rea/docs/managed-code-analysis.md

Managed-code analysis and planned extensions

REA inspects .NET PE/CLI artifacts without loading or executing their code. It can identify an assembly, inspect metadata and CIL, compare members across builds, and connect declared native calls to supplied native-analysis evidence. CIL is Common Intermediate Language, the instruction format used by managed assemblies.

The seven shipped tools are:

Task	MCP tool
Identify an artifact and its managed deployment form	inspect_managed_artifact
Inspect types, signatures, method bodies, calls, and field access	inspect_managed_members
List declared native calls and native implementation indicators	inspect_managed_native_boundaries
Compare members across builds and map build-local tokens	compare_managed_members
Check native call declarations against supplied export or function evidence	verify_managed_native_boundaries
Import decompiled code against verified static member identities	import_managed_reconstruction
Add managed findings to an application graph	project_managed_application_graph

Each has a matching CLI command: replace underscores with hyphens and prefix the name with rea, for example rea inspect-managed-artifact. Native-body bridge mapping remains planned; managed runtime execution is not part of the current tool set.

This guide describes the implementation and verification of ADR-0003. The canonical tool inventory is product-catalog.json.

Shipped scope

The canonical parser admits PE/CLI bytes and their metadata/CIL without loading an assembly. It reports observed implementation markers and unavailable facts; it does not unpack .NET single-file hosts, decode IL2CPP metadata, or infer a NativeAOT identity from an ordinary native PE. Inputs without admitted CLI metadata do not become managed assemblies through naming or routing guesses. Inspect separately obtained components explicitly and preserve their identities.

The broader deployment classification and native-body mapping below are design goals from ADR-0003, not claims that every row has an implemented parser. A valid marker can establish a candidate native boundary, not recovered native semantics or runtime behavior.

Analysis objective

REA's managed-code track is intended to answer five different questions without collapsing them:

1. What exact artifact and managed deployment form is this?
2. What do its admitted metadata and CIL bytes state?
3. What source-like or behavioral structure can be reconstructed or inferred?
4. Which findings survive an exact-build check or a cross-build structural comparison?
5. Which remaining questions require native analysis or runtime evidence that static inspection cannot supply?

The ordinary workflow ends at question four. Static analysis never loads or executes the target.

Planned deployment classification

The intended extended classifier proceeds from outermost authenticated bytes inward:

source path
  -> canonical path, size, SHA-256
  -> container inventory
  -> PE/native header and architecture
  -> CLI header and metadata root
  -> deployment/runtime markers
  -> per-component and per-method implementation availability
  -> managed-only, native-only, composed, degraded, or unsupported route

The planned result is a vector rather than one label. For example, a single-file modern .NET deployment can contain a native host, ordinary CIL assemblies, and ReadyToRun components. Each component receives its own digest, classification, coverage, and route while retaining the outer bundle commitment.

Case	Required positive observations	Claims that remain unavailable or inferred
.NET Framework	Valid CLI metadata plus bounded Framework-specific target/reference evidence	Exact installed CLR and runtime behavior
Modern .NET	Valid CLI metadata plus bounded target/reference/runtime-config evidence	Exact runtime selected on another host
Unity Mono	Valid managed assembly plus authenticated Unity context when supplied	Engine behavior or native integration not represented by metadata
ReadyToRun	Valid managed metadata plus authenticated ReadyToRun header/sections	Native implementation semantics until a selected deep provider analyzes them
C++/CLI	Valid CLI metadata plus mixed-mode PE/header evidence	Mapping managed declarations to native implementations without explicit bridge evidence
Single-file	Valid authenticated bundle inventory and component extents	Components that are compressed or encoded by an unsupported bundle version
Unity IL2CPP	Authenticated native image/metadata pairing and supported metadata version	Canonical CIL and source-equivalent C#
NativeAOT	Native image plus bounded NativeAOT evidence	Ordinary CLI metadata/CIL unless independently present
Obfuscated assembly	Same positive byte observations as its underlying deployment form	Meaning inferred only from names
Malformed/unsupported	Exact admitted regions and failure locations	Completeness, successfully skipped rows, or semantics beyond the admitted parser boundary

NativeAOT metadata recovery

NativeAOT removes the ordinary CIL method bodies, so a CIL decompiler cannot reconstruct those bodies as C# source. The executable remains a native target for Hopper or Ghidra, where decompilation produces pseudocode and analyst inference. This is a different route from ordinary managed member inspection.

NativeAOT is not limited to Windows .exe files. The native image can be PE, ELF, or Mach-O, and NativeAOT can also publish shared libraries (PE DLL, ELF .so, or Mach-O .dylib) with explicitly exported entry points. Identify the image from its bytes and loader metadata, not its filename extension. When the image is inside an application bundle, inventory or extract the bundle first and carry the component identity into native analysis. Matching PDB, ELF debug, or dSYM sidecars can add symbol evidence when the selected provider supports them; verify their identity and keep them separate from observations made from the executable itself. Microsoft's NativeAOT overview lists supported OS/architecture targets and deployment limitations, while its native library guide describes exported shared-library entry points.

The Ghidra NativeAOT analyzer is a useful optional companion for recovering ReadyToRun metadata. It rehydrates the DEHYDRATED_DATA section and annotates method tables, type relationships, vtable slots, frozen objects, and strings. It does not recover original C# method bodies. It is a separate Ghidra extension and interactive metadata browser; REA does not currently install or invoke it through its headless bridge. Its README describes ReadyToRun header discovery, including symbol-based and heuristic paths, so a missed header or unsupported binary should remain an explicit limitation rather than a failed claim about the binary's contents.

The upstream analyzer currently gates its own analysis to x86-64. NativeAOT's broader platform matrix does not establish REA coverage: PE/COFF, ELF, Mach-O, shared libraries, target architectures, and runtime metadata versions each need their own provider verification. REA's experimental Windows Ghidra boundary is limited to admitted native x86-64 PE applications, so it does not currently establish coverage for PE DLLs. Mobile NativeAOT targets should remain experimental until REA has a matching provider and package-level verification.

For REA's native analysis, preserve the same artifact path and digest used by inspect_managed_artifact, and report recovered type data as provider observations. Linking those types to native function addresses requires verified provider evidence; names or vtable similarity alone do not prove that a native function implements a specific managed method.

Evidence record shape

Every planned operation returns a provider result and Evidence with four commitment groups:

Artifact commitment

• canonical local path, byte length, and SHA-256;
• outer-container identity and digest when inspecting a component;
• component name/path, byte extent, and SHA-256;
• observed PE machine, CLI flags, and conflicts;
• classification vector, supporting observations, and unresolved dimensions.

Module commitment

• assembly simple name, version, culture, public-key/token state, flags, and hash algorithm;
• module name, generation, and MVID;
• target framework and runtime/version strings with their exact metadata locations;
• provider identity, analysis-affecting parameters, and their profile digest.

CLI #GUID heap values are committed as their exact 16-byte GUID text. REA does not impose RFC 4122 UUID version or variant bits on MVID, EncId, or EncBaseId because ECMA-335 metadata does not require those bit patterns.

Entity commitment

• table kind and build-local token;
• declaring scope and normalized CLI signature;
• row/heap/body locations expressed as typed file offsets, RVAs, or CIL offsets;
• exact raw bytes or bounded value digest;
• raw CIL digest plus separately reported method-header, locals-token, and exception-region observations where available;
• a deterministic decoded-instruction-tuple digest for completely decoded CIL, with the limitations below.

Shipped decoded-CIL fingerprint

inspect_managed_members exposes two method CIL hashes with different byte boundaries:

Field	Input	Excluded from the digest
il_sha256	The exact il_size raw CIL bytes after the tiny or fat method header	Method header, locals signature blob, alignment, and extra sections including exception clauses
normalized_il_sha256	UTF-8 JSON.stringify output for the instruction-order array of [opcode, operand_kind, operand] tuples	Instruction offsets except projected scalar branch targets, switch targets, resolved metadata/string identities, method header, locals, and exception regions

The normalized field is available only when the entire CIL stream decodes with status present. A malformed or absent body reports null. The tuple format is defined here.

Tuple operands use these exact projections:

• operand-free instructions: none and null;
• metadata and user-string operands: the build-local token as lowercase 0x-prefixed eight-digit hexadecimal;
• scalar branches: the target CIL byte offset as a decimal string;
• switch: the case count as a decimal string, without target offsets;
• signed integer and variable operands: decimal strings; floating-point operands: JavaScript's String representation of the decoded IEEE value.

Opcode names retain short/long forms and prefix opcodes. This makes the value a reproducible decoded-tuple fingerprint, not a canonical semantic CIL identity: it does not resolve tokens across MVIDs, does not commit full control flow or exception semantics, and does not replace the raw CIL digest. Cross-build comparison uses the value only as one unique-only structural tier and reports ambiguity when that evidence is insufficient. A future normalized-CIL commitment would need canonical token/literal identities, complete branch and switch targets, and explicit locals/exception semantics.

For example, a decoded nop; ret body serializes exactly as [["nop","none",null],["ret","none",null]] and has digest 5e5fad7741cb44bca3a4f045546b7449990da343f612f5f34c0ca30e9eee0636. This vector specifies the tuple order, null handling, absence of whitespace, UTF-8 encoding, and lowercase hexadecimal output.

Epistemic commitment

• authority: static bytes, reconstruction, structural inference, independent validation, native provider, or future runtime observation;
• state: observed, inferred, unknown, or unavailable;
• confidence independent of authority;
• coverage and admitted/dropped counts;
• exact supporting Evidence IDs and actionable limitations.

A semantic label such as score_submission_gate can annotate an entity, but it is never the entity's identity. The same applies to an obfuscated name, token, RVA, or decompiler-generated local name.

Planned static capabilities

The caller-visible grouping and exact tool names are decided with the contracts that implement them. The underlying capability slices are:

1. Triage and inventory: container/component classification, assembly and module identity, references, files, exported types, resources, attributes, and runtime markers.
2. Member inventory: file-backed types, methods, fields, properties, events, interfaces, nesting, generics, and normalized signatures.
3. Method inspection: headers, max stack, locals, CIL instructions, constants, metadata operands, exception regions, and implementation flags.
4. Relationships: declared overrides, interface implementations, member references, direct CIL callers/callees, field access, construction, and interop declarations. Dynamic dispatch remains qualified.
5. Structural search and comparison: signature/API/constant/flow anchors, exact and normalized hashes, competing candidates, and explicit exact/structural/missing/ambiguous states.
6. Managed/native composition: P/Invoke, unmanaged exports, COM/mixed-mode declarations, ReadyToRun/native bodies, single-file hosts, and authenticated IL2CPP pairs linked to selected Hopper/Ghidra evidence. The shipped verification workflow checks P/Invoke declarations against supplied native export or function Evidence; native-body, thunk, and token-to-address bridge mapping remain unavailable without explicit provider-supported evidence.
7. Application graph projection: managed assembly/module/type/method/field, P/Invoke, and native-implementation declarations enter the same Evidence-backed application graph vocabulary as JavaScript/Electron findings while preserving managed static-analysis authority.

Inventory lists preserve deterministic order and include every fact available from the admitted PE/CLI streams. Malformed ranges and unsupported metadata are reported as coverage issues instead of being silently omitted. Search exposes scanned, matched, returned, and dropped counts. An unresolved indirect call or a failed signature decode is not silently omitted from a completeness claim.

Obfuscation-resistant method slices

Names are one weak feature among many. A behavior slice records the smallest bounded set of observations needed to investigate a proposition:

• normalized declaring/member signatures and inheritance/interface shape;
• framework and application API references;
• exact strings, numeric constants, enum-like values, and serialization keys;
• branch, switch, exception, loop, call, and field-flow shape;
• construction and generic-instantiation sites;
• raw CIL and decoded-tuple commitments, plus separate header, locals, and exception observations;
• callers, callees, shared fields, and competing candidates; and
• limitations from reflection, dynamic dispatch, generated code, protection, native transitions, or incomplete coverage.

The workflow produces separate observation, inference, validation, and unknown tables. It may say that a method is a strong candidate for a role; it cannot turn that role into the method's durable identity.

Cross-version matching first prefers exact CIL/signature identity. When that does not match, it pairs an exact declared type, method name, and raw signature before trying structural body shape. The exact-signature key uses names only as part of that full tuple; names alone never select a pair. Duplicate tuples remain ambiguous rather than being paired by token order. Fields follow the same exact tiers. The raw signature is exact whether or not REA decoded it, so undecoded signatures pair by that tuple too, but they never enter structural rounds. An unmatched member is therefore reported as unknown, not added or removed, when its own signature was not decoded or when the other side has an unpaired member, one-sided or ambiguous, with the same declared type and name whose signature was not decoded.

For a matched method, an unavailable or partial body makes body-shape facets unknown while preserving observed signature differences. Structural identity compares normalized signatures, the limited decoded-CIL tuple fingerprint, constants, and bounded shape context. It reports all candidates at the winning score and remains ambiguous when the evidence does not distinguish them. The digest does not itself remap metadata tokens.

Tokens are always remapped through observed structure. A caller cannot carry 0x06001234 into a new MVID and assume it names the same method.

Managed/native boundary rules

Boundary	Managed observation	Native observation	Permitted link
P/Invoke	Module, entry point, charset/calling-convention flags, declaring method	Import/export/symbol/function evidence from the selected deep provider	Exact declared-name/module link or qualified resolution inference
COM	Interop attributes, GUIDs, imported interfaces, method signatures	Native registration/vtable evidence when independently available	Identifier/signature inference with explicit environment limitations
C++/CLI	Managed declaration and implementation flags	Native body/function evidence	Only a provider-supported bridge observation; never token-as-address
ReadyToRun	Component/header and per-method CIL/native availability	Native section/function evidence	Authenticated image mapping with format/profile version
Unmanaged export	Export metadata/attribute when present	PE export and native thunk/function	Exact export identity plus provider-qualified address
Single-file host	Bundle entry/component identity	Host and native component evidence	Outer bundle plus component digest/extent commitment
Unity IL2CPP	Supported metadata entity with authenticated pairing	Generated native function/type evidence	Versioned IL2CPP mapping only; no invented CIL
Runtime-resolved native	API/constant/data-flow candidate	Loaded-module/symbol observation from an independently collected runtime source	Static candidate remains inference until separately observed

Declared import inventory supports a bounded positive claim. Its absence does not exclude dynamic resolution, generated code, protected code, native helpers, or server-side behavior.

Tool and packaging boundary

The production parser is REA-owned TypeScript and ships with the existing Node application. Deterministic conformance uses source-owned byte-built PE/CLI fixtures and expected semantic facts. An optional real ILSpy lane runs only when its executable is explicitly supplied; the default lane does not establish independent pinned-oracle parity. Production inspection needs none of those tools.

• A pinned System.Reflection.Metadata differential oracle is planned; it is not part of the current verifier.
• ICSharpCode.Decompiler/ilspycmd can supply reconstruction inference. A BYO reconstruction import records the supplied version and remains non-canonical. When REA_ILSPY_CMD_PATH points to an absolute runnable ilspycmd, verify:managed runs a source-owned real ILSpy oracle and imports its C# output as reconstruction inference against exact static member Evidence.
• dnlib and Mono.Cecil are potential future differential oracles. Their mutation APIs are not exposed or included in the production parsing boundary.
• The package contains no .NET runtime, SDK, ILSpy installation, proprietary assembly, or compiled conformance fixture.
• Setup never installs or upgrades those tools. Doctor may inspect an explicit optional path without changing it.

Real-tool downloads used in development or CI require exact package coordinates and SHA-256 lock entries. They are cached outside the source tree and restored into isolated directories. Updating any coordinate requires review of license, runtime, supported host, output contract, and conformance results.

Target platform is not host support. The canonical parser must inspect Windows-produced PE/CLI bytes on REA's supported Linux and macOS hosts with the same result. Pinned Windows oracle jobs may provide additional conformance, but they do not claim that the REA application itself supports Windows. Native ReadyToRun, C++/CLI, NativeAOT, or IL2CPP coverage is additionally constrained by the selected Hopper/Ghidra host and format matrix.

Source-built conformance corpus

The current lane uses source-owned byte-built fixtures and malformed-input regressions, with optional operator-supplied applications and ILSpy verification. The table below describes the desired expanded corpus; it is not a report that all compiler-generated forms have been independently verified.

Fixture sources are intentionally small and behavior-focused. Build outputs are generated outside tracked fixture directories and must not remain after verification or packaging.

Corpus slice	Required properties
Identity	Assembly/module/version/culture/public key, references, attributes, resources, MVID
Signatures	Nested/generic types, arrays, pointers, by-ref, function pointers where supported, varargs
CIL	Short/long branches, switch, prefixes, constants, locals, calls, fields, boxing, tokens
Exceptions	Catch, finally, fault/filter where the compiler/toolchain supports them
Generated structure	Async and iterator state machines, lambdas, closures, properties, events
Interop	P/Invoke flags, module/name mapping, managed/unmanaged implementation metadata
Architecture	AnyCPU, preferred-32-bit where applicable, x86, x64
Obfuscation resistance	Unicode/meaningless/duplicate-looking names and structure-preserving renames
Cross-build comparison	At least two builds with changed MVID/token order/layout and known same/changed behaviors
Malformed/adversarial	Truncated/overflowing headers, streams, tables, heaps, signatures, bodies, and EH sections

Verification compares semantic facts, not decompiler text. It checks resource ceilings, deterministic ordering, complete cleanup, CLI/MCP parity, Evidence commitments, packed-package behavior, and target-free MCP startup. A parser and an oracle disagreeing on malformed input is investigated explicitly; one tool's acceptance does not automatically make the bytes valid.

Operator-local osu! benchmark

The optional osu! benchmark accepts only paths and expectations supplied by the operator. Run it with:

REA_MANAGED_APP_MANIFEST_PATH=/absolute/managed-app-manifest.json npm run verify:managed

verify:managed always runs a source-owned manifest-verifier self-test first. If REA_ILSPY_CMD_PATH is set to an absolute ilspycmd path, it also runs a source-owned ILSpy oracle: version discovery, class listing, bounded C# output for a pinned fixture type, and import through import_managed_reconstruction. The verifier prints only command/version, executable and output digests, Evidence IDs, method locks, and compact fixture identity; it does not print decompiled C# text. A failing ILSpy oracle fails the verifier because it is an explicit real-tool claim, but leaving REA_ILSPY_CMD_PATH unset keeps the oracle disabled.

When REA_MANAGED_APP_MANIFEST_PATH is set, the manifest's target path may be absolute or relative to the manifest file. A compact manifest contains:

{
  "label": "operator-local osu!stable semantic slice",
  "target": {
    "path": "./osu!.exe",
    "sha256": "<exact target digest>",
    "mvid": "<exact module MVID>",
    "assembly_name": "<expected simple name>",
    "runtime_family": "dotnet-framework",
    "managed_architecture": "x86"
  },
  "methods": [
    {
      "label": "operator-local semantic label",
      "token": "0x06000000",
      "signature_sha256": "<raw signature blob digest>",
      "il_size": 0,
      "il_sha256": "<raw CIL byte digest>",
      "normalized_il_sha256": "<digest>"
    }
  ],
  "application_graph": {
    "expected_node_kinds": [
      "artifact",
      "managed-assembly",
      "managed-module",
      "managed-type",
      "managed-method"
    ],
    "feature_traces": [
      {
        "label": "operator-local feature label",
        "method_token": "0x06000000",
        "seed": "<method name, API name, string, or digest to trace>",
        "match": "exact",
        "case_sensitive": true,
        "min_matched_seeds": 1
      }
    ]
  }
}

Before evaluating methods, the verifier fails closed on target SHA-256, MVID, assembly name, runtime-family, and managed-architecture mismatches whenever the manifest supplies those fields. It then pages each declared MethodDef token directly by row, so selected methods do not need to appear in the first member page of a large application. Optional il_sha256 locks the exact raw CIL bytes in addition to REA's decoded-instruction-tuple digest. That normalized field has the byte boundaries documented above and is not a complete semantic CIL identity.

The optional application_graph block reuses those exact-build method commitments. For each referenced MethodDef token, the verifier builds a bounded managed application-graph projection from the authenticated artifact and the single selected member page, then checks requested node kinds and feature-trace seed matches. This proves only that the selected static facts enter REA's graph and tracing vocabulary for that exact local build; it does not execute the application, inspect arbitrary unlisted methods, or infer runtime behavior.

Output contains assertion status and compact identities only: file name, target SHA-256, MVID, assembly name, runtime-family, managed architecture, method tokens, method names, signature digests, IL sizes, normalized IL digests, graph Evidence IDs, node-kind summaries, and trace seed hit counts. It does not print method bodies, reconstructed C#, application data, runtime telemetry, account/service details, full filesystem inventories, or the target's absolute path. The manifest and target remain outside git.

The benchmark may prove that REA reproduces selected facts for that exact local build. It cannot establish general support on its own; source-built conformance remains the admission requirement.

Runtime behavior boundary

Managed inspection does not execute assemblies or observe CLR internals. Questions about actual behavior remain unknown until supported runtime evidence is collected. A direct process capture can retain declared inputs, outputs, filesystem and protocol activity for a target run; it does not prove which managed methods executed or how the CLR resolved them.

Delivery sequence

The managed-code track advances as reviewable pull requests:

1. accepted evidence/provider boundary (this document and ADR);
2. read-only artifact triage and exact identity (shipped);
3. file-backed metadata, signatures, method bodies, raw CIL hashes, and the decoded-instruction-tuple fingerprint (shipped; complete normalized-CIL semantics remain planned);
4. obfuscation-resistant slices and cross-version comparison (shipped for static member observations);
5. decompiler reconstruction import (shipped as analyst inference; REA does not run ILSpy/dnSpy, and metadata/CIL remain canonical);
6. managed/native composition and truthful deployment degradation (declaration inventory and native export/function Evidence matching shipped; native-body bridge mapping remains planned);
7. source-built managed conformance and package/CLI verification (source-owned PE/CLI corpus shipped through npm run verify:managed; optional BYO ilspycmd real-tool oracle shipped through REA_ILSPY_CMD_PATH; dnSpy and pinned Windows checks remain planned); and
8. managed static Evidence projection into the application graph (shipped).

Each implementation PR updates generated product facts only for behavior it actually ships and states which real-tool checks were performed.

Method metadata during build comparison

Managed member comparisons report a metadata dimension when an observed MethodDef flags or implementation flags value differs, including accessibility or synchronization changes. This is separate from the CIL/signature matching tiers: identical instructions do not establish unchanged method metadata. The reported difference is static metadata evidence, not proof of runtime behavior.