add workflow
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Benjamin Palko
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docs/WORKFLOW.md
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docs/WORKFLOW.md
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# Workflow — reverse-engineering a server binary
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The repeatable process used for `Agent_Release_x64.exe`. Follow it for each
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binary in `decomp/INVENTORY.md`. Ground rules, layout and tooling are in
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`AGENTS.md`. What has been learned so far is in `docs/ARCHITECTURE.md`.
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Every finding is recorded as **observed**, **inference** or **unknown**, with an
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Evidence ID or decomp file reference. Static analysis never establishes runtime
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behaviour.
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---
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## 0. Prerequisites (once per machine)
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- Ghidra is at `/opt/ghidra`, and Java 21 and Node come from `mise.toml`.
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- REA MCP is registered project-locally in `opencode.json`.
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- Don't reinstall any of these; repair the configuration instead.
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- **Ghidra headless fails with `UnsupportedClassVersionError` (class file
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71.0):** its compiled-script cache was built by a newer JDK.
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- Move `~/.config/ghidra/ghidra_<ver>_DEV/osgi/compiled-bundles` aside.
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- Ghidra rebuilds the cache on the next run.
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## 1. Identify the binary (cheap, before any decompilation)
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```sh
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sha256sum binaries/<X>.exe
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objdump -p binaries/<X>.exe | grep -E 'DLL Name|Subsystem|MajorLinker|pdb'
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```
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In REA:
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1. Run `open_binary` with the original path under `binaries/`.
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2. Run `binary_overview`.
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3. Run `search_strings` (regex) for config paths, log text, protocol names and
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class names.
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Record the SHA-256, linker version, PDB path, imports and procedure count in
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`decomp/<X>/evidence.md`.
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## 2. Determine language and toolchain
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Check for these C++ markers:
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- RTTI descriptors (`strings -a | grep '^\.?AV'`)
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- `__CxxFrameHandler3`
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- an `MSVCP*.dll` import
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All 16 servers are MSVC 2010 C++ (see `docs/ARCHITECTURE.md`). Re-check each
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new binary and record the result.
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## 3. Discover third-party libraries and acquire their sources (**mandatory**)
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Any library you can match against upstream source saves you from
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decompiling it, and gives names, struct layouts and intent that the binary
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lacks. **Every time a library is found, search for its source online before
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continuing.**
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### 3a. Find candidates
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| Signal | How |
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|---|---|
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| Imported DLLs | `objdump -p` DLL names, cross-checked against `binaries/*.dll` |
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| DLL version resources | `strings -el <dll> \| grep -A1 -E '^(FileVersion\|ProductName\|CompanyName)$'` |
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| Embedded version text | `strings -a \| grep -iE '<lib>/[0-9]\|part of OpenSSL\|libcurl/'` |
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| Statically linked C++ libraries | RTTI class prefixes (`TiXml*`, `Proud::*`, `ATL::*`) |
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| Library-specific strings | assert/error messages (`Proud::CNetServerImpl::…`, TinyXML error table) |
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| PDB paths | e.g. `…\OpenLibrary\openssl-1.0.0d\…`, which names the exact version |
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### 3b. Pin the version
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Use, in this order of preference:
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1. An explicit version string (VERSIONINFO, `"OpenSSL 1.0.0d 8 Feb 2011"`).
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2. A version in the PDB path.
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3. **Differential evidence:** download several candidate releases and compare a
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distinctive artefact with the binary. Examples are error-string tables,
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exported symbol lists and header constants.
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- Example: the TinyXML error table contains `Memory allocation failed.`.
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That entry exists in 2.5.x and was removed in 2.6, which gives 2.5.1–2.5.3.
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4. If none of these work, choose the closest era-compatible release and mark it
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**closest, not exact**.
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### 3c. Search for the source
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Search in this order:
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1. Official release archives (project site or SourceForge; check `old/` and
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`archeology/` paths).
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2. Official git tags (`git ls-remote --tags <repo>`), or a GitHub tag archive
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if the release tarball no longer exists.
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3. Vendor package repositories. These often contain headers only.
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4. Clean-room equivalents (for example mingw-w64 headers for Microsoft APIs)
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or open reimplementations (for example Wine).
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5. `gh search repos <lib>` for forks or mirrors. Treat these as unverified and
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label them that way.
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Verify each download against an official checksum where one exists. Always
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record its SHA-256.
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### 3d. Check the licence and place the files
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| Licence | Location | Committed? |
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|---|---|---|
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| Open source (OpenSSL, curl/MIT, zlib, BSD, public domain) | `third-party/<lib>-<version>/` | Yes |
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| Proprietary or EULA-restricted (e.g. ProudNet) | `third-party/_local/<lib>-<version>/` | **No.** It is gitignored. Ask the user before fetching. |
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| No public source (XTrap, Apex, HASP runtime) | nothing downloaded | Record acquisition routes only |
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Other rules:
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- Keep upstream files unmodified. If you must change one (for example curl's
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version stamp), record exactly what changed.
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- Read the licence before committing anything. If redistribution is
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prohibited, it goes in `_local/` or isn't fetched.
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### 3e. Document it
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Add a row or section to `third-party/README.md` with:
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- the observed identity in the binary, with where it was seen;
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- the version and how it was pinned;
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- the source URL, tag or commit, and SHA-256;
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- match quality (exact / closest / headers only);
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- the licence;
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- any local edits.
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Also:
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- Mention the library in `docs/ARCHITECTURE.md` if it is statically linked.
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- Add it to the list in `AGENTS.md`.
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- If no source exists, add it to the "No public source" and "Acquisition
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routes" tables instead.
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### 3f. Use it
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- Label library functions in the decompiled output from known exports, class
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method tables, error strings and the matched headers.
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- Exclude labelled library code from application analysis.
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## 4. Decompile
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In REA, choose seeds from distinctive strings or imports and use
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`trace_feature` to find the functions that reference them. Then run
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`procedure_pseudo_code` / `batch_decompile` on those functions.
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For full coverage, run Ghidra headless with the repo scripts:
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```sh
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analyzeHeadless /tmp/opencode/ghproj X -import binaries/<X>.exe -overwrite \
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-scriptPath decomp/scripts -postScript ExportDecomp.java "$PWD/decomp/<X>/full" -deleteProject
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analyzeHeadless /tmp/opencode/ghproj X -import binaries/<X>.exe -overwrite \
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-scriptPath decomp/scripts -postScript VTableMap.java "$PWD/decomp/<X>/full/vtables.tsv" -deleteProject
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```
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This produces:
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- `full/functions/<addr>.c` and `full/index.tsv` from `ExportDecomp.java`;
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- `full/vtables.tsv` from `VTableMap.java`, which maps class vftable slots to
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functions.
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Generate `cpp/classes.hpp` from `vtables.tsv`, then check that it compiles:
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`g++ -fsyntax-only`.
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## 5. Record evidence
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In `decomp/<X>/`:
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1. Run `export_evidence_bundle` to write `evidence-bundle.json`.
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2. Extract the REA pseudocode to `<addr>.pseudo.c` and the overview to
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`binary_overview.json`.
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3. Write `evidence.md`: the findings table (conclusion → type → evidence), the
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proposed function names, and the open questions.
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4. Update the status and role of the binary in `decomp/INVENTORY.md`.
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## 6. Lift to readable C++
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`decomp/<X>/cpp/*.cpp` holds hand-lifted code for the analysed functions:
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- Cite the original address on each function.
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- Mark every name as inferred.
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- Record the original bugs you notice (leaks, races).
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## 7. Port to Linux
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`src/<name>/` builds the lifted code with Meson (see `src/README.md`). Keep a
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`platform.{hpp,cpp}` layer that maps each Win32 call to its nearest POSIX
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equivalent.
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The per-binary `README.md` must contain:
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- a substitution table: original address → Win32 API → Linux replacement →
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behaviour difference;
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- what is stubbed or not ported, and why.
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Build with `ninja -C build` and smoke-test it. A passing test proves only that
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the port works, not how the original behaves.
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## 8. Close
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Run `close_binary` when the investigation is complete. Before closing, export
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the Evidence bundle, because session annotations are temporary.
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---
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## Checklist per binary
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- [ ] SHA-256, imports, linker and PDB recorded
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- [ ] Language confirmed
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- [ ] **Every third-party library identified, its version pinned, its source
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searched for and downloaded where licensing allows, and it documented in
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`third-party/README.md`**
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- [ ] Key functions decompiled; `full/` export done
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- [ ] `evidence.md`, `INVENTORY.md`, `docs/ARCHITECTURE.md` updated
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- [ ] Lift and Linux port updated, if in scope
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- [ ] Evidence bundle exported; REA session closed
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