2 files changed, 59 insertions, 8 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/transport/quic_server.py b/packages/meshbay-node/src/meshbay_node/transport/quic_server.py
index ede756e..7bb6ce5 100644
--- a/packages/meshbay-node/src/meshbay_node/transport/quic_server.py
+++ b/packages/meshbay-node/src/meshbay_node/transport/quic_server.py
@@ -50,22 +50,69 @@ ALPN       = ["meshbay-mnp"]
 
 
 class Denylist:
-    """Shared denylist for revoked users and invalidated JWTs."""
+    """
+    Denylist for revoked users, groups and invalidated JWTs.
 
-    def __init__(self):
+    Finding H4: revocations used to live only in memory, so a node restart silently
+    un-revoked everyone, and group revocations were dropped entirely — the hub
+    signed and broadcast them but the node's handler only understood "user" and
+    "jti". Now persisted to disk and group targets are honoured.
+    """
+
+    def __init__(self, path: Path | None = None):
         self.user_ids: set[str] = set()
+        self.group_ids: set[str] = set()
         self.jtis: set[str] = set()
+        self._path = path
+        self._load()
 
-    def is_denied(self, user_id: str, jti: str) -> bool:
-        return user_id in self.user_ids or jti in self.jtis
+    def is_denied(self, user_id: str, jti: str, group_id: str = "") -> bool:
+        return (user_id in self.user_ids
+                or jti in self.jtis
+                or (bool(group_id) and group_id in self.group_ids))
 
     def deny_user(self, user_id: str) -> None:
         self.user_ids.add(user_id)
         log.info("Denied user: %s", user_id[:8])
+        self._save()
+
+    def deny_group(self, group_id: str) -> None:
+        self.group_ids.add(group_id)
+        log.info("Denied group: %s", group_id[:8])
+        self._save()
 
     def deny_jti(self, jti: str) -> None:
         self.jtis.add(jti)
         log.info("Denied jti: %s", jti[:8])
+        self._save()
+
+    def _load(self) -> None:
+        if not self._path or not self._path.exists():
+            return
+        try:
+            import json
+            data = json.loads(self._path.read_text())
+            self.user_ids = set(data.get("users", []))
+            self.group_ids = set(data.get("groups", []))
+            self.jtis = set(data.get("jtis", []))
+            log.info("Denylist loaded: %d users, %d groups, %d jtis",
+                     len(self.user_ids), len(self.group_ids), len(self.jtis))
+        except Exception as e:
+            log.warning("Could not load denylist from %s: %s", self._path, e)
+
+    def _save(self) -> None:
+        if not self._path:
+            return
+        try:
+            import json
+            self._path.parent.mkdir(parents=True, exist_ok=True)
+            self._path.write_text(json.dumps({
+                "users": sorted(self.user_ids),
+                "groups": sorted(self.group_ids),
+                "jtis": sorted(self.jtis),
+            }))
+        except Exception as e:
+            log.warning("Could not persist denylist to %s: %s", self._path, e)
 
 
 # ── Wire helpers ──────────────────────────────────────────────────────────────
@@ -156,7 +203,8 @@ class _MNPServerProtocol(QuicConnectionProtocol):
             return
 
         denylist = self._ctx.get("denylist")
-        if denylist and denylist.is_denied(decoded.get("sub", ""), decoded.get("jti", "")):
+        if denylist and denylist.is_denied(
+                decoded.get("sub", ""), decoded.get("jti", ""), group_id):
             self._send(stream_id, {"type": "error", "detail": "Token revoked"})
             self._quic.close()
             return
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 9fb9ef2..43e6fdc 100644
--- a/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py
+++ b/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py
@@ -241,8 +241,10 @@ class WebRTCPeerSession:
             else:
                 log.warning("Unknown MNP message type on DataChannel: %s", mtype)
         except Exception as e:
-            log.error("Error handling %s on DataChannel: %s", mtype, e)
-            self._send({"type": "error", "detail": str(e)})
+            # Log the detail locally; send the peer a generic message. Exception
+            # text here carries filesystem paths and internal state (finding L3).
+            log.error("Error handling %s on DataChannel: %s", mtype, e, exc_info=True)
+            self._send({"type": "error", "detail": "Request failed"})
 
     def _audit(self, event: str, detail: str = "") -> None:
         audit = self._ctx.get("audit_store")
@@ -269,7 +271,8 @@ class WebRTCPeerSession:
             return
 
         denylist = self._ctx.get("denylist")
-        if denylist and denylist.is_denied(decoded.get("sub", ""), decoded.get("jti", "")):
+        if denylist and denylist.is_denied(
+                decoded.get("sub", ""), decoded.get("jti", ""), group_id):
             self._send({"type": "error", "detail": "Token revoked"})
             return