Merge fix/issues-543-544-545: whitespace-key fail-closed backport (#543), de-flaked deadline test (#544), h2c accepted-posture record (#545)

Claude-Session: https://claude.ai/code/session_014WNM4vjoVksyyBraTXSZE1

docs/Configuration.md

@@ -184,6 +184,8 @@ The checked-in `appsettings*.json` files are deliberately thin: they carry only
 
 **Both command-plane gRPC services ride an existing listener — neither claims a port of its own.** `NodeCommandService` is mapped alongside `TelemetryStreamGrpcService` on the driver-role node's `Telemetry:GrpcListenPort` listener (the docker-dev rig's `:4056`) whenever that port is bound, deliberately NOT gated on `MeshTransport:Mode` — mapping it under `Dps` costs nothing (nothing dials it), whereas gating it would mean a running fleet needs a central restart before any node could ack after flipping the mode. `CentralCommandService` (the node→central ack ingress) is mapped alongside `DeploymentArtifactService` on the admin-role node's `ConfigServe:GrpcListenPort` listener (the rig's `:4055`), for the same reason — see [`docs/Telemetry.md`](Telemetry.md) for the shared driver-role listener and [§ `ConfigSource`/`ConfigServe`](#configsource--configserve-config-fetch-and-cache) for the shared admin-role one.
 
+**The transport underneath is cleartext h2c, deliberately.** Both command-plane listeners are HTTP/2-only on a plaintext port and every dial is a prior-knowledge `http://host:port` address, so the PSK bearer crosses the wire in the clear on a link assumed private. That posture is **recorded and accepted** for these two planes and the three others that share their shape — see [`security.md` § Internal gRPC planes (h2c)](security.md#internal-grpc-planes-h2c--accepted-cleartext-posture) for the full five-plane table, what each one exposes, and why a TLS option would have to cover all five at once.
+
 On the docker-dev rig every node carries these keys already; the rig's compose default is `Grpc` (`OTOPCUA_MESH_MODE:-Grpc`, cutover commit `caf2eec6`) — the compiled class default in `MeshTransportOptions` stays `Dps`, so an unconfigured deployment outside the rig still needs `Mode=Grpc` set explicitly. Every rig node carries a `cluster-{ClusterId}` role (Phase 6), so `OTOPCUA_MESH_MODE=Dps` is not a usable override on this rig as shipped — `SplitTopologyTransportValidator` refuses to boot any of them on `Dps`.
 
 See the [ClusterClient→gRPC migration design](plans/2026-08-06-clusterclient-to-grpc-design.md), [implementation plan](plans/2026-08-06-clusterclient-to-grpc.md), [tracking doc](plans/2026-08-06-clusterclient-to-grpc-tracking.md) and [live gate](plans/2026-08-06-clusterclient-to-grpc-live-gate.md) for the migration's phase-by-phase history — those are historical records of the cutover and are not updated further by this sweep.

docs/security.md

@@ -104,6 +104,63 @@ The Admin UI `Certificates.razor` page (`src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Co
 - Promote trusted client certs with the Admin UI Certificates page's **Trust** action (FleetAdmin) — or by moving the `.der` from `rejected/` to `trusted/certs/` — rather than relying on the auto-accept fallback.
 - Periodically audit the `rejected/` directory; an unexpected entry is often a misconfigured client or a probe attempt.
 
+### Internal gRPC planes (h2c) — accepted cleartext posture
+
+Everything above concerns the **OPC UA** endpoint — the surface external clients bind to. OtOpcUa
+also runs **five internal gRPC planes** between its own processes (central ↔ driver node, and node ↔
+pair partner). Those are a separate transport story, recorded here so it is written down once rather
+than rediscovered per plane.
+
+| # | Plane | gRPC service | Listener (config key) | Credential (config key) | Interceptor |
+|---|---|---|---|---|---|
+| 1 | Live telemetry stream (central dials the node) | `telemetry.v1.TelemetryStreamService/Subscribe` | driver node, `Telemetry:GrpcListenPort` | `Telemetry:ApiKey` (dialer presents `TelemetryDial:ApiKey`) | `TelemetryStreamAuthInterceptor` |
+| 2 | Config-serve / artifact fetch (node fetches from central) | `deployment_artifact.v1.DeploymentArtifactService/Fetch` | central (admin role), `ConfigServe:GrpcListenPort` | `ConfigServe:ApiKey` (fetcher presents `ConfigSource:ApiKey`) | `ConfigServeAuthInterceptor` |
+| 3 | LocalDb pair sync (one node dials its partner) | `localdb_sync.v1.LocalDbSync/Sync` | driver node, `LocalDb:SyncListenPort` | `LocalDb:Replication:ApiKey` (byte-identical on both nodes of the pair) | `LocalDbSyncAuthInterceptor` |
+| 4 | Mesh commands (central drives the node) | `mesh_transport.v1.NodeCommandService/Execute` | **shares** the node's `Telemetry:GrpcListenPort` listener | `MeshTransport:GrpcPsk` — **per application `Cluster`**, not fleet-wide | `MeshCommandAuthInterceptor` |
+| 5 | Mesh deploy acks (node reports to central) | `mesh_transport.v1.CentralCommandService/ReportApply` | **shares** central's `ConfigServe:GrpcListenPort` listener | per-cluster key resolved by `IMeshPskProvider` — `MeshTransport:ClusterPsks:<clusterId>` override, else the `OT-MESH-PSK-<clusterId>` secret | `CentralCommandAuthInterceptor` |
+
+Planes 4 and 5 claim no port of their own; they ride the listener their sibling already binds. On the
+docker-dev rig those two config keys resolve to `:4056` (driver nodes) and `:4055` (central) — rig
+values of the keys above, **not** hardcoded ports.
+
+**The posture.** All five listeners are bound `HttpProtocols.Http2` on a **cleartext** port, and every
+client dials a prior-knowledge `http://host:port` address — h2c, no TLS, no ALPN. (Cleartext is
+structural, not incidental: a cleartext `Http1AndHttp2` endpoint cannot negotiate HTTP/2 without ALPN,
+which is why these are dedicated HTTP/2-only ports rather than a multiplex onto the main one.)
+Authentication on all five is a **shared bearer token in an `Authorization` header**, compared in
+constant time and fail-closed when unconfigured. Because the transport is cleartext, **the bearer
+itself crosses the wire in the clear** — anyone who can observe or interpose on the link can read a
+key and then replay it.
+
+What that buys an attacker is not uniform:
+
+- Planes 1–2 are **read** surfaces: the live telemetry feed, and the full deployed configuration.
+- Plane 3 **writes** rows into a node's deployment-artifact cache — which is what that node boots
+  from when central SQL is unreachable.
+- Planes 4–5 are the **command** surfaces, and are the sharpest: plane 4 carries `RestartDriver`,
+  `AlarmCommand` and deployment dispatch; plane 5 carries the apply acks the deploy coordinator
+  counts, so forged acks can seal a deployment nodes never applied.
+
+**Decision: risk accepted, 2026-08-06** (Gitea [`lmxopcua#545`](https://gitea.dohertylan.com/dohertj2/lmxopcua/issues/545),
+option 1). Accepted once, for all five planes together, on the **trusted-link assumption every one of
+them already makes**: the central↔site and pair-local links are private (VPN or dedicated WAN), not
+routed over anything an untrusted party can observe. Two things bound the consequences if that
+assumption is wrong:
+
+- **Per-cluster PSKs bound blast radius on the two command planes.** A captured `SITE-A` key drives
+  `SITE-A` only; it is refused by `SITE-B`'s node and by central when it claims to be `SITE-B`.
+  A single fleet-wide key would have made one observed link equal to fleet-wide command authority.
+- **Production keys are delivered as `${secret:...}` references**, never committed literals, and
+  **MUST NOT be reused across clusters** — reusing one key collapses the isolation above back into a
+  fleet-wide key with extra steps. The three literal `dev-mesh-psk-*` keys exist only on the
+  docker-dev rig.
+
+**Future work.** The recorded alternative is a `UseTls`/scheme option on these planes (dial `https://`,
+bind the listener with a certificate). If it is ever built it **must cover all five planes together**
+— a mixed posture, where some internal links are encrypted and others are not, is harder to reason
+about than either uniform answer, and invites exactly the "which one was it again?" mistake this note
+exists to prevent. See issue #545.
+
 ---
 
 ## OPC UA Authentication

src/Server/ZB.MOM.WW.OtOpcUa.Host/Configuration/ConfigServeAuthInterceptor.cs

@@ -33,6 +33,11 @@ namespace ZB.MOM.WW.OtOpcUa.Host.Configuration;
 ///         wrong key cannot be recovered byte-by-byte from response timing. Length differences are
 ///         unavoidably observable and are not sensitive.
 ///     </para>
+///     <para>
+///         <b>Exactly one public constructor.</b> <c>Grpc.AspNetCore</c> silently stops invoking an
+///         interceptor that has more than one public ctor — see
+///         <c>ConfigServeAuthInterceptorTests.HasExactlyOnePublicConstructor</c>.
+///     </para>
 /// </remarks>
 public sealed class ConfigServeAuthInterceptor : Interceptor
 {
@@ -110,7 +115,9 @@ public sealed class ConfigServeAuthInterceptor : Interceptor
             return;
 
         var expected = _options.Value.ApiKey;
-        if (string.IsNullOrEmpty(expected))
+        // Whitespace-only counts as unconfigured: an all-blank expected key would otherwise be
+        // satisfied by an all-blank bearer token, which is no gate at all.
+        if (string.IsNullOrWhiteSpace(expected))
         {
             _logger.LogWarning(
                 "Rejected a config-serve call to {Method}: no ConfigServe:ApiKey is configured, so the " +

src/Server/ZB.MOM.WW.OtOpcUa.Host/Configuration/LocalDbSyncAuthInterceptor.cs

@@ -38,6 +38,11 @@ namespace ZB.MOM.WW.OtOpcUa.Host.Configuration;
 ///         a wrong key cannot be recovered byte-by-byte from response timing. Length differences are
 ///         unavoidably observable and are not sensitive.
 ///     </para>
+///     <para>
+///         <b>Exactly one public constructor.</b> <c>Grpc.AspNetCore</c> silently stops invoking an
+///         interceptor that has more than one public ctor — see
+///         <c>LocalDbSyncAuthInterceptorTests.HasExactlyOnePublicConstructor</c>.
+///     </para>
 /// </remarks>
 public sealed class LocalDbSyncAuthInterceptor : Interceptor
 {
@@ -115,7 +120,9 @@ public sealed class LocalDbSyncAuthInterceptor : Interceptor
             return;
 
         var expected = _options.Value.ApiKey;
-        if (string.IsNullOrEmpty(expected))
+        // Whitespace-only counts as unconfigured: an all-blank expected key would otherwise be
+        // satisfied by an all-blank bearer token, which is no gate at all.
+        if (string.IsNullOrWhiteSpace(expected))
         {
             _logger.LogWarning(
                 "Rejected a LocalDb sync call to {Method}: no LocalDb:Replication:ApiKey is configured, " +

src/Server/ZB.MOM.WW.OtOpcUa.Host/Configuration/TelemetryStreamAuthInterceptor.cs

@@ -117,7 +117,9 @@ public sealed class TelemetryStreamAuthInterceptor : Interceptor
             return;
 
         var expected = _options.Value.ApiKey;
-        if (string.IsNullOrEmpty(expected))
+        // Whitespace-only counts as unconfigured: an all-blank expected key would otherwise be
+        // satisfied by an all-blank bearer token, which is no gate at all.
+        if (string.IsNullOrWhiteSpace(expected))
         {
             _logger.LogWarning(
                 "Rejected a telemetry stream call to {Method}: no Telemetry:ApiKey is configured, so " +

tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/ConfigPublishCoordinatorTimeoutTests.cs

@@ -22,11 +22,11 @@ public sealed class ConfigPublishCoordinatorTimeoutTests : ControlPlaneActorTest
         var dbFactory = NewInMemoryDbFactory();
         var deploymentId = SeedDispatchingDeployment(dbFactory);
 
-        // Short deadline so we can drive it deterministically in the test.
+        // Seed the NodeDeploymentState row BEFORE the actor is spawned. PreStart reads
-        var actor = Sys.ActorOf(ConfigPublishCoordinator.Props(dbFactory, TimeSpan.FromMilliseconds(150)));
+        // NodeDeploymentStates to recover the expected-ack set, and it runs as soon as Sys.ActorOf
-
+        // schedules the actor — so seeding afterwards is a race: if PreStart wins, the coordinator
-        // Seed a NodeDeploymentState row so the coordinator doesn't see "zero expected acks"
+        // sees zero expected acks and can short-circuit straight to Sealed, and the assertion below
-        // and short-circuit to Sealed. We pretend a driver node exists in the cluster.
+        // never sees TimedOut. We pretend a driver node exists in the cluster.
         using (var db = dbFactory.CreateDbContext())
         {
             db.NodeDeploymentStates.Add(new Configuration.Entities.NodeDeploymentState
@@ -38,6 +38,13 @@ public sealed class ConfigPublishCoordinatorTimeoutTests : ControlPlaneActorTest
             db.SaveChanges();
         }
 
+        // Deliberately un-hittable wall-clock deadline (matching the other tests in this class).
+        // The apply deadline is a real Akka timer: a short one can self-fire under load and race
+        // the explicit DeadlineElapsed below, so the test would sometimes be measuring the timer
+        // rather than the message handler. Five minutes guarantees the ONLY deadline signal the
+        // coordinator ever receives is the one this test sends.
+        var actor = Sys.ActorOf(ConfigPublishCoordinator.Props(dbFactory, TimeSpan.FromMinutes(5)));
+
         // Drive the deadline ourselves rather than waiting for the cluster's empty driver-set
         // bypass. Tell the actor the deadline elapsed for this id.
         actor.Tell(new ConfigPublishCoordinator.DeadlineElapsed(deploymentId));

tests/Server/ZB.MOM.WW.OtOpcUa.Host.IntegrationTests/ConfigServeAuthInterceptorTests.cs

@@ -65,6 +65,19 @@ public sealed class ConfigServeAuthInterceptorTests
         ex.StatusCode.ShouldBe(StatusCode.Unauthenticated);
     }
 
+    [Fact]
+    public async Task FetchMethod_WithBlankKeyConfigured_IsDenied()
+    {
+        // Blank is distinct from unset in configuration (a stray-whitespace appsettings value) but
+        // must be treated identically here: an all-blank expected key would be satisfied by an
+        // all-blank bearer. Pinned identically on MeshCommandAuthInterceptor.
+        var interceptor = CreateInterceptor("   ");
+        var context = CreateContext(FetchMethod, "Bearer    ");
+
+        var ex = await Should.ThrowAsync<RpcException>(() => Invoke(interceptor, context));
+        ex.StatusCode.ShouldBe(StatusCode.Unauthenticated);
+    }
+
     [Fact]
     public async Task FetchMethod_WithNoBearerToken_IsDenied()
     {
@@ -121,6 +134,16 @@ public sealed class ConfigServeAuthInterceptorTests
         ex.StatusCode.ShouldBe(StatusCode.Unauthenticated);
     }
 
+    [Fact]
+    public void HasExactlyOnePublicConstructor()
+    {
+        // Grpc.AspNetCore silently stops invoking an interceptor with more than one public ctor —
+        // this pins the shape so a well-meaning overload doesn't quietly disable auth in production.
+        var publicCtors = typeof(ConfigServeAuthInterceptor).GetConstructors();
+
+        publicCtors.Length.ShouldBe(1);
+    }
+
     /// <summary>
     ///     Minimal <see cref="ServerCallContext"/> carrying just a method name and request headers —
     ///     the only two things the interceptor reads. Hand-rolled because

tests/Server/ZB.MOM.WW.OtOpcUa.Host.IntegrationTests/LocalDbSyncAuthInterceptorTests.cs

@@ -99,6 +99,19 @@ public sealed class LocalDbSyncAuthInterceptorTests
         ex.StatusCode.ShouldBe(StatusCode.PermissionDenied);
     }
 
+    [Fact]
+    public async Task SyncMethod_WithBlankKeyConfigured_IsDenied()
+    {
+        // Blank is distinct from unset in configuration (a stray-whitespace appsettings value) but
+        // must be treated identically here: an all-blank expected key would be satisfied by an
+        // all-blank bearer. Pinned identically on MeshCommandAuthInterceptor.
+        var interceptor = CreateInterceptor("   ");
+        var context = CreateContext(SyncMethod, "Bearer    ");
+
+        var ex = await Should.ThrowAsync<RpcException>(() => Invoke(interceptor, context));
+        ex.StatusCode.ShouldBe(StatusCode.PermissionDenied);
+    }
+
     [Fact]
     public async Task SyncMethod_WithNoBearerToken_IsDenied()
     {
@@ -152,6 +165,16 @@ public sealed class LocalDbSyncAuthInterceptorTests
         ex.StatusCode.ShouldBe(StatusCode.PermissionDenied);
     }
 
+    [Fact]
+    public void HasExactlyOnePublicConstructor()
+    {
+        // Grpc.AspNetCore silently stops invoking an interceptor with more than one public ctor —
+        // this pins the shape so a well-meaning overload doesn't quietly disable auth in production.
+        var publicCtors = typeof(LocalDbSyncAuthInterceptor).GetConstructors();
+
+        publicCtors.Length.ShouldBe(1);
+    }
+
     [Fact]
     public async Task DuplexStreaming_IsGated_BecauseThatIsHowSyncActuallyRuns()
     {

tests/Server/ZB.MOM.WW.OtOpcUa.Host.Tests/Configuration/TelemetryStreamAuthInterceptorTests.cs

@@ -65,6 +65,19 @@ public sealed class TelemetryStreamAuthInterceptorTests
         ex.StatusCode.ShouldBe(StatusCode.PermissionDenied);
     }
 
+    [Fact]
+    public async Task SubscribeMethod_WithBlankKeyConfigured_IsDenied()
+    {
+        // Blank is distinct from unset in configuration (a stray-whitespace appsettings value) but
+        // must be treated identically here: an all-blank expected key would be satisfied by an
+        // all-blank bearer. Pinned identically on MeshCommandAuthInterceptor.
+        var interceptor = CreateInterceptor("   ");
+        var context = CreateContext(SubscribeMethod, "Bearer    ");
+
+        var ex = await Should.ThrowAsync<RpcException>(() => Invoke(interceptor, context));
+        ex.StatusCode.ShouldBe(StatusCode.PermissionDenied);
+    }
+
     [Fact]
     public async Task SubscribeMethod_WithNoBearerToken_IsDenied()
     {