Joseph Doherty
0329fa4d4b
Stage 2a. Clients present the static username "apikey" with an
otua_<keyId>_<secret> credential as the password; the key resolves to a
principal. LDAP registrations are deliberately RETAINED for AdminUI login —
only IOpcUaUserAuthenticator moves, which is what D2 asked for.
The load-bearing decision here is what roles a key gets. The two live gates
(WriteOperate on Value writes, AlarmAck on Part 9 methods) check a SERVER-WIDE
role set, so the cutover has to keep producing one or it would lock every client
out of writes long before per-node evaluation lands in stage 5.
ApiKeyInterimRoleMapper therefore maps ACL grants to roles, but ONLY
cluster-scoped ones. The obvious version — union the permission flags across all
of a principal's grants — would let a grant authored narrowly ("WriteOperate on
Equipment X") confer server-wide write authority, because nothing in the pipeline
can enforce scope yet. That fails in the dangerous direction: the operator's
narrow intent silently becomes broad. Restricting to cluster scope under-grants
instead, which is no worse than today (where every ACL row does nothing) and can
never exceed what was authored. Falsified: deleting the scope check reds exactly
A_narrower_scoped_write_grant_confers_nothing_yet and nothing else.
Verification is one indexed lookup plus one HMAC, with no network I/O at all.
That matters because the SDK raises ImpersonateUser synchronously while holding a
SessionManager-wide event lock, so this path does not stall one request — it
serializes every session activation server-wide. It is the main practical gain
over the LDAP bind it replaces.
Every rejection returns one opaque message so the server cannot be used as an
oracle for whether a key id exists or which half of a credential was wrong; a
test asserts the failure modes really are indistinguishable AND that a valid key
still succeeds, so it cannot pass by denying everything.
Caught while wiring: OtOpcUaServerHostedService takes IOpcUaUserAuthenticator as
a REQUIRED ctor parameter, so leaving a driver-only node unregistered is not a
quiet fallback to deny-all — it fails DI and the node does not boot.
NullOpcUaUserAuthenticator is now registered explicitly there. A driver-only node
has no ConfigDb since Phase 4 and so has no key source until the artifact-backed
store lands in stage 4; it denies UserName tokens until then, which is the safe
direction, and anonymous sessions are unaffected.
LdapOpcUaUserAuthenticator is now registered nowhere and is dead code. Deleting
it plus LdapOpcUaUserAuthenticatorTests / LdapAuthResilienceTests /
LdapGlauthOutageLiveTests is stage 2b, kept separate because those cover a
live-gated resilience feature (hard wall-clock bound, bounded concurrency,
directory-outage circuit) that exists precisely BECAUSE the LDAP bind ran inline
on session activation — a constraint the key path does not have. That deserves
its own commit, not a footnote in this one.
Anonymous-as-a-grantable-principal (D3) is also stage 2b.
Host 37, Security 89, OpcUaServer 364 green.
Claude-Session: https://claude.ai/code/session_015p7wGqy3YpZNCpDzTpGMKo
OtOpcUa
OPC UA server (.NET 10 AnyCPU) that exposes a fleet of industrial drivers as a single OPC UA address space. Drivers ship in-process for AVEVA System Platform Galaxy (via the sibling mxaccessgw repo), Modbus TCP, Siemens S7, Allen-Bradley CIP (ControlLogix / CompactLogix), Allen-Bradley Legacy (SLC 500 / MicroLogix), Beckhoff TwinCAT (ADS), FANUC FOCAS, OPC UA Client (gateway), and MQTT (broker subscribe; Sparkplug B in progress).
A cross-platform client stack (.NET 10) — shared library, CLI, and Avalonia desktop app — connects to any OPC UA server.
Architecture
OPC UA Clients (CLI, Desktop UI, 3rd-party)
|
v
+-------------------------------------+
| OtOpcUa.Server (.NET 10 AnyCPU) |
| address space + capability fan-out|
+-------------------------------------+
| | | | | | | |
Galaxy Modbus S7 AbCip AbLeg TwinCAT FOCAS OpcUaClient MQTT
|
v
mxaccessgw (sibling repo, gRPC)
|
v
MXAccess COM (x86 worker, on AVEVA box)
Galaxy is the only driver with an external runtime: it speaks gRPC to a separately installed mxaccessgw server (sibling repo at c:\Users\dohertj2\Desktop\mxaccessgw\) which owns the MXAccess COM apartment and the x86/STA bitness constraint server-side. Everything in this repo is platform-agnostic .NET 10.
Prerequisites
- .NET 10 SDK (server, drivers, clients all target .NET 10)
- SQL Server reachable for the central config DB
- For Galaxy specifically: a running
mxaccessgwdeployment — see docs/v2/Galaxy.ParityRig.md - For historian read-back / alarm history / continuous historization: a running
ZB.MOM.WW.HistorianGatewaydeployment (the sole historian backend; consumed as theZB.MOM.WW.HistorianGateway.ClientgRPC package). It must runRuntimeDb:Enabled=true+RuntimeDb:EventReadsEnabled=true, and the API key must carryhistorian:read+historian:write+historian:tags:writescopes.
Quick Start
dotnet restore ZB.MOM.WW.OtOpcUa.slnx
dotnet build ZB.MOM.WW.OtOpcUa.slnx
dotnet test ZB.MOM.WW.OtOpcUa.slnx
# Run the server in dev (foreground)
dotnet run --project src/Server/ZB.MOM.WW.OtOpcUa.Host
The server starts on opc.tcp://localhost:4840 with the None security profile. Configure Security.Profiles in src/Server/ZB.MOM.WW.OtOpcUa.Host/appsettings.json to enable Basic256Sha256-Sign or Basic256Sha256-SignAndEncrypt. See docs/security.md.
Install as Windows Services
Production deployment is driven by scripts/install/Install-Services.ps1, which registers the OtOpcUa server service under a chosen service account. Historian support requires a separately deployed ZB.MOM.WW.HistorianGateway and Galaxy support a separately installed mxaccessgw — neither this repo nor the install script provisions them.
.\scripts\install\Install-Services.ps1 `
-InstallRoot 'C:\Program Files\OtOpcUa' `
-ServiceAccount 'DOMAIN\svc-otopcua'
The historian backend is the external ZB.MOM.WW.HistorianGateway (not installed by this script). See the script header and docs/ServiceHosting.md for full options.
Client CLI
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- connect -u opc.tcp://localhost:4840
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- browse -u opc.tcp://localhost:4840 -r -d 3
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- read -u opc.tcp://localhost:4840 -n "ns=2;s=SomeNode"
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- write -u opc.tcp://localhost:4840 -n "ns=2;s=SomeNode" -v 42
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- subscribe -u opc.tcp://localhost:4840 -n "ns=2;s=SomeNode" -i 500
See docs/Client.CLI.md and docs/Client.UI.md.
Documentation
Architecture deep-dives
| Topic | Doc |
|---|---|
| OPC UA server composition, namespace fan-out, Polly invoker | docs/OpcUaServer.md |
| Address space layout | docs/AddressSpace.md |
| Read / Write dispatch (driver vs virtual vs scripted-alarm) | docs/ReadWriteOperations.md |
| Incremental sync (driver-backend rediscovery + config publishes) | docs/IncrementalSync.md |
| Service hosting (Server + Admin; external HistorianGateway backend) | docs/ServiceHosting.md |
| Security (transport, LDAP, certificates) | docs/security.md |
| Redundancy | docs/Redundancy.md |
| Status dashboard | docs/StatusDashboard.md |
Drivers
| Topic | Doc |
|---|---|
| Driver specs (per-driver capability surface, config, addressing) | docs/v2/driver-specs.md |
| Galaxy driver | docs/drivers/Galaxy.md |
| Modbus / S7 / AbCip / AbLegacy / TwinCAT / FOCAS / OpcUaClient / MQTT | docs/drivers/ |
| Galaxy parity rig (mxaccessgw setup) | docs/v2/Galaxy.ParityRig.md |
| Galaxy performance + tracing | docs/v2/Galaxy.Performance.md |
Clients
| Topic | Doc |
|---|---|
| Client CLI | docs/Client.CLI.md |
| Client UI (Avalonia desktop) | docs/Client.UI.md |
v1 archive
The original v1 in-process MXAccess docs (Galaxy.Host topology, Configuration env vars, AlarmTracking, DataTypeMapping, HistoricalDataAccess, Subscriptions, etc.) are preserved under docs/v1/ — historical reference only. PR 7.2 retired the v1 architecture on 2026-04-30; current state is documented in the sections above.
License
Internal use only.