HistorianSspiClient rewritten on top of System.Net.Security.NegotiateAuthentication
in place of P/Invoke into secur32.dll's InitializeSecurityContextW. The class
keeps the same Next() / Dispose() / two-constructor surface so callers don't
change. RequiredProtectionLevel=EncryptAndSign + AllowedImpersonationLevel=
Identification produces a request-flag set equivalent to the captured native
0x2081C / 0x81C bitmasks (still preserved as constants for the existing unit
tests). Removes the only Windows P/Invoke in the production SDK; the
[SupportedOSPlatform("windows")] gating elsewhere stays in place pending a
separate sweep.
HistorianStorageType (Cyclic = 1, Delta = 2):
Captured 2026-05-04 via --write-storage-type on the harness. Delta differs
from Cyclic in three places — header byte 10 (0x02 -> 0x06), flag-block
byte 1 (0x01 -> 0x02), and 4 zero bytes inserted after StorageRate before
the FILETIME. Server persists Tag.StorageType=1/2 accordingly. Plumbed
through HistorianTagDefinition.StorageType + serializer + orchestrator + 2
new tests (golden bytes + live SQL persistence verification).
Docs polish:
CLAUDE.md no longer claims "no P/Invoke" (HistorianSspiClient is the one
allowed P/Invoke surface); updated test count to 169+; AGENTS.md Required
SDK Surface and Repository Layout brought up to date with the live state
including the write surface; handoff.md "not a git working tree" obsolete
note removed.
171/171 tests pass with the NegotiateAuthentication replacement (was 169;
+2 new tests for StorageType).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
ApplyScaling (HistorianTagDefinition.ApplyScaling):
The EnsT2 trailer's second byte controls server-side scaling — `FE 00`
mirrors MinRaw to MinEU and sets AnalogTag.Scaling=0; `FE 01` persists
distinct MinRaw/MaxRaw and sets Scaling=1. Decoded by toggling
set_ApplyScaling on the native harness and capturing the wire bytes for
both values with identical inputs. The earlier docs claimed
EnsureTagAsync needed a follow-up "UpdateTags" call; the WCF surface has
no such operation — toggling that one byte is the whole fix.
StorageRate (HistorianTagDefinition.StorageRateMs):
Serializer accepts a non-default rate, validated empirically against
the live server which only accepts quantized values
(1000/5000/10000/60000/300000 ms).
EnsureTagAsync upsert semantics:
Second call on the same tag name with different fields succeeds and
updates Description, MinEU, MaxEU, MinRaw, MaxRaw, Scaling in place
(verified by direct SQL inspection in a live test).
Plan + doc closeout:
write-commands-reverse-engineering.md rewritten as a current-state
plan with three workstreams (A doc closeout / B idempotency / C1
StorageRate) and a parallelism table; prior phase notes preserved as
appendix. handoff.md, implementation-status.md, wcf-contract-evidence.md,
README.md updated to remove "writes are out of scope" / non-existent
UpdateTags references and document the actual EnsT2 wire format
including the `FE xx` trailer.
Reverse-engineering harness gains --write-apply-scaling and a SQL
post-check that prints the persisted AnalogTag bounds so future RE
sessions can verify wire→DB causality without leaving the harness.
169/169 tests pass (was 165; +4 new tests covering ApplyScaling,
StorageRate golden bytes, StorageRate live persistence, and
EnsureTagAsync upsert semantics).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Full read-only SDK (src/AVEVA.Historian.Client) implementing the CLAUDE.md required
surface against AVEVA Historian's binary WCF protocol — no native AVEVA runtime
dependency. All operations live-verified against a local Historian:
- ProbeAsync, ReadRawAsync, ReadAggregateAsync, ReadAtTimeAsync, ReadEventsAsync
- BrowseTagNamesAsync, GetTagMetadataAsync (17 native data-type codes mapped)
- GetConnectionStatusAsync, GetStoreForwardStatusAsync, GetSystemParameterAsync
- 108/108 unit + integration tests pass
Includes the reverse-engineering toolkit (tools/AVEVA.Historian.ReverseEngineering)
used to decode the protocol: WCF probes, IL inspection via dnlib, and IL-rewrite
instrumentation (instrument-wcf-{write,read}message etc.) plus the .NET Framework
trace harness (tools/AVEVA.Historian.NativeTraceHarness) for parity testing.
Sanitized handoff evidence under docs/reverse-engineering/. Native AVEVA binaries
(current/, aveva-install-x64/, aveva-install-x86/) are gitignored — fetch separately
from the AVEVA installer.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty