Files
romanett 651beaee1e Fully support AliasNames in ConsoleReferenceServer (#4012) (#4321)
# Description

The CTT AliasName conformance units skip or fail against the
ConsoleReferenceServer. `AliasName Base` skips with *"No instance of
AliasNameType has been found in the address space"*; `Category Tags`,
`Category Topics` and `Hierarchy` fail. Part 17 support landed in #3779,
but aliases live only inside the `IAliasNameStore` — nothing is
browsable, no `AliasNameCategoryType` is nested under another, and the
Topics aliases point at the Server object rather than at a
`PublishedDataSetType` instance.

Part 17 §6.2 clients — the CTT among them — discover aliases by
browsing, not only by calling `FindAlias`. This PR materializes the
store contents as real nodes and fills the three gaps.

### SDK — `Opc.Ua.Server`

* **`DiagnosticsNodeManager.MaterializeRegisteredAliasNameNodesAsync`**
(new, opt-in) walks every registered `IAliasNameStore` and creates one
`AliasNameType` instance per alias — BrowseName carrying the alias name,
`AliasFor` references to its targets, and the inverse `HasAlias`
reference on each local target (via `externalReferences`, since targets
usually live in another node manager) — plus an `AliasNameCategoryType`
instance for every store category the standard NodeSet does not already
ship. Categories whose NodeId belongs to another node manager are
skipped, so an `AliasNameNodeManager` that also registers its store with
the server-wide registry does not get its NodeIds claimed twice.

Opt-in: servers that only need the well-known `FindAlias` to answer from
their store pay nothing. The nodes are a snapshot taken at address-space
creation — later mutations change what `FindAlias` returns but do not
add or remove nodes.

* **Optional Part 17 methods on the well-known categories.** The same
pass instantiates whatever a category declares through
`AliasNameCapabilities`: `FindAliasVerbose` (§6.3.3),
`AddAliasesToCategory` (§6.3.4), `DeleteAliasesFromCategory` (§6.3.5)
and `LastChange` (§6.3.1). Mutations require a `SecurityAdmin` caller on
a `SignAndEncrypt` channel; the gate previously private to
`AliasNameNodeManager` moved to `AliasNameMethodDispatcher` so both
paths share one implementation.

* **`LastChange`** is now tracked per category rather than only for the
standard `Aliases` node, and the duplicated seeding logic collapsed into
one helper.

### Reference server

* A nested **`Devices`** category under `TagVariables` holds
`Pump1_Status` and `Heater_Power`. `FindAlias` on `TagVariables` still
returns all six names through subtree recursion, while `FindAlias` on
`Devices` returns exactly two — which is what the Hierarchy unit checks.
* `ReferenceServerConfigurationNodeManager` creates three
**`PublishedDataSet` instances** under `PublishedDataSets` (`i=17371`)
and the Topics aliases now target them, satisfying the *"is a Dataset"*
check. These are address-space instances only — no PubSub runtime is
added, and the CTT only inspects the target's type definition.

## Note for reviewers — the reserved NodeIds

The optional children are created at the NodeIds the OPC Foundation
reserves for them (`Aliases.FindAliasVerbose` = `i=24054`,
`TagVariables.LastChange` = `i=32854`, …). Those identifiers are
allocated in `StandardTypes.csv` but are **not** declared in the
ModelDesign and **not** present in the published NodeSet, because the
standard address space does not instantiate optional children. The
source generator therefore emits no parent-to-instance mapping and no
`MethodIds` constants for them, so
`DiagnosticsNodeManager.ReservedChildIds` supplies the nine method ids
and the two missing `LastChange` ids explicitly, each traceable to its
registry row. The 18 argument-property ids do have generated
`VariableIds` constants and are referenced through those.

I deliberately did **not** "fix" this by declaring the children in
`tools/Opc.Ua.SourceGeneration.Core/Design/StandardTypes.xml`: that file
is a verbatim copy of upstream
`UA-ModelCompiler/Design.v105/StandardTypes.xml` (the only differences
today are upstream being newer), so a local edit is lost on the next
sync and the NodeIds would silently revert to factory-minted ones.
`docs/AliasNames.md` records this.

Worth raising upstream separately: `StandardTypes.csv` allocates
`Aliases_FindAliasVerbose` and siblings while the ModelDesign never
declares those children, so the ModelCompiler cannot emit ids it has
itself reserved. If that is ever reconciled, `ReservedChildIds` becomes
redundant and deletes cleanly.

## Related Issues

- Fixes #4012

## Checklist

- [x] I have signed the
[CLA](https://opcfoundation.org/license/cla/ContributorLicenseAgreementv1.0.pdf)
and read the
[CONTRIBUTING](https://github.com/OPCFoundation/UA-.NETStandard/blob/master/CONTRIBUTING.md)
doc.
- [x] I have added tests that prove my fix is effective or that my
feature works and increased code coverage.
- [x] I have added all necessary documentation.
- [x] I have verified that my changes do not introduce (new) build or
analyzer warnings.
- [ ] I ran **all** tests locally using the **UA.slnx** solution against
at least .net **framework** and .net **10**, and all passed. — **not
done: verified on net8.0 only** (Server 4710, InformationModel 1099,
Core 4443, plus the client and features alias suites; AOT build clean).
Needs a run against net framework and net10 before this leaves draft.
- [ ] I fixed **all** failing and flaky tests in the CI pipelines and
**all** CodeQL warnings.
- [ ] I have addressed **all** PR feedback received.

### Tests

`tests/Opc.Ua.InformationModel.Tests/Aliasname*Tests.cs` mirror the four
CTT conformance units and no longer `Assert.Ignore` where the CTT
reported failures — the alias suite is 37 tests with no skips. New
`AliasnameOptionalMethodsTests` covers the optional methods, their
reserved NodeIds, the anonymous-caller denial, an add/find/delete round
trip and `LastChange` advancing on mutation.

One pre-existing test changed premise:
`EnumerateSubCategoriesAsyncOnLeafReturnsEmptyAsync` asserted that
`TagVariables` has no sub-categories, which this PR deliberately makes
false. It now targets `Topics` (still a leaf) and a new test guards the
nesting.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: romanett <7413710+romanett@users.noreply.github.com>
Co-authored-by: marcschier <11168470+marcschier@users.noreply.github.com>
2026-08-29 18:05:42 +00:00
..

OPC Foundation UA .NET Standard Reference Server

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 Standard 2.1 or .NET 8.0 and later.

How to build and run the Windows OPC UA Reference Server with UACTT

  1. Open the solution UA.slnx with Visual Studio 2026.
  2. Choose the project Reference Server in the Solution Explorer and set it with a right click as Startup Project.
  3. Hit F5 to 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

  1. Open a command prompt.
  2. Navigate to the folder samples/Reference/ConsoleReferenceServer.
  3. 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:

  • AlarmConditionType
  • DiscrepancyAlarmType
  • LimitAlarmType
  • ExclusiveLimitAlarmType
  • ExclusiveDeviationAlarmType
  • ExclusiveRateOfChangeAlarmType
  • NonExclusiveLimitAlarmType
  • NonExclusiveDeviationAlarmType
  • NonExclusiveRateOfChangeAlarmType
  • DiscreteAlarmType
  • SystemOffNormalAlarmType
  • ExclusiveLevelAlarmType
  • NonExclusiveLevelAlarmType
  • OffNormalAlarmType

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