## Proposed changes Fixes #4857. The stack's log messages wrote network addresses (endpoint, discovery and reverse connect URLs, host names, IP addresses, ports), application and user identities, file paths and exception texts as plain parameters. Applications had no reliable way to keep them out of general-purpose logs. This PR replaces the stack's own redaction mechanism with the standard .NET [data classification and redaction](https://learn.microsoft.com/dotnet/core/extensions/data-redaction) packages. Each sensitive `[LoggerMessage]` parameter is classified. The application decides per classification what reaches its logs: erase it, replace it with an HMAC token so entries stay correlatable, or pass it through. ### Taxonomy `Opc.Ua.Redaction.OpcUaDataClassifications` defines the `OpcUa` taxonomy and one attribute per classification: | Classification | Used for | Parameters | |---|---|---| | `[NetworkAddress]` | URLs, host and domain names, IP/MAC addresses, end points, ports | 120 | | `[ApplicationIdentity]` | certificates, subject, issuer, thumbprint, ApplicationUri | 103 | | `[FilePath]` | file, directory and certificate store paths | 67 | | `[SensitiveText]` | exception or remote-supplied text passed as a parameter | 55 | | `[UserIdentity]` | user names, token subjects | 7 | Correlation ids (`ChannelId`, `SessionId`, ...), status codes and NodeIds stay unclassified. ### Pipeline and defaults - Opc.Ua.Core now references `Microsoft.Extensions.Telemetry(.Abstractions)` 10.11.0, so every project above Core uses the `Microsoft.Gen.Logging` generator. Opc.Ua.Client already did, through Http.Resilience. The packages ship net462 and netstandard2.0 builds, so net48 is supported. - **A plain `ILoggerFactory` logs `(null)` in place of classified values.** Classified values are only written by the redaction-aware logger. - The new `ILoggingBuilder.EnableOpcUaRedaction()` turns that logger on. It is `EnableRedaction()` with the discriminator off; otherwise every unredacted value gets `:ParamName` appended. `AddOpcUa().AddLogging(...)` and `DefaultTelemetry.Create(...)` call it, as do the samples, so they log the same information as before until redactors are registered. - `services.AddOpcUa()` alone does not change the host's logging. Generic-host apps call `builder.Logging.EnableOpcUaRedaction()`. This is documented as a behavior-breaking change in `docs/migrate/2.0.x/telemetry.md`. ### Obsolete API `Redact`, `RedactionWrapper<T>`, `IRedactionStrategy`, `RedactionStrategies` and `SimpleRedactionStrategy` are `[Obsolete]`. They still work, but the stack no longer uses them. ### Not classified - The `Exception` passed to a log call. Applications can drop exception messages with `LoggerEnrichmentOptions.IncludeExceptionMessage`. - Exception and `ServiceResult` message texts. - `ServiceResult`/`StatusCode` parameters and logged data values. - The few log calls whose level is decided at run time. - `Opc.Ua.Vision.OpenUsd`, which references only Opc.Ua.Types and cannot see the attributes. ### Generator behavior differences These are visible to log consumers and to tests: - `IFormattable` values such as `NodeId` are stored in the structured state as invariant strings, not as objects. - The generated log state is a thread-local object that is cleared after the call. - Classified values are pooled redactor objects, valid only during the `Log` call. Tests that inspected log state after the fact now capture it during the call. The shared `RecordingLoggerProvider` snapshots classified values. ## Related Issues - Fixes #4857 ## Types of changes - [ ] Bugfix (non-breaking change which fixes an issue) - [x] Enhancement (non-breaking change which adds functionality) - [ ] Test enhancement (non-breaking change to increase test coverage) - [x] Breaking change (fix or feature that would cause existing functionality to not work as expected; plain logger factories drop classified values) - [x] Documentation Update (if none of the other choices apply) ## Checklist - [x] I have read the CONTRIBUTING doc. - [x] I have signed the CLA. - [x] I ran tests locally with my changes, all passed. - [x] I fixed all failing tests in the CI pipelines. - [x] I fixed all introduced issues with CodeQL and LGTM. - [x] I have added tests that prove my fix is effective or that my feature works and increased code coverage. - [x] I have added necessary documentation (if appropriate). - [ ] Any dependent changes have been merged and published in downstream modules. ## Further comments New tests: - `LogClassificationCoverageTests` (Tools.Tests) scans all 104 stack assemblies and fails if an address, identity or path parameter of a `[LoggerMessage]` method is unclassified. - `DataClassificationLoggingTests` (Core.Tests) pins erasing and HMAC redaction, pass-through, the plain-factory drop, and both stack defaults. Local results on net10.0: | Suite | Passed | Failed | |---|---|---| | Core.Tests | 6,489 | 0 | | Client.Tests | 3,231 | 0 | | Tools.Tests | 7,210 | 0 | | PubSub.Tests | 1,536 | 0 | | Core.Diagnostics.Tests | 571 | 0 | | Configuration.Tests | 241 | 0 | - **Server.Tests:** the full run predates the final test fixes and had 12 failures. All 12 were in the fixtures fixed afterwards, which now pass: RoleStateBinding (45/45) and the FileDirectory and compatibility-logging fixtures (74/74 in total). The full Core.Tests and Server.Tests runs were not repeated after those fixes. - **Builds:** `UA.slnx` builds with 0 errors for net10.0 and net48, and the whitespace check passes. - **NativeAOT:** not confirmed locally, because the machine has no C++ linker. A trimmed publish of `Opc.Ua.Aot.Tests` reported no trim or AOT warnings from the stack, the new packages or the generated logging code; its only errors come from the TUnit test framework (`FSharp.Core` not found). The `aot-test` CI job has to confirm the native build. 🤖 Generated with [Claude Code](https://claude.com/claude-code) --------- Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com> Co-authored-by: Marc Schier <marcschier@users.noreply.github.com>
OPC Foundation UA .NET Standard Reference Server
Introduction
The console reference server can be configured using several console parameters. Some of these parameters are explained in more detail below.
To see all available parameters call console reference server with the parameter -h.
Historical Access
The reference server starts with an in-memory Part 11 historian. Its historized
scalar nodes expose raw, modified, at-time, aggregate, annotation, and update
operations together with populated HistoricalDataConfigurationType
companions. CTT/Historical_KeyValuePairs demonstrates generic
StructuredHistoryData with two KeyValuePair entries at one timestamp. The
CTT notifier exposes historical event read/write bits, a
HistoricalEventConfigurationType companion, and seeded event history.
Writes to the two event-trigger variables report events; live forwarding
completes before the historian snapshots them into its bounded asynchronous
capture queue.
Run the matching client workflow with:
dotnet ConsoleReferenceClient.dll --historian --autoaccept --nosecurity \
opc.tcp://localhost:62541/Quickstarts/ReferenceServer
See docs/HistoricalAccess.md for the
provider contracts, status semantics, and custom storage examples.
Reverse Connect
The OPC UA reverse connect feature allows an OPC UA server to initiate the connection to a client, rather than the traditional model where clients connect to servers. This is particularly useful in scenarios where the server is behind a firewall or NAT, making it difficult for clients to directly connect to it.
How to use Reverse Connect
To enable reverse connect mode, specify the client endpoint URL using the --rc or --reverseconnect parameter:
dotnet ConsoleReferenceServer.dll --rc=opc.tcp://localhost:65300
or
dotnet ConsoleReferenceServer.dll --reverseconnect=opc.tcp://localhost:65300
Example: Server and Client with Reverse Connect
-
Start the client with reverse connect listener on port 65300:
dotnet ConsoleReferenceClient.dll --rc=opc.tcp://localhost:65300 opc.tcp://localhost:62541/Quickstarts/ReferenceServer -
In a separate terminal, start the server with reverse connect to the client:
dotnet ConsoleReferenceServer.dll --rc=opc.tcp://localhost:65300 -a
The server will establish a reverse connection to the client endpoint, and the client will use this connection to communicate with the server.
Additional Options
-aor--autoaccept: Auto accept untrusted certificates (for testing only)-cor--console: Log to console-lor--log: Log app output-tor--timeout: Timeout in seconds to exit application
For the complete list of options, use --help.
X509 user identity certificates
The reference server validates X509 user identity tokens against its trusted-user certificate
store (TrustedUserCertificates, by default %LocalApplicationData%/OPC Foundation/pki/trustedUser).
An untrusted user certificate is rejected with BadIdentityTokenRejected — the --autoaccept option
only auto-accepts the application/channel certificate, never user identity certificates.
To let a trusted client (for example the OPC Foundation Compliance Test Tool) authenticate with an
X509 user token, its user certificate must be present in that store. To make provisioning easy, the
server writes every rejected X509 user certificate to a dedicated review store,
pki/rejectedUser (a sibling of pki/trustedUser). After one failing activation you can move the
legitimate user certificate from pki/rejectedUser/certs into pki/trustedUser/certs (and any
issuing CA into pki/issuerUser/certs) and reconnect. Deliberately-untrusted certificates simply stay
out of the trusted store and continue to be rejected.