Initial project state: .NET reference, design, Rust port (M0+M1), evidence

Layout:
- src/                    .NET 10 x64 reference: MxNativeCodec, MxNativeClient,
                          MxAsbClient, probes, tests, harnesses. Executable spec.
- design/                 Architectural plan for the Rust port (M0–M6), error
                          model, protocol invariants, risks (R1–R16), adversarial
                          review log (review.md).
- rust/                   Rust workspace. M0 skeleton + M1 codec parity.
                          mxaccess-codec: 215 unit tests + 2 cross-implementation
                          parity tests (byte-identical against .NET reference).
                          Other crates are M0 stubs awaiting M2+.
- captures/               Frida + netsh + pcap evidence per CLAUDE.md
                          ("captures are evidence, not throwaway logs").
- analysis/               Decompiled C# (frida/proxy/decompiled-*),
                          Ghidra exports for native DLLs (`exports/` only —
                          working state at `projects/` and AVEVA's input
                          binaries at `input/` are gitignored).
- docs/                   Reverse-engineering reference docs.
- tools/                  Setup-LiveProbeEnv.ps1 (Infisical credential fetcher),
                          Compute-Crc.ps1 (.NET parity helper).
- .github/workflows/      Rust CI: fmt + build + test + clippy on Windows.
- LICENSE                 MIT (Joseph Doherty, 2026).

Verified:
- cargo test --workspace → 217 passed (215 unit + 2 .NET parity), 0 failed
- cargo clippy --workspace -- -D warnings → clean
- cargo fmt --all -- --check → clean
- cargo publish --dry-run -p mxaccess-codec → packages cleanly

Excluded from history (see .gitignore):
- **/bin, **/obj, **/target — build artifacts
- analysis/ghidra/projects/ — Ghidra working state (regenerable)
- analysis/ghidra/input/ — AVEVA proprietary DLLs (vendor IP)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

analysis/decompiled/aaServicesContractIAuthenticateASB/Invensys.Compression/AADeflaterManaged.cs

@@ -0,0 +1,188 @@
+using System;
+
+namespace Invensys.Compression;
+
+internal class AADeflaterManaged : IDisposable
+{
+	private enum DeflaterState
+	{
+		NotStarted,
+		SlowDownForIncompressible1,
+		SlowDownForIncompressible2,
+		StartingSmallData,
+		CompressThenCheck,
+		CheckingForIncompressible,
+		HandlingSmallData
+	}
+
+	private const int MinBlockSize = 256;
+
+	private const int MaxHeaderFooterGoo = 120;
+
+	private const int CleanCopySize = 8072;
+
+	private const double BadCompressionThreshold = 1.0;
+
+	private AAFastEncoder deflateEncoder;
+
+	private AACopyEncoder copyEncoder;
+
+	private AADeflateInput input;
+
+	private AAOutputBuffer output;
+
+	private DeflaterState processingState;
+
+	private AADeflateInput inputFromHistory;
+
+	internal AADeflaterManaged()
+	{
+		deflateEncoder = new AAFastEncoder();
+		copyEncoder = new AACopyEncoder();
+		input = new AADeflateInput();
+		output = new AAOutputBuffer();
+		processingState = DeflaterState.NotStarted;
+	}
+
+	public bool NeedsInput()
+	{
+		if (input.Count == 0)
+		{
+			return deflateEncoder.BytesInHistory == 0;
+		}
+		return false;
+	}
+
+	public void SetInput(byte[] inputBuffer, int startIndex, int count)
+	{
+		input.Buffer = inputBuffer;
+		input.Count = count;
+		input.StartIndex = startIndex;
+		if (count > 0 && count < 256)
+		{
+			switch (processingState)
+			{
+			case DeflaterState.NotStarted:
+			case DeflaterState.CheckingForIncompressible:
+				processingState = DeflaterState.StartingSmallData;
+				break;
+			case DeflaterState.CompressThenCheck:
+				processingState = DeflaterState.HandlingSmallData;
+				break;
+			}
+		}
+	}
+
+	public int GetDeflateOutput(byte[] outputBuffer)
+	{
+		output.UpdateBuffer(outputBuffer);
+		switch (processingState)
+		{
+		case DeflaterState.NotStarted:
+		{
+			AADeflateInput.InputState state3 = input.DumpState();
+			AAOutputBuffer.BufferState state4 = output.DumpState();
+			deflateEncoder.GetBlockHeader(output);
+			deflateEncoder.GetCompressedData(input, output);
+			if (!UseCompressed(deflateEncoder.LastCompressionRatio))
+			{
+				input.RestoreState(state3);
+				output.RestoreState(state4);
+				copyEncoder.GetBlock(input, output, isFinal: false);
+				FlushInputWindows();
+				processingState = DeflaterState.CheckingForIncompressible;
+			}
+			else
+			{
+				processingState = DeflaterState.CompressThenCheck;
+			}
+			break;
+		}
+		case DeflaterState.CompressThenCheck:
+			deflateEncoder.GetCompressedData(input, output);
+			if (!UseCompressed(deflateEncoder.LastCompressionRatio))
+			{
+				processingState = DeflaterState.SlowDownForIncompressible1;
+				inputFromHistory = deflateEncoder.UnprocessedInput;
+			}
+			break;
+		case DeflaterState.SlowDownForIncompressible1:
+			deflateEncoder.GetBlockFooter(output);
+			processingState = DeflaterState.SlowDownForIncompressible2;
+			goto case DeflaterState.SlowDownForIncompressible2;
+		case DeflaterState.SlowDownForIncompressible2:
+			if (inputFromHistory.Count > 0)
+			{
+				copyEncoder.GetBlock(inputFromHistory, output, isFinal: false);
+			}
+			if (inputFromHistory.Count == 0)
+			{
+				deflateEncoder.FlushInput();
+				processingState = DeflaterState.CheckingForIncompressible;
+			}
+			break;
+		case DeflaterState.CheckingForIncompressible:
+		{
+			AADeflateInput.InputState state = input.DumpState();
+			AAOutputBuffer.BufferState state2 = output.DumpState();
+			deflateEncoder.GetBlock(input, output, 8072);
+			if (!UseCompressed(deflateEncoder.LastCompressionRatio))
+			{
+				input.RestoreState(state);
+				output.RestoreState(state2);
+				copyEncoder.GetBlock(input, output, isFinal: false);
+				FlushInputWindows();
+			}
+			break;
+		}
+		case DeflaterState.StartingSmallData:
+			deflateEncoder.GetBlockHeader(output);
+			processingState = DeflaterState.HandlingSmallData;
+			goto case DeflaterState.HandlingSmallData;
+		case DeflaterState.HandlingSmallData:
+			deflateEncoder.GetCompressedData(input, output);
+			break;
+		}
+		return output.BytesWritten;
+	}
+
+	public bool Finish(byte[] outputBuffer, out int bytesRead)
+	{
+		if (processingState == DeflaterState.NotStarted)
+		{
+			bytesRead = 0;
+			return true;
+		}
+		output.UpdateBuffer(outputBuffer);
+		if (processingState == DeflaterState.CompressThenCheck || processingState == DeflaterState.HandlingSmallData || processingState == DeflaterState.SlowDownForIncompressible1)
+		{
+			deflateEncoder.GetBlockFooter(output);
+		}
+		WriteFinal();
+		bytesRead = output.BytesWritten;
+		return true;
+	}
+
+	void IDisposable.Dispose()
+	{
+	}
+
+	protected void Dispose(bool disposing)
+	{
+	}
+
+	private bool UseCompressed(double ratio)
+	{
+		return ratio <= 1.0;
+	}
+
+	private void FlushInputWindows()
+	{
+		deflateEncoder.FlushInput();
+	}
+
+	private void WriteFinal()
+	{
+		copyEncoder.GetBlock(null, output, isFinal: true);
+	}
+}