: + op.create_table( + "known_browsers", + sa.Column("id", sa.String(36), primary_key=True), + sa.Column("user_id", sa.String(36), sa.ForeignKey("users.id"), nullable=False), + sa.Column("token_hash", sa.String(64), nullable=False, unique=True), + sa.Column("created_at", sa.DateTime(timezone=True)), + sa.Column("last_used_at", sa.DateTime(timezone=True)), + ) + op.create_index("ix_known_browsers_user_id", "known_browsers", ["user_id"]) + + +def downgrade() -> None: + op.drop_index("ix_known_browsers_user_id", table_name="known_browsers") + op.drop_table("known_browsers") diff --git a/packages/meshbay-hub/src/meshbay_hub/db/models.py b/packages/meshbay-hub/src/meshbay_hub/db/models.py index 1e652a6..dbc0f10 100644 --- a/packages/meshbay-hub/src/meshbay_hub/db/models.py +++ b/packages/meshbay-hub/src/meshbay_hub/db/models.py @@ -429,6 +429,25 @@ class MailQuota(Base): last_sent: Mapped[datetime | None] = mapped_column(DateTime(timezone=True)) +class KnownBrowser(Base): + """A browser this account has signed in from, for the sign-in lockout. + + Its own failure counter, which a stranger cannot spend: the lockout keyed by + username alone let anyone who knew a name keep its owner out of every + browser, four requests an hour. Only a hash of the token is kept. It is not + a credential — a sign-in presenting it still needs the passphrase. + """ + + __tablename__ = "known_browsers" + + id: Mapped[str] = mapped_column(String(36), primary_key=True, default=_uuid) + user_id: Mapped[str] = mapped_column(ForeignKey("users.id"), nullable=False, + index=True) + token_hash: Mapped[str] = mapped_column(String(64), unique=True, nullable=False) + created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_now) + last_used_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=_now) + + class LoginThrottle(Base): """Wrong passphrases per username, for the sign-in lockout (`login_throttle.py`). diff --git a/packages/meshbay-hub/src/meshbay_hub/static/keyderive.js b/packages/meshbay-hub/src/meshbay_hub/static/keyderive.js index 6bd5896..b1770a7 100644 --- a/packages/meshbay-hub/src/meshbay_hub/static/keyderive.js +++ b/packages/meshbay-hub/src/meshbay_hub/static/keyderive.js @@ -426,13 +426,36 @@ async function decryptBundle(bundleB64, aesKey, { userId, nodePk }) { * decrypts it and returns the keys + encrypted bundle for push to node. * Otherwise returns bundleKey so the caller can fetch from node during handshake. */ +// The token the hub gave this browser at an earlier sign-in, per account. It +// is not a credential — the passphrase is still asked — but a sign-in that +// presents it has a failure counter of its own, so a stranger who keeps +// failing on this account's name locks only browsers it has never used. +// Kept across sign-outs on purpose: forgetting it would be the lockout again. +const KNOWN_BROWSERS = 'mb_known_browsers'; + +function _knownBrowser(username) { + try { return (JSON.parse(localStorage.getItem(KNOWN_BROWSERS)) || {})[username] || null; } + catch { return null; } +} + +function _rememberBrowser(username, token) { + if (!token) return; + try { + const all = JSON.parse(localStorage.getItem(KNOWN_BROWSERS)) || {}; + all[username] = token; + localStorage.setItem(KNOWN_BROWSERS, JSON.stringify(all)); + } catch { /* storage refused: this browser stays an unknown one */ } +} + async function loginAndRecover(username, password) { const authKey = await deriveAuthKey(password, username); + const known = _knownBrowser(username); const resp = await hubCall('/v1/users/login', { method: 'POST', headers: { 'Content-Type': 'application/json' }, - body: JSON.stringify({ username, auth_key: authKey }), + body: JSON.stringify({ username, auth_key: authKey, + ...(known ? { known_browser: known } : {}) }), }); if (!resp.ok) { @@ -454,6 +477,7 @@ async function loginAndRecover(username, password) { } const data = await resp.json(); + _rememberBrowser(username, data.known_browser); const result = { accessToken: data.access_token, refreshToken: data.refresh_token, diff --git a/packages/meshbay-hub/tests/test_known_browser.py b/packages/meshbay-hub/tests/test_known_browser.py new file mode 100644 index 0000000..260f08e --- /dev/null +++ b/packages/meshbay-hub/tests/test_known_browser.py @@ -0,0 +1,98 @@ +""" +A stranger who knows your name locks only the browsers you never used. + +The sign-in lockout counts wrong passphrases per username: four an hour from +anyone kept the owner out of every browser for as long as they cared to keep +going. A browser that signed in to the account before presents a token and has +a counter of its own, which nobody else can spend. The token is not a +credential — the passphrase is still asked — and a passphrase re-checked inside +an open session is not the sign-in counter's business at all. +""" + +import pytest +from meshbay_hub.db.models import KnownBrowser, User +from sqlalchemy import func, select +from test_bundle_pepper import KEY, _register + +WRONG = "w" * 44 + + +async def _sign_in(client, username, key=KEY, known=None): + body = {"username": username, "auth_key": key} + if known: + body["known_browser"] = known + return await client.post("/v1/users/login", json=body) + + +async def _lock(client, username): + for _ in range(4): + await _sign_in(client, username, WRONG) + assert (await _sign_in(client, username)).status_code == 429 + + +@pytest.mark.asyncio +async def test_a_known_browser_signs_in_through_a_strangers_lockout(client): + await _register(client, "known_owner") + token = (await _sign_in(client, "known_owner")).json()["known_browser"] + + await _lock(client, "known_owner") # the stranger, without a token + r = await _sign_in(client, "known_owner", known=token) + assert r.status_code == 200, r.text + assert "known_browser" not in r.json(), "a known browser is not given a second token" + + +@pytest.mark.asyncio +async def test_another_accounts_token_is_no_way_round(client): + await _register(client, "known_alice") + await _register(client, "known_bobby") + alices = (await _sign_in(client, "known_alice")).json()["known_browser"] + + await _lock(client, "known_bobby") + assert (await _sign_in(client, "known_bobby", known=alices)).status_code == 429 + + +@pytest.mark.asyncio +async def test_a_known_browser_is_locked_by_its_own_failures(client): + """Whoever holds the token still guesses at the same rate.""" + await _register(client, "known_guess") + token = (await _sign_in(client, "known_guess")).json()["known_browser"] + for _ in range(4): + assert (await _sign_in(client, "known_guess", WRONG, token)).status_code == 401 + assert (await _sign_in(client, "known_guess", known=token)).status_code == 429 + # ...and that spent nothing of a browser that has no token. + assert (await _sign_in(client, "known_guess")).status_code == 200 + + +@pytest.mark.asyncio +async def test_a_locked_name_does_not_stop_its_owner_inside_a_session(client): + await _register(client, "known_inside") + session = (await _sign_in(client, "known_inside")).json()["access_token"] + await _lock(client, "known_inside") + + r = await client.post("/v1/users/me/bundle-pepper", json={"auth_key": KEY}, + headers={"Authorization": f"Bearer {session}"}) + assert r.status_code == 200, r.text + + +@pytest.mark.asyncio +async def test_only_a_hash_is_kept_and_only_twenty(client, db_session): + await _register(client, "known_many") + tokens = [(await _sign_in(client, "known_many")).json()["known_browser"] + for _ in range(25)] + uid = (await db_session.execute( + select(User.id).where(User.username == "known_many"))).scalar_one() + rows = (await db_session.execute( + select(KnownBrowser).where(KnownBrowser.user_id == uid))).scalars().all() + assert len(rows) == 20 + assert not any(t in {r.token_hash for r in rows} for t in tokens) + + +@pytest.mark.asyncio +async def test_erasing_the_account_forgets_its_browsers(client, db_session): + await _register(client, "known_gone") + login = (await _sign_in(client, "known_gone")).json() + r = await client.request("DELETE", "/v1/users/me", json={"auth_key": KEY}, + headers={"Authorization": f"Bearer {login['access_token']}"}) + assert r.status_code == 200, r.text + left = await db_session.scalar(select(func.count()).select_from(KnownBrowser)) + assert left == 0 diff --git a/packages/meshbay-hub/tests/test_login_lockout.py b/packages/meshbay-hub/tests/test_login_lockout.py index 601edbd..8f06d2d 100644 --- a/packages/meshbay-hub/tests/test_login_lockout.py +++ b/packages/meshbay-hub/tests/test_login_lockout.py @@ -131,8 +131,13 @@ async def test_a_burst_of_concurrent_guesses_gets_no_more_than_the_limit(client) @pytest.mark.asyncio -async def test_change_password_counts_on_the_same_row(client): - """It checks the same passphrase, so it is the same oracle.""" +async def test_change_password_counts_on_the_sessions_own_row(client): + """ + It checks the passphrase, so it is counted and locked like a sign-in — on a + row of the session's own. A stranger failing at sign-in must not stop the + owner changing their passphrase from a session they hold, and failures here + must not lock the owner's other browsers out of signing in. + """ await _register(client, "grace_test") token = (await _login(client, "grace_test", RIGHT)).json()["access_token"] auth = {"Authorization": f"Bearer {token}"} @@ -145,7 +150,7 @@ async def test_change_password_counts_on_the_same_row(client): r = await client.post("/v1/users/password", headers=auth, json={ "old_auth_key": RIGHT, "new_auth_key": "n" * 44}) assert r.status_code == 429, r.text - assert (await _login(client, "grace_test", RIGHT)).status_code == 429 + assert (await _login(client, "grace_test", RIGHT)).status_code == 200 @pytest.mark.asyncio @@ -157,10 +162,17 @@ async def test_a_signed_in_session_is_told_its_own_lockout(client): auth = {"Authorization": f"Bearer {token}"} assert (await client.get("/v1/users/me", headers=auth)).json()["passphrase_locked_for"] == 0 - await _fail(client, "olivia_test", 4) + for _ in range(4): + await client.post("/v1/users/password", headers=auth, json={ + "old_auth_key": WRONG, "new_auth_key": "n" * 44}) left = (await client.get("/v1/users/me", headers=auth)).json()["passphrase_locked_for"] assert 3500 <= left <= 3600 + # A stranger failing at sign-in is not this session's lockout. + await _fail(client, "olivia_test", 4) + other = (await _login(client, "olivia_test", RIGHT)) + assert other.status_code == 429 + @pytest.mark.asyncio async def test_an_attempt_that_checks_no_passphrase_is_not_counted(client, db_session): |