3 Commits

Author SHA1 Message Date
romanett 9b034f8291 Enable nullable reference types centrally; migrate all unset and annotations-only projects (#4700)
# Description

Nullable reference types are now enabled once, in `common.props`, and
every project in the repository builds warning-clean with them.

**Configuration**
- `<Nullable>enable</Nullable>` lives in `common.props`. All per-project
`<Nullable>` settings are removed: 178 project files (enable,
annotations, and the `disable` in the three Aot test projects).
- 419 per-file `#nullable enable`/`restore` directives and the 4
`#nullable disable` directives are removed.
- Kept on purpose:
- The 5 `<auto-generated>` schema files (`UANodeSet.cs`, `UA Type
Dictionary.cs`, `OPCBinarySchema.cs`, `SecuredApplication.cs`,
`PInvokeHelper.cs`) keep `#nullable enable`. The compiler ignores the
project setting in generated code, so the directive is required there.
- `tests/Opc.Ua.Interop.LegacyPeer` keeps `disable`. It builds against
the 1.5.378 packages and does not import the repository props.
- `docs/DeveloperGuide.md` and `.github/copilot-instructions.md` now
describe the central setting.

**Migration** (the 43 unset and 13 annotations-only projects, roughly
10k diagnostics)
- **Production code: annotated at the declarations.** Covers
`tools/Opc.Ua.SourceGeneration.Core`, `src/Opc.Ua.Lds.Server` and the
LDS sample.
- Members, parameters and returns are nullable where null actually
flows.
- Null-check helpers carry `[NotNullWhen]` (`IsNull`, `IsValidXmlName`,
`IsMethodTypeDesign`).
- `CoreUtils.Format`, `Utils.Format`, `ITemplateWriter.WriteLine` take
`params object?[]`. `Template.AddReplacement` takes `string?` (rendering
already skips null replacements).
- `IRegisteredServerStore.RegisterAsync` returns
`Task<RegistrationEntry?>`: it returns null when a registration is
removed.
- Dereferences backed by an invariant (for example, the validated model)
use `!`, so runtime behaviour is unchanged.
- **Behavioural changes in production code** (small, deliberate):
- `NodeSetToModelDesign` throws `InvalidOperationException` when the
file is not a NodeSet. Before, it threw a NullReferenceException on the
next line.
- `ModelDesignValidator` starts its lookup tables empty instead of null.
A redundant `if (m_nodes == null) return;` guard is gone.
- **Test code: minimal annotations.**
  - `?` on values that can be null, `!` where the test asserts non-null.
  - `= null!` for fixture members assigned in SetUp.
- `TryGetStructure<T>(out T? x)` where the inferred `T?` broke the
`IEncodeable` constraint.
- A few redundant `== null` checks on structs (`NodeId`, `ArrayOf<T>`)
folded into the adjacent `IsNull`/`Count` checks.

**Notes for reviewers**
- The diff is large (~1,500 files) but almost entirely mechanical: `?`,
`!` and directive removal. The non-annotation changes are listed above.
- Known follow-up, not done here:
`IModelDesign.Namespaces/TargetNamespace/NamespaceUris` stay
non-nullable even though the validator returns null before it loads a
dictionary. Making them nullable would ripple through every generator
call site.

## Related Issues

- Fixes #4439

## Checklist

- [ ] 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.
- [ ] 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.
- [ ] I fixed **all** failing and flaky tests in the CI pipelines and
**all** CodeQL warnings.
- [ ] I have addressed **all** PR feedback received.

The "no new warnings" box covers net10.0 and net48: full non-incremental
builds of `UA.slnx`, `tools/SourceGeneration.slnx`,
`tools/MigrationAnalyzer.slnx` and the Aot test projects finished with 0
warnings and 0 errors under the repository's warnings-as-errors
settings. net9.0 and net8.0 also had no nullable diagnostics, but they
were not rebuilt after the final fixes. Tests have not been run locally
yet.

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

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-08 08:48:13 +02:00
Copilot c03c128384 Treat code analysis (CA) warnings as errors and fix all surfaced analyzer warnings (#4680)
# Description

`TreatWarningsAsErrors` was already enabled, but
`CodeAnalysisTreatWarningsAsErrors` was `false`, so Microsoft Code
Analysis (`CAxxxx`) warnings were non-fatal. This PR sets it to `true`
in `common.props` and fixes all 55 analyzer warnings the net10.0 build
reported.

**Production code**
- `SamplingGroup.cs`: CA2213 is a false positive here because the
detached `CancellationTokenSource` is disposed by `CancelSamplingLoop`
once the loop completes. It is suppressed with a pragma, a justification
and a TODO, following the existing pattern in
`ServerBase.RequestQueue.cs`.

**Tests**
- CA1861: constant array arguments are moved to `static readonly` fields
or replaced with `ArrayOf<T>` collection expressions. In the legacy
interop server I used locals instead, because those arrays become node
values that writes can change in place.
- CA2025: tasks that finish before disposal (`Assert.ThrowsAsync`, or
awaited before `using` scope exit) are suppressed with justification
comments, following existing test patterns.
- CA1812: classes created by the DI container are suppressed with a
comment and a TODO.
- CA2208: benchmark switch defaults now throw
`InvalidOperationException`.
- CA1845: `Substring(0, 8)` is replaced with `[..8]`.
- CA1307: `string.Replace` is replaced with `Split`/`Join`, which also
works on net48.
- CA5394: `Random` is replaced with `RandomNumberGenerator`.

**Docs**
- `docs/DeveloperGuide.md` now says CA warnings also fail the build, and
that any suppression needs a comment explaining why plus a TODO.

**Validation**
- I fixed the 55 warnings from a net10.0 build of `UA.slnx`
(`CustomTestTarget=net10.0`). That build ran before the setting was
turned on, and I have not rebuilt net10.0 since the fixes.
- `CustomTestTarget=net48` build of `UA.slnx`: 0 warnings, 0 errors.
- I also started a full build across all target frameworks with the
setting on. Its log showed no errors or warnings while it ran, but I
couldn't read its final result.
- No tests have been run yet; CI should confirm the multi-TFM build and
the tests.

## Related Issues

- N/A

## Checklist

- [ ] 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.
- [ ] 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.
- [ ] 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.
- [ ] I fixed **all** failing and flaky tests in the CI pipelines and
**all** CodeQL warnings.
- [ ] I have addressed **all** PR feedback received.

---------

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: Marc Schier <marcschier@users.noreply.github.com>
2026-10-06 18:54:28 +02:00
romanett ce88955f70 Harden encoders/decoders against untrusted input and align them with Part 6 / Part 14 (#4599)
# Description

Hardens the encoders and decoders against untrusted input and aligns
them with OPC 10000-6 (1.05) and OPC 10000-14. This comes from an audit
of every codec reachable from a peer:
- Binary, JSON and XML decoders and encoders;
- built-in and complex types;
- UA-TCP/UASC framing;
- PubSub UADP and PubSub JSON.

The audit found 97 issues: 1 critical, 7 high, 39 medium and 50 low.
They are all fixed here, one commit per finding (IDs B1-, J1-, X1-, T1-,
S1-, U1-, P1-, E1-, E2- in the commit subjects). Every fix was then
checked against the spec a second time, and the deviations that re-check
found were fixed as well (`*-spec` commits).

## Security (decoders reachable from unauthenticated peers)

- **Allocation from length prefixes (B1-1, B1-5, U1-1, U1-3).**
- Array, string and byte-string lengths are checked against the bytes
left in the message before anything is allocated.
- Arrays read element by element grow as elements are decoded, so nested
length prefixes can no longer multiply memory.
- UADP discovery counts and chunk reassembly buffers are bounded the
same way.
- **Stack exhaustion.** Nesting is checked for remaining stack
(`RuntimeHelpers.EnsureSufficientExecutionStack` mapped to
`BadEncodingLimitsExceeded`), and the large Variant read/write methods
were split into scalar, array and matrix methods. Measured on 1 MB and
256 KB threads, no codec overflows at the default limits any more.
- **XML element depth (X1-1).** XmlElement values and raw
ExtensionObject bodies are copied node by node with a depth limit,
instead of with the recursive `InnerXml`, `ImportNode`, `InnerText` and
`DeepEquals` calls.
- **Limit bypasses:**
- JSON NodeId, QualifiedName and opaque strings now respect
MaxStringLength and MaxByteStringLength (J1-1).
  - Matrix rank is limited to 32.
  - Decimal size is bounded (T1-3).
  - XML base64 is checked before it is decoded.
  - XML arrays are checked before each element is read.
- **CPU and algorithmic cost:**
- UADP reassembly uses an O(1) overlap check with a per-message chunk
cap (U1-2).
  - PubSub JSON matches fields to metadata through a name index (P1-2).
  - LocalizedText "mul" text is parsed lazily (T1-5).
- Unknown SecurityTokenIds trigger a throttled background SKS refresh
instead of an inline call per datagram (U1-9).
- **PubSub metadata poisoning (P1-1).** Inbound metadata is registered
only for identities a configured reader expects, is capped, and an
unauthenticated message can no longer pin a version.
- **Exception contract.** Decoders fail with `ServiceResultException`
(BadDecodingError / BadEncodingLimitsExceeded) instead of letting
ArgumentException, InvalidOperationException, TypeLoadException and
similar escape.
- **UASC (S1-*):**
  - OPN and CLO must be single final chunks.
  - The certificate of an unsigned OPN is ignored.
  - The padding and ExtraPadding bytes are validated.
- A renewed token is activated only after a chunk has been verified with
it.
- A policy change on renewal is rejected before the channel certificate
is touched.
  - Secured chunk length arithmetic is bounded.

## Wire-visible behaviour changes

All follow the spec exactly; there is no reader for the old forms unless
noted.

- **UA Binary:**
  - Variant type ids 26-31 decode as ByteString.
- Picoseconds without their timestamp are ignored, and values of 10000
and above are clamped to 9999.
- A Null-type Variant with the array flag consumes its length and
dimensions.
- **UA JSON:**
- Messages are ExtensionObjects with the body inline; there is no
`UaBody` envelope any more (5.4.9 / 5.4.2.16).
- The Variant `Value` is omitted exactly for NULLs of nullable types
(Table 41).
  - RawData keeps nested UaType/UaTypeId and the StatusCode Symbol.
  - Duplicate member names are rejected.
  - `{}` decodes as a null ExtensionObject.
- Numbers and identifiers are parsed strictly and culture-independently.
  - QualifiedName follows 5.4.2.14.
  - Opaque bodies of known types carry the DataType id.
  - Enumerations without a literal are written as the number.
- **UA XML:**
  - The earliest DateTime is written as `0001-01-01T00:00:00Z`.
- Null typed scalars and null array elements are written with `xsi:nil`.
  - An ExtensionObject without a body has no `Body` element.
  - Strings XML cannot represent are rejected.
- Only the xs:dateTime and xs:date forms are accepted; a value without a
zone is still read as UTC, because published model files use it.
  - Only the Part 6 Guid form is accepted.
  - Booleans are case-sensitive in XmlDecoder.
- **UA-TCP:**
- OPNC/OPNA/CLOC/CLOA fault the channel. Older releases that split a
long-chain OPN into chunks are rejected, so this needs a release note.
  - The sender truncates the certificate chain to fit a single chunk.
  - The received certificate chain is sized from the chunk size.
- Hello buffer sizes down to 1024 bytes are honoured; below that, an ERR
with Bad_TcpInternalError is sent.
- A 4096-byte Error reason is accepted, and the SecurityPolicyUri limit
is 255 bytes.
- **PubSub UADP:**
- Chunk NetworkMessages use the Part 14 7.2.4.4.4 layout, and each chunk
is secured on its own with its own sequence number.
  - The Sizes array is part of the secured payload.
- Padded RawData keeps its length prefix, and null values are written as
-1.
  - DataSetMessages with the valid bit clear are skipped.
  - Null discovery arrays are accepted.
- **PubSub JSON:**
- Variants use `UaType`/`Value`, with the 7.2.5.4.2 top-level collapse.
The deprecated `Type`/`Body` form is still read.
- Status is written as a `{Code,Symbol}` object; a numeric Status is
still accepted.
  - Discovery messages follow Tables 188-192, with GUID MessageIds.
  - Enumeration fields are written as `Name_Value`.
  - Fields appended with a MinorVersion bump are accepted.

## Known deviations and limitations (documented, not changed)

- A known type whose ExtensionObject XML body fails to decode fails the
message, like a failing binary body. 5.2.2.15 only says the decoder
*should* continue, and continuing reopens the log-flooding path.
- Reserved Variant type ids 26-31 are passed to the application as
ByteString without the raw type id.
- JSON UaTypeId of an opaque body of an *unknown* type stays the
encoding id, because no type system is available to map it.
- PubSub JSON encoder:
- Structure fields without a subtype are still wrapped with a UaType,
and concrete multi-dimensional or abstract-rank fields still carry a
UaType (Table 186).
- Namespace-0 enumerations without EnumDataTypes are written as a
numeric string.
- Chunked transcoded frames have no writer group, so their sequence
numbers continue from the source number.
- Pre-existing and out of scope: the HTTPS JSON binding uses
Content-Type `application/opcua+uajson`, while 1.05 7.4.5 requires
`application/json`.

## Tests

- Every fix has a regression test.
- Tests that pinned non-conformant behaviour were updated, and their
commit messages say so.
- Fuzz seeds were regenerated where the wire changed.

Local results:
net10.0, 27 suites green (Types 11354, Core.Encoders 2933, Encoders.Fuzz
8112, Core 5955 + 1 known intermittent ActivityTraceFlags metrics test
that passes alone, Client 2732, Server 7802, Sessions 790, GDS 1234,
Subscriptions 641, SourceGeneration.Core 4266, PubSub 1490 and all
PubSub transport suites). Full UA.slnx build 0 warnings / 0 errors on
net10.0 and net48.

## Related Issues

- Follow-up: #4598 (possible throughput regression of per-element binary
array reads).

## 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. (net10.0
suites run; net48 build only)
- [ ] I fixed **all** failing and flaky tests in the CI pipelines and
**all** CodeQL warnings.
- [ ] I have addressed **all** PR feedback received.

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

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-01 05:12:47 +00:00