romanett
2871355d18
## Summary Implements the **GDS AliasName Server facet** (OPC 10000-17 Annex C) in `Opc.Ua.Gds.Server`, so that the CTT conformance unit *GDS AliasName Discovery* passes apart from two CTT script defects (documented, Mantis drafts in `plans/ctt-issues.md`). Spec requirements: - **C.1:** aggregate the AliasNames of registered Servers that expose the `ALIAS` capability (OPC 10000-12 Annex D). Pull all AliasNameCategory instances and merge those whose BrowseNames have the same Name. Provide the ExpandedNodeId of every referenced node and the ServerUri of the Server that contains it. - **C.2:** on registration, merge the Server's AliasNames into a single tree for TagVariables/Topics, combine aliases that share a name, and add the ServerUri to `ServerArray`. - **C.3:** on unregistration, remove that Server's aliases and categories (but keep those other Servers still provide), remove its AliasFor references, and remove its ServerUri from `ServerArray`. ### Design - **`AliasNameAggregator`** (`Opc.Ua.Gds.Server.AliasNames`) holds one snapshot per registered application and builds the merged view: - Categories are keyed by their BrowseName path below `Aliases`. Aliases are merged by name within a category; their targets are the union over all sources. - Targets are stored as namespace-URI ExpandedNodeIds. The ServerIndex is resolved against the server's `ServerArray` each time the view is built, because removing a ServerUri renumbers the entries after it. - Only ServerUris the aggregator added itself are removed again. - Also implements `FindAlias`/`FindAliasVerbose`, recursive over sub-categories. - **`SessionAliasNameSourceReader`** reads a source over a client Session by browsing the `Aliases` (i=23470) hierarchy and the AliasFor references. - It browses instead of calling `FindAlias` because the category structure has to be aggregated too, and a source whose aliases come from a NodeSet (like the CTT's embedded server) does not implement `FindAlias`. - It connects anonymously, to the most secure endpoint first, falling back to SecurityMode None. It runs GetEndpoints once per DiscoveryUrl. - **`ApplicationsNodeManager`** (new partial `ApplicationsNodeManager.AliasNames.cs`): - Hooks RegisterApplication (now `OnCallAsync`), UpdateApplication (background re-read) and UnregisterApplication. - Materializes the merged view as `AliasNameType` and `AliasNameCategoryType` nodes in the GDS application-record namespace, organized by the well-known TagVariables/Topics/Aliases objects. Each category gets a `FindAlias` answered from the merged list. - Changes and node updates are serialized, so a read that finishes after a concurrent unregister cannot re-add the source. - RegisterApplication waits at most `AliasNameRegistrationWait` (5 s) for the read; a slower or unreachable source is finished in the background and never blocks clients past their call timeout. - Optional periodic re-read via `AliasNameRefreshInterval`; it also retries sources that could not be read. - **`IAliasNameStoreRegistry.RegisterContributor`/`UnregisterContributor`** (Opc.Ua.Server): a read-only contributor's aliases are added to the `FindAlias`/`FindAliasVerbose` results of the categories it reports, next to the owning store's. This lets the aggregated aliases share the well-known categories with the server's own aliases, which matters for the reference server, an AliasName Server and a GDS at once. Contributors never receive Add/Delete calls. - **Opt-in:** `GlobalDiscoveryServerConfiguration.EnableAliasNameAggregation` is off by default, because the GDS then opens client connections to the DiscoveryUrls of registered applications. `Ctt.ReferenceServer.Config.xml` enables it. - `Opc.Ua.Gds.Server` now references `Opc.Ua.Client`; the `Opc.Ua` meta-package already depends on both. ### CTT (1.05.513 with the patched scripts), p14-gds, reference server `--ctt`, embedded CTT source + 2 extra AliasName sources | GDS AliasName Discovery | before | after | after, with the C54/C55 script fixes | | --- | --- | --- | --- | | initialize | Skipped (no sources) | Pass | Pass | | 001 | Error | Error (C55) | Pass | | 002 | Error | Error (C54) | Warning (RegisterApplication > 100 ms) | | 003 | Pass | Pass | Pass | | 004 | Error | Error (C54) | Pass | | 005 | Skipped | Error (C55) | Pass | | 006, 007, 009, 011, 012, 014, 015 | Skipped | Error (C54) | Pass | | 008 | Skipped | Pass | Pass | | 010, 013 | Skipped | Error (C55) | Pass | - **C54:** the script compares the GDS's AliasFor target (ServerIndex > 0, namespace URI, as Annex C.1 and Part 4 §7.16 require) with the source's local NodeId using `equals()`, which can never match. - **C55:** "no remote aliases" is checked as "no aliases", so it fails on the reference server's own aliases. Both are documented with draft Mantis texts (not filed). The remaining script checks pass in 15/15 test cases. No regressions: - Application Directory and Query Applications are unchanged against the baseline. The only difference is one ActivateSession timing warning in one run. - p09 (AliasName CUs) passes 32/32, identical to the baseline. ## Tests - `AliasNameAggregatorTests` (unit) covers: - merging across Servers; - categories kept while still referenced and removed after the last source; - ServerArray add, remove and renumbering; - pre-existing ServerUris kept; - local targets; - FindAlias/FindAliasVerbose scope, pattern and reference-type filter. - `GdsAliasNameAggregationTests` (end-to-end) registers a second in-process reference server with `ALIAS` and reads it with the real session reader. It checks: - aggregated nodes and remote AliasFor targets; - the ServerArray entry; - FindAlias on TagVariables and on the aggregated category; - that unregistering removes everything; - that an unreachable source still registers; - that a Server without `ALIAS` is ignored. - Registry contributor tests in `AliasNameStoreRegistryTests`. - Opc.Ua.Gds.Tests: 1246 passed, 0 failed, 56 skipped. Opc.Ua.Server.Tests AliasNames: 198/198. InformationModel and Features alias tests pass. net48 compiles. 🤖 Generated with [Claude Code](https://claude.com/claude-code) --------- Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
OPC Foundation UA .NET Standard Reference Server
Additional samples
- OPC 10000-21 onboarding registrar/client — loads the generated Onboarding companion model, binds the standard registrar administration methods to an injected ticket store, and drives a secure register/unregister round trip with a PowerShell script.
Introduction
This document is referring to the CTT version 1.04.9.398.
This OPC Server is designed to be the default OPC UA Server when opening the OPC UA Compliance Test Tool and it uses an address-space that matches the design of the UACTT and the requirements for OPC UA compliance testing.
It uses the OPC Foundation UA .NET Standard Library. Therefore it supports both the opc.tcp and https transports. There is a .NET framework based server with UI and a .NET Core console version of the server which runs on any OS supporting .NET 8.0 and later.
How to build and run the Windows OPC UA Reference Server with UACTT
- Open the solution UA.slnx with Visual Studio 2026.
- Choose the project
Reference Serverin the Solution Explorer and set it with a right click asStartup Project. - Hit
F5to build and execute the sample.
How to build and run the console OPC UA Reference Server on Windows, Linux and iOS
This section describes how to run the ConsoleReferenceServer.
Please follow instructions in this article to setup the dotnet command line environment for your platform.
Start the server
- Open a command prompt.
- Navigate to the folder samples/Reference/ConsoleReferenceServer.
- To run the server sample type
dotnet run --project ConsoleReferenceServer.csproj. The server is now running and waiting for the connection of the UACTT.
UACTT test certificates
The reference server always rejects new client certificates and requires that the UACTT certificates are in appropriate folders.
- The console server certificates are stored in %LocalApplicationData%/OPC Foundation/pki.
- The Windows .NET framework server stores the certificates in %CommonApplicationData%\OPC Foundation\pki.
- %CommonApplicationData% maps to the path set by the environment variable ProgramData on Windows.
- %LocalApplicationData% maps to a hidden location in the user home folder and depends on the target platform. See Certificates for more information.
Certificate stores
Under pki, the following stores contain certificates under certs, CRLs under crl or private keys under private.
- own contains the reference server public certificate and private key.
- rejected contains the rejected client certificates. To trust a client certificate, copy the rejected certificate to the trusted/certs folder.
- trusted contains trusted client and CAs certificates and CRLs.
- issuer contains CAs certificates and CRLs needed for validation.
- trustedUser contains trusted user and user CA certificates and CRLs.
- issuerUser contains user CA certificates and CRLs needed for validation of the certificate chains.
Placing the UACTT certificates
CTT creates a PKI folder in a new project. There is a subfolder copyToServer which contains the application and user identity certificates. Copy the ApplicationInstance_PKI certificates for testing with the UACTT to the following stores:
- trusted/certs: trusted certificates
- trusted/crl: revocation lists of trusted certificates
- issuer/certs: issuer certificates
- issuer/crl: revocation lists of issuer certificates
Copy the X509UserIdentity_PKI certificates for testing with the UACTT to the following stores:
- trustedUser/certs: trusted user certificates
- trustedUser/crl: revocation lists of trusted user certificates
- issuerUser/certs: user issuer certificates
- issuerUser/crl: revocation lists of user issuer certificates
UACTT Testing
Download and install the OPC UA Compliance Test Tool.
Note: Access to the UACTT is granted to OPC Foundation Corporate Members.
UACTT sample configuration
A sample configuration for the UACTT Version 1.04.9.398 can be found in UAReferenceServer.ctt.xml. Originally the reference server was certified only against the Standard UA Server profile, the Method Server Facet and the DataAccess Server Facet, in addition to all security related profiles. During release testing all Conformance Units should be enabled / checked.
Enabling Alarms & Conditions
The address space for Alarms contains a Start method which needs to be called to produce alarms for CTT testing. The method is called from a connected client.
The ConsoleReferenceServer has also a command line option -ctt which starts the Alarms when the server is started. The following Alarm instances are available for monitoring:
AlarmConditionTypeDiscrepancyAlarmTypeLimitAlarmTypeExclusiveLimitAlarmTypeExclusiveDeviationAlarmTypeExclusiveRateOfChangeAlarmTypeNonExclusiveLimitAlarmTypeNonExclusiveDeviationAlarmTypeNonExclusiveRateOfChangeAlarmTypeDiscreteAlarmTypeSystemOffNormalAlarmTypeExclusiveLevelAlarmTypeNonExclusiveLevelAlarmTypeOffNormalAlarmType
Known missing Tests and Issues
Depending on the setup in the provided project configuration, unsupported profiles should be skipped. At the time of writing (1.4.368) the following tests, profiles or facets are not yet covered or not configured due to issues:
- no support for events, historian and only a few basic Alarms & Conditions.
- Decimal type causes crash of CTT (needs investigation)
- no Image / Enumeration scalar test cases
- Arrays may not include Variant (needs investigation)
- no ArrayItemType implemented
- multiple hierarchical references test node missing
- deprecated security profiles support for SHA1/1k RSA keys implemented not according to certification. SHA1/1k keys can only be turned on/off for all profiles, not just for the deprecated profiles.
- Monitored Items with array are failing a few test cases.
It is recommended to run the server as retail build with disabled logging, to avoid side effects due to timing artifacts when log entries are written to a disk drive.
Running the CTT against a Docker container
Please refer to the Docker container of the Reference Server documentation page. Once setup to map the certificate store and the configuration to a local folder, follow the instructions above to copy the certificates to the PKI and get started.
Finding the Address Space Configuration Code
- Project: Reference Server
- File: ReferenceNodeManager.cs
- Method: CreateAddressSpace
Finding the UA Services
- Project: Opc.Ua.Server
- File: StandardServer.cs