2 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
romanett	52f8520baa	Detect resource and limit abuse in the encoder/decoder fuzz harness (#4666) ... ## Why The encoder/decoder fuzz targets only flagged crashes, unhandled exceptions and encoding-fidelity mismatches. They could not observe a decode that stays within the exception contract but consumes far more memory, CPU or stack than its input justifies, or that materialises values larger than the context's encoding limits. None of the resource-related findings of the codec audit would have been caught. ## What Adds four shared oracles to the fuzz harness (`fuzzing/Common/Fuzz/FuzzOracles*.cs`), applied by every host (libFuzzer, AFL, `--replay`, Tools playback and the NUnit replay): - **Allocation** — wraps the Binary/JSON/XML decode cores, the built-in-type targets, the PubSub UADP/JSON decoders and the UADP reassembler; fails when a decode allocates more than `64x` its input plus `8 MB`, whether it returns or throws. Uses the per-thread allocation counter (the AppDomain counter on .NET Framework). - **Time** — a per-input budget of `1 s + 100 ms/KB`, re-run twice and reported only if the fastest run is still over, so JIT/GC/CI noise does not trip it (`OPCUA_FUZZ_TIME_BUDGET_SCALE`, `0` disables). - **Stack** — every input runs on a worker thread with a `256 KB` stack, so recursion that comes close to the limit of a normal thread is caught in-process as a crash rather than near 200 levels. `StackTestcases` inputs replay through every target in a child process (`--fuzz-replay-all`), since such a crash cannot be caught. - **Decoded limits** — walks a decoded value for strings, identifiers, ByteStrings and arrays beyond the context's `MaxStringLength`/`MaxByteStringLength`/`MaxArrayLength`; matrices are additionally boxed the legacy way so a value no consumer can materialise is reported. The fuzz context uses `4096/8192/4096` so small inputs reach the limits. Supporting changes: - `ArrayOf<T>`/`MatrixOf<T>` are not `IEnumerable`, so the limit walker unpacks them via `ToArray`/`ToArrayOf` (otherwise it silently traversed nothing). - `Decimal` is registered in the fuzz context so the targets exercise `Decimal.Decode`. - **B1-2 bug fix**: `BinaryDecoder.ReadExtensionObject` dereferenced a null element for an XML body that is not an element; now rejected with `BadDecodingError`. Found by replaying the nightly crash corpus under the new exception contract; 5 corpus inputs are added as gating reproducers. - Reproducers for B1-1, T1-3, X1-1 and U1-3, built in process by documented builders (`ResourceReproducerTests`, `PubSubReproducerTests`) and checked in to the corpus, where every target replays them under the oracles. Each was verified by reverting the matching fix locally and confirming the guard fires (e.g. B1-1 then allocates ~21 MB from 481 input bytes). - `Fuzzing.md` / `CrashCorpus.md` document the oracles and the private-input log policy. ## Testing Green on net10.0 and net48: | Suite | net10.0 | net48 | |---|---|---| | `Opc.Ua.Encoders.Fuzz.Tests` | 8130 | 8130 | | `Opc.Ua.PubSub.Fuzz.Tests` | 149 | n/a (modern-only) | | `Opc.Ua.Fuzzing.Tests` | 154 | 154 | | `Opc.Ua.Types.Tests` (encoders) | 3698 | builds | Also verified: `Network`/`Certificates` fuzz test suites, all fuzz hosts and Tools projects build, the fuzz manifest validator passes, `dotnet format whitespace` is clean, and the full ~22k-input nightly crash corpus replays with no oracle false positives. Stacked on `romanett/encoder-decoder-spec-security-83c9f5`. 🤖 Generated with [Claude Code](https://claude.com/claude-code) --------- Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-04 19:16:23 +00:00