docs(ledger): CF-005 — connect-side serving path has no caller-identity capture (alktunnels reverse-flow POC W1)

docs/reviews/consumer-findings-ledger.md

@@ -11,7 +11,43 @@ Format: date | found-in (alkhttp context) | severity | status.
 
 ## Open
 
-(none)
+### CF-005 — connect-side serving path (`from_connection_with_serving`) has no caller-identity capture; scope-gated ops are satisfiable only via payload `auth_token` (2026-09-07)
+
+- **Found in:** alktunnels reverse-flow POC
+  (`alktunnels-reverse-poc`, summary at
+  `/workspace/@alkdev/alktunnels/docs/research/reverse-poc-summary.md`
+  §W1; verified against alkcall 0.6.0). The worker is the connect side
+  AND the serving side (ADR-022 §2 both-sides): it serves its tunnel
+  open op to the hub over the connection it dialed. The open op is
+  scope-gated (`AccessControl.required_scopes`), but the identity the
+  ACL sees comes from `Dispatcher::dispatch_start` →
+  `resolve_identity(connection_identity, payload)`, and:
+  - `connection.identity()` is `None` — `from_connection_with_serving`
+    builds channel 0 internally via `Connection::from_source`
+    (`client.rs` channel-0 block) and never sets an identity; there is
+    no capture point for the transport-authenticated peer
+    (mTLS/QUIC identity) on this path.
+  - The only caller-identity path is the payload `auth_token` →
+    `ServingConfig.identity_provider` (`resolve_from_token`).
+  - Corollary: the `AuthContext` closed over by
+    `register_openable*`'s wrapper (what the establisher and pump
+    handler receive) is the connection-establishment-time context, not
+    the per-call opener's identity — on the accept side the install
+    hook receives the transport `AuthContext` and can
+    `channel0_conn.set_identity`, but `from_connection_with_serving`
+    has no equivalent seam.
+- **Impact:** a connect-side serving op with a scope gate cannot
+  authenticate the legitimate peer by transport identity — the POC
+  had to attach `auth_token` payloads from the hub side
+  (`CallConnection::call_with_payload`). Acceptable for hub-forwarding
+  topologies (from_call's ADR-017 §7 token path), but a gap for
+  direct connect-side serving where the transport already
+  authenticated the peer.
+- **Candidate remediations (upstream's call):** (a) `ServingConfig`
+  gains an optional identity (or the channel-0 connection is exposed
+  for `set_identity` before the serving loop starts); (b) documented
+  token-only posture for connect-side serving. Either is additive.
+- **Status:** open — filed 2026-09-07 (alktunnels reverse-flow POC W1).
 
 ---