diff options
5 files changed, 87 insertions, 13 deletions
diff --git a/packages/meshbay-common/src/meshbay_common/handshake.py b/packages/meshbay-common/src/meshbay_common/handshake.py index 73a2858..223f064 100644 --- a/packages/meshbay-common/src/meshbay_common/handshake.py +++ b/packages/meshbay-common/src/meshbay_common/handshake.py @@ -53,7 +53,17 @@ NONCE_LEN = 32 class HandshakeError(Exception): - """Refusal, with a message safe to hand to the peer.""" + """ + Refusal, with a message safe to hand to the peer. + + `code` is the same refusal in a form a client can act on. The text is for a + human and may be reworded; matching on it from the client would be a string + comparison that breaks silently the day someone improves the wording. + """ + + def __init__(self, message: str, code: str = ""): + super().__init__(message) + self.code = code class DenylistLike(Protocol): @@ -170,7 +180,11 @@ def authorize_token( raise HandshakeError("Token revoked") if group_id not in decoded.get("groups", []): - raise HandshakeError("Not a member of this group") + # Almost always a token issued before the person was added to the group: + # `groups` is baked in at login and the hub does not push updates. The + # client refreshes and retries on this code rather than telling someone + # who *is* a member that they are not one. + raise HandshakeError("Not a member of this group", code="not_a_member") if hosted_groups is not None and group_id not in hosted_groups: raise HandshakeError("Group not hosted on this node") diff --git a/packages/meshbay-common/tests/test_handshake.py b/packages/meshbay-common/tests/test_handshake.py index ba8788a..8981db8 100644 --- a/packages/meshbay-common/tests/test_handshake.py +++ b/packages/meshbay-common/tests/test_handshake.py @@ -197,3 +197,29 @@ def test_transcript_is_unambiguous(): def test_bindings_differ_by_transport(): """A WebRTC proof must not be replayable on a QUIC connection.""" assert webrtc_binding(b"\xaa" * 32, b"\xbb" * 32) != quic_binding(b"cert-der") + + +def test_membership_refusal_carries_a_code_a_client_can_act_on(): + """ + `groups` is baked into the token at login, so someone added to a group after + signing in is refused although they are a member. The client refreshes and + retries on this code — it must not have to match on the human wording, which + is exactly the kind of coupling that breaks when someone improves a message. + """ + import jwt as _jwt + from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey + from cryptography.hazmat.primitives import serialization + + sk = Ed25519PrivateKey.generate() + pem_priv = sk.private_bytes( + serialization.Encoding.PEM, serialization.PrivateFormat.PKCS8, + serialization.NoEncryption()) + pem_pub = sk.public_key().public_bytes( + serialization.Encoding.PEM, serialization.PublicFormat.SubjectPublicKeyInfo) + + token = _jwt.encode({"sub": "u1", "jti": "j1", "scope": "user", "groups": []}, + pem_priv, algorithm="EdDSA") + + with pytest.raises(HandshakeError) as excinfo: + authorize_token(token, pem_pub, group_id="g" * 32) + assert excinfo.value.code == "not_a_member" diff --git a/packages/meshbay-hub/src/meshbay_hub/static/app.js b/packages/meshbay-hub/src/meshbay_hub/static/app.js index 1ef878a..6fefe0f 100644 --- a/packages/meshbay-hub/src/meshbay_hub/static/app.js +++ b/packages/meshbay-hub/src/meshbay_hub/static/app.js @@ -765,7 +765,7 @@ async function pipelinedDownload(transport, gekKey, fileId, totalChunks, onChunk return results; } -function GroupPage({ groupId, group, token, username, userId }) { +function GroupPage({ groupId, group, token, username, userId, onRefreshAuth }) { const [status, setStatus] = useState('idle'); const [entries, setEntries] = useState([]); const [cached, setCached] = useState(false); @@ -786,6 +786,9 @@ function GroupPage({ groupId, group, token, username, userId }) { const [retryKey, setRetryKey] = useState(0); const transportRef = useRef(null); const gekRef = useRef(null); + // One refresh per mount: if a fresh token still says we are not a member, we + // really are not, and retrying forever would hide that. + const refreshedRef = useRef(false); const submitJoinCode = useCallback((e) => { e.preventDefault(); @@ -902,14 +905,24 @@ function GroupPage({ groupId, group, token, username, userId }) { cacheGroupIndex(groupId, group ? group.name : groupId, freshEntries); } catch (err) { - if (!cancelled) { - // The node has never seen this browser for this account: it needs a - // one-time code from the operator before it will hand over the group - // key. Not an error to shout about — a step in joining. - if (err.reason === 'code_required') setNeedsCode(true); - setError(err.message); - setStatus('error'); + if (cancelled) return; + + // Our token predates being added to this group. Refresh once and retry + // rather than telling someone who was just invited that they are not a + // member — which is what the node honestly sees, and is useless to them. + if (err.reason === 'not_a_member' && !refreshedRef.current && onRefreshAuth) { + refreshedRef.current = true; + try { + if (await onRefreshAuth()) return; // new token → effect re-runs + } catch { /* fall through to the message below */ } } + + // The node has never seen this browser for this account: it needs a + // one-time code from the operator before it will hand over the group + // key. Not an error to shout about — a step in joining. + if (err.reason === 'code_required') setNeedsCode(true); + setError(err.message); + setStatus('error'); } }; @@ -2653,6 +2666,20 @@ function App() { }, }; + // Group membership is baked into the access token at login and the hub does not + // push updates, so someone invited after they signed in carries a token that + // says they are in nothing. Refreshing re-reads membership from the database. + const refreshAuth = useCallback(async () => { + if (!user || !user.refreshToken) return null; + const data = await hubFetch('/v1/users/token/refresh', { + method: 'POST', body: { refresh_token: user.refreshToken }, + }); + const u = { ...user, token: data.access_token }; + setUser(u); + saveAuth(u); + return data.access_token; + }, [user]); + let page; if (route === '/login' || route === '/register') { page = route === '/register' @@ -2677,7 +2704,8 @@ function App() { const group = groups.find(g => g.id === groupId); page = html`<${GroupPage} groupId=${groupId} group=${group} token=${user.token} - username=${user.username} userId=${user.userId} />`; + username=${user.username} userId=${user.userId} + onRefreshAuth=${refreshAuth} />`; } else if (route === '/admin') { page = (user.role === 'moderator' || user.role === 'admin') ? html`<${AdminPage} token=${user.token} />` diff --git a/packages/meshbay-hub/src/meshbay_hub/static/transport.js b/packages/meshbay-hub/src/meshbay_hub/static/transport.js index 271d11f..c200674 100644 --- a/packages/meshbay-hub/src/meshbay_hub/static/transport.js +++ b/packages/meshbay-hub/src/meshbay_hub/static/transport.js @@ -314,8 +314,13 @@ class MeshBayTransport { // A node that answers a handshake with anything other than a challenge is not // running the mutual protocol. Accepting a bare handshake_ack here would let a // peer skip proving GEK possession entirely (C3/C6). - throw new Error( + const rejected = new Error( 'MNP handshake rejected: ' + (reply.detail || `unexpected ${reply.type}`)); + // `not_a_member` usually means our token predates being added to the group; + // the caller refreshes it and tries again rather than showing that to someone + // who was invited thirty seconds ago. + rejected.reason = reply.code || ''; + throw rejected; } /** diff --git a/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py b/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py index 416e84c..46dda64 100644 --- a/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py +++ b/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py @@ -356,7 +356,8 @@ class WebRTCPeerSession: except HandshakeError as refusal: # HandshakeError messages are authored to be peer-safe, unlike arbitrary # exception text (L3) — the client needs to know *why* it was refused. - self._send({"type": "error", "detail": str(refusal)}) + self._send({"type": "error", "detail": str(refusal), + "code": getattr(refusal, "code", "")}) self._audit_auth_failed(group_id, str(refusal)) return |