Joseph Doherty
f32fd57874
Two cleanups from the post-EnsureTagAsync punch list — both isolated, no protocol discovery required. #89 dead code in Historian2020ProtocolDialect: - BrowseTagNamesAsync and GetTagMetadataAsync on the dialect both threw ProtocolEvidenceMissingException, but HistorianClient routes those calls directly to HistorianWcfTagClient — the dialect overrides were never reached. Removed both methods. ReadBlocksAsync stays (it's a deliberate guardrailed entry on the public surface). #90 explicit-creds tag-metadata path: - HistorianWcfTagClient.WcfRetrievalSession.ValidateSupportedAuth threw ProtocolEvidenceMissingException whenever IntegratedSecurity=false AND UserName/Password were supplied. But the surrounding code already wires those creds through ApplyWindowsCredential -> factory.Credentials.Windows.ClientCredential — the validator was just being conservative about an untested combination. - Inverted the check: now only rejects the no-auth-at-all combination (IntegratedSecurity=false + no UserName + no Password). The other three valid auth shapes pass through to WCF. Tests: 161 -> 163 (+2). New unit test verifies the no-auth case still throws; new gated live integration test GetTagMetadataAsync_ExplicitCredentials_AgainstLocalHistorian exercises the explicit-creds path when HISTORIAN_USER+HISTORIAN_PASSWORD are set, skips cleanly otherwise. CLAUDE.md updated: removed the two now-resolved entries from "Remaining gaps"; explicit-creds line refined to note the live-verification env-var requirement. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
126 lines
11 KiB
Markdown
126 lines
11 KiB
Markdown
# CLAUDE.md
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This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
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## Mission
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Build a fully managed .NET 10 replacement for AVEVA Historian's `aahClientManaged` / `aahClient.dll` stack by reverse-engineering the proprietary binary protocol. The production SDK under `src/AVEVA.Historian.Client/` must remain pure managed .NET 10 — no P/Invoke, no native AVEVA runtime dependency, no REST. Tools under `tools/` and scripts under `scripts/` are reverse-engineering aids only.
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Read `AGENTS.md` (standing constraints), `instructions.md` (decision record), and `docs/reverse-engineering/handoff.md` (current evidence + active blocker) before starting non-trivial work. The handoff doc is the entry point — it tracks the live blocker, next pickup steps, and the canonical list of primary reference docs.
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## Required SDK Surface
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Reads (the original required surface, all working live as of 2026-05-04):
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- `ProbeAsync`, `ReadRawAsync`, `ReadAggregateAsync`, `ReadAtTimeAsync`, `ReadEventsAsync`
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- `BrowseTagNamesAsync`, `GetTagMetadataAsync`
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- Status helpers: `GetConnectionStatusAsync`, `GetStoreForwardStatusAsync`, `GetSystemParameterAsync`
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Writes (added 2026-05-04 by explicit user request — do not extend further without one):
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- `EnsureTagAsync` for analog types: Float, Double, Int2, Int4, UInt4 (live-verified end-to-end). Other types (SingleByteString/DoubleByteString/Int1/Int8/UInt8) fail at native AddTag — likely require a different path and are intentionally not supported. `MinEU`/`MaxEU` round-trip correctly into the DB; `MinRaw`/`MaxRaw` are sent on the wire but the server mirrors them to MinEU/MaxEU when ApplyScaling=false (verified against native — server quirk, not SDK bug).
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- `DeleteTagAsync`
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`AddS2` (write samples) is architecturally blocked — server cache only ingests from configured IOServers/ApplicationServer pipelines. Do not add write-samples support.
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Methods without protocol evidence currently throw `ProtocolEvidenceMissingException` from `Historian2020ProtocolDialect`. Do not stub fake behavior — leave them throwing until evidence supports an implementation.
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## Build & Test
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```powershell
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dotnet build .\Histsdk.slnx --no-restore
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dotnet test .\Histsdk.slnx --no-build --logger "console;verbosity=minimal"
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```
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Run a single test:
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```powershell
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dotnet test .\Histsdk.slnx --no-build --filter "FullyQualifiedName~WcfDataQueryProtocolTests"
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```
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Live integration tests in `tests/AVEVA.Historian.Client.Tests/HistorianClientIntegrationTests.cs` are gated and skip cleanly without these env vars:
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```powershell
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$env:HISTORIAN_HOST, $env:HISTORIAN_PORT (32568), $env:HISTORIAN_USER, $env:HISTORIAN_PASSWORD,
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$env:HISTORIAN_TEST_TAG, $env:HISTORIAN_TAG_FILTER
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```
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Never write real credentials, hostnames, user names, or customer tag names into docs, scripts, captures, or commit messages.
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## Reverse-Engineering CLI
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`tools/AVEVA.Historian.ReverseEngineering` is the .NET 10 CLI for static inspection, WCF probes, and IL-rewrite instrumentation. Common entry points:
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```powershell
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dotnet run --no-build --project tools\AVEVA.Historian.ReverseEngineering -- wcf-probe $env:HISTORIAN_HOST 32568
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dotnet run --no-build --project tools\AVEVA.Historian.ReverseEngineering -- wcf-cert-probe $env:HISTORIAN_HOST 32568 localhost
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dotnet run --no-build --project tools\AVEVA.Historian.ReverseEngineering -- wcf-like-tag-browse $env:HISTORIAN_HOST 32568 $env:HISTORIAN_TAG_FILTER
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dotnet run --no-build --project tools\AVEVA.Historian.ReverseEngineering -- wcf-start-query $env:HISTORIAN_HOST 32568 $env:HISTORIAN_TEST_TAG --max-attempts 1 --timeout-seconds 3
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dotnet run --project tools\AVEVA.Historian.NativeTraceHarness -- --scenario history --tag $env:HISTORIAN_TEST_TAG --lookback-minutes 1440
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```
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The `wcf-start-query` matrix is expensive — always pass `--max-attempts` / `--timeout-seconds` for negative probes. See `docs/reverse-engineering/capture-workflow.md` for the full repeatable capture sequence (manifest, mark, exports, Frida winsock attach, etc.).
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## Code Architecture
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### Production SDK (`src/AVEVA.Historian.Client/`)
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Three layered subsystems, intentionally decoupled so protocol parsing can be unit-tested without a live server:
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- **`HistorianClient` + `HistorianClientOptions`** — public façade. Validates inputs, delegates reads to `Historian2020ProtocolDialect`, delegates probe/tag-metadata/browse to the WCF layer.
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- **`Wcf/`** — managed WCF/MDAS layer. The Historian uses Net.TCP on port `32568` with a custom `application/x-mdas` content type wrapping a binary SOAP 1.2 / WS-Addressing 1.0 envelope. `MdasMessageEncoder` + `MdasMessageEncodingBindingElement` implement that wrapper. `HistorianWcfBindingFactory` produces three flavors: plain MDAS, MDAS+Windows transport (used for `/Hist-Integrated`), and MDAS+certificate (used for `/HistCert`). Service paths live in `HistorianWcfServiceNames`. WCF data contracts (`Wcf/Contracts/`) are reproduced from server-side static analysis and are versioned per native interface (e.g., `IRetrievalServiceContract2..4`).
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- **`Protocol/`** — binary frame layer (`HistorianFrameReader`/`Writer`, `HistorianBinaryPrimitives`, `HistorianMessageType`). `Historian2020ProtocolDialect` is the version-anchored bridge between `HistorianClient` and the frame layer; methods without sufficient evidence throw `ProtocolEvidenceMissingException` rather than guessing wire bytes.
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- **`Transport/`** — pluggable `IHistorianTransport` (default: TCP). Tests inject a fake transport.
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- **`Models/`** — public DTOs and enums (`HistorianSample`, `RetrievalMode`, etc.). `HistorianDataValue` represents the discriminated value type.
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`InternalsVisibleTo` exposes internals to the test assembly and the reverse-engineering tool.
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### Read-path status (resolved 2026-05-04)
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The original blocker — `Open2` reaching server logic but `Retr.StartQuery2` returning false with empty buffers — is **resolved**. Root causes were:
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1. WCF parameter-name mismatches — server contracts use `inBuff`/`outBuff`/`pRequestBuff`/etc.; the SDK's default C#-derived names made the deserializer ignore the body. Fixed via `[MessageParameter(Name = "...")]` attributes across `IHistoryServiceContract2`, `IRetrievalServiceContract2..4`, `IStatusServiceContract2`, `ITransactionServiceContract`.
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2. Native SSPI request flags — round 0 = `0x2081C` (adds `IDENTIFY` + `REPLAY_DETECT` + `SEQUENCE_DETECT`); rounds 1+ = `0x81C`. Without `REPLAY_DETECT|SEQUENCE_DETECT`, NTLM MIC generation is skipped and `AcceptSecurityContext` rejects round 1. Implemented in `HistorianSspiClient` via P/Invoke `InitializeSecurityContextW`.
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3. Cross-service version probes (`Trx/GetV`, `Stat/GetV`, `Retr/GetV`) between RTag2 and EnsT2 in the event flow — required to register the client with each service's session table.
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End-to-end chain working from a pure managed .NET 10 client: `Hist.GetV → Hist.ValCl × N → Hist.Open2 → /Retr.GetV → Retr.IsOriginalAllowed → Retr.StartQuery2 → loop Retr.GetNextQueryResultBuffer2`. 23 live integration tests against `localhost` cover all required reads + the two write ops.
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### Write-path notes (added 2026-05-04)
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`EnsureTagAsync` and `DeleteTagAsync` chain follow the same pattern as reads but require Open2 with `NativeIntegratedWriteEnabledConnectionMode = 0x401` (Process | Write | IntegratedSecurity) — the read-path's `0x402` (read-only) makes the server return err 132 `OperationNotEnabled` silently. The analog Float `CTagMetadata` payload is 144 bytes with a leading `0x4E` marker byte and a 2-byte trailer `FE 00`. See `docs/reverse-engineering/handoff.md` and the `WriteDiag` env-gated diagnostic helper in `HistorianWcfTagWriteOrchestrator` for capture details.
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### Remaining gaps
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Smaller, isolated items — none block the production read surface:
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- Remote TCP transports (`RemoteTcpIntegrated`, `RemoteTcpCertificate`) untested against an actual remote Historian (tests skip without `HISTORIAN_REMOTE_TCP_HOST`).
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- Explicit username/password tag-metadata path is wired (validator only blocks no-auth-at-all), but live-verification requires `HISTORIAN_USER`+`HISTORIAN_PASSWORD` set; gated test `GetTagMetadataAsync_ExplicitCredentials_AgainstLocalHistorian` skips otherwise.
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- Per-row trailing ~24 bytes of `GetNextQueryResultBuffer` are not decoded (likely per-sample value/source/state metadata).
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- `EnsureTagAsync` distinct `MinRaw`/`MaxRaw` persistence requires `ApplyScaling=true` + a follow-up `UpdateTags` call — not yet wired (no API user has asked).
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### Tools Layer
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- `tools/AVEVA.Historian.NativeTraceHarness/` — **.NET Framework** (not .NET 10) harness that loads `current/aahClientManaged.dll` and records sanitized reflection snapshots around `OpenConnection`, `StartQuery`, `MoveNext`. Exists specifically to parity-test against the native wrapper.
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- `tools/AVEVA.Historian.NetFxWcfProbe/` — .NET Framework WCF probe to rule out .NET 10-only WCF behavior differences.
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- `tools/AVEVA.Historian.ReverseInstrumentation/` — assembly injected into IL-rewritten copies of `aahClientManaged.dll` for sanitized logging. Rewrites land in `docs/reverse-engineering/dnlib-write-copy/`, never in `current/`.
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- `tools/AVEVA.Historian.WcfCaptureServer/` — fake server for endpoint experiments.
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- `scripts/` — PowerShell + Frida runners for native attach captures (winsock, system boundary, runtime pointers, ValCl SSPI context).
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### Evidence & Artifacts
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- `docs/reverse-engineering/` — sanitized Markdown summaries + small JSON evidence. Always commit-safe.
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- `artifacts/reverse-engineering/` — raw / identity-bearing runtime output. Never committed; never copy contents into `docs/` without sanitizing.
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- `fixtures/protocol/` — sanitized golden byte fixtures, named to match `manifest` scenarios.
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- `current/` and `aveva-install-{x64,x86}/` — AVEVA binaries. **Never modify, delete, or redistribute.** Use `current/` first because it matches the deployed sidecar.
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## Testing Conventions
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Unit tests are golden-byte and round-trip oriented — `WcfDataQueryProtocolTests`, `WcfEventQueryProtocolTests`, `WcfTagQueryProtocolTests`, `WcfOpen2ProtocolTests`, `FrameTests`, `BinaryPrimitiveTests`. `ProtocolGuardrailTests` enforces that unimplemented methods throw `ProtocolEvidenceMissingException` rather than returning empty results. When adding a new protocol code path, add a golden-byte fixture before/alongside the implementation.
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## Safety
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- Never commit credentials, hostnames, user names, customer tag names, or raw packet captures. Use placeholders in docs.
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- Run a sanitization scan after touching auth/capture docs (the rg pattern is in handoff.md "Next Pickup Steps").
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- Production code under `src/` must remain pure managed .NET 10 with no native AVEVA reference. Reverse-engineering harnesses under `tools/` may reference native binaries.
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- This workspace IS a Git working tree (origin: gitea.dohertylan.com). Use normal git workflow; the prior note about "no working tree, track via timestamps" is obsolete.
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