Files
apk-reverse/docs/tool-verification
dabao1955 cd1df50a2a Complete the xvmp IR virtualizer end to end and measure the de-virtualization chain on a real fixture
The public xvmp tree ships a compiler half that was never compiled (no TU
includes the virtualizer headers; on dev trees they do not build), a weak
empty vm_exec stub, silent skips for unsupported IR, and a companion article
describing an earlier prototype that is not in the tree. This change completes
and measures the chain:

- Completed toolchain, merged into all four omp branches of that tree: gated
  new-PM pass wiring (-mllvm -irobf-irvm, section .irvm), FORMAT v3 bytecode
  (8-byte aligned slots, explicit load/store widths, stable CC_ cast kinds,
  per-index GEP byte scales, branch condition = operand 0), a strong-symbol
  vm_exec interpreter with a 23-check unit suite, and a VMP.h user header.
  Virtualized vs native output identical at -O0/-O1/-O2 on all four
  branches. One branch's ungated IRVM call in Obfuscation::runOnModule
  (rewrote .irvm functions in plain native builds) removed; IRVM is
  strictly flag-gated.

- Fixture measured end to end (fco+bcfobf+subobf+IRVM build): native-identical
  output; 17,961-step guest trace via VMP_TRACE; 24.6M-instruction host trace
  via a ptrace single-stepper; vm_handler_slice yields 95,184 segments / 18
  unique signatures; the fla outer state machine separates as a shuttle class,
  round-boundary segments split the trajectory, positional alignment names
  every handler segment (59/59 in a round; counts match the guest histograms
  exactly), zero unmapped with --opcode-map.

- Tooling hardening measured on the real fixture: opcode maps key by
  signature (first-block keys collide under a shared dispatch successor);
  apply_map keeps first-block keys as fallback, regression tests added.

- Environment boundary recorded: frida stalker does not work in these
  containers (measured past the syscall layer: primitives pass, agent loads,
  zero denied syscalls; the failure is inside the injected agent's hook
  machinery), an outer ptrace tracer conflicts with frida spawn, and the
  ptrace stepper is the working host capture path. Design lesson: a pure
  virtualized call can still be LICM-hoisted by the compiling optimizer.

Records: EXTENSION-sampling-crash.md SS5-SS6 (final-state rewrite),
known-limitations.md, ete-diff-tracing.md SS5, vm_handler_slice.py header,
capability matrix.
2026-10-16 14:45:03 +08:00
..

Tool verification record

This directory is the evidence record for the apk-reverse skill measured against real targets, kept separate from the skill itself so the Coverage statement in SKILL.md can be checked against the runs behind it, and so a later reader can tell which claims were observed, which were inferred, and which are still unverified.

It is not a set of target-specific notes kept for reuse, and it deliberately carries no target identity. The measurements are about the tools and the skill; they stay valid whichever APK produced them. Where a concrete figure was needed to make a point (a class count, a file size, a build time) the figure is kept and the target is named generically.

Targets measured: Flutter AOT applications, multi-dex, mid-size native library sets, no packer.

The APKs themselves are not in this repository (.gitignore excludes *.apk, and tools/).

Workbench paths are an operation record, not a pointer. A record may say a run happened at tools/_work/... so the command can be judged; .gitignore excludes tools/, so that path is not something a reader can open. Anything a reader is meant to follow is named under docs/tool-verification/ or inside the skill — that rule is why a reference document never cites a tools/ path as its evidence, even when the work happened there.

Strength labels

Every claim carries one of three labels, used the same way references/verification.md uses them:

  • observed — reproduced here, with the exact command and its output.
  • inferred — follows from observed facts, but the step itself was not executed.
  • unverified — assumed or reported by a tool and not independently confirmed.

Index

File Covers
TOOL-VERDICTS.md One verdict per tested script and external toolchain, with the independent cross-check behind it
FINDINGS.md Findings about the skill itself: defects, contradictions, boundary evidence
REPO-DECISIONS.md What changed in the repo as a result, and what deliberately did not

Extension-pass record

The extension pass (the six coverage gaps named in the external review: module ecosystem, extraction shells and VMP, emulation/RPC, native DBI, kernel-level environment, protocol layers) keeps its evidence here, one file per topic, in the same three labels:

File Covers
EXTENSION-device-run.md The on-device run against a hardened Flutter sample: the two control runs, the frida refusals, the twice-corrected pid-drift attribution, the failed-dump artefacts checked with dex_dump_validate.py, and a shared-device hazard measured with Stalker
EXTENSION-unpacking.md Extraction-shell diagnosis by trivial-body ratio, dex_dump_validate.py against a fixture derived from the sample's own shell dex, and the tool's own defect found during the run
EXTENSION-rootdump.md The root-side /proc/<pid>/maps + mem route that does not use frida: 17 real dex images recovered, the shell skeleton they are not, four device-shell traps, and the negative result on anonymous/ART-heap scanning
EXTENSION-lsposed.md Module route: the gradle-free build chain with timings, three build traps, LSPosed config-DB anatomy, the module that could never have worked, and the root-hiding configuration the device actually has
EXTENSION-emulation-rpc.md ASC/ddc measured on a hardened APK, Frida-RPC exercised end to end on a live device, and the unidbg build repair
EXTENSION-native-dbi.md Stalker: the zero-event boundary, the crash from following a hot libc export, and an offline protobuf round-trip that caught a defect in its own decoder
EXTENSION-kernel-ondevice.md The MT Manager APK MCP probe, the module-environment facts it could verify, and the kernel routes that this device's 4.14 kernel puts out of reach

Benchmark-pass record

The benchmark pass put public targets under the documented routes — tests/benchmark.md is the matrix, and these files are the evidence behind its rows. Same three labels. Several of these rows came back negative, and four of them overturned a conclusion this repository had already recorded; those are called out in the matrix rather than buried here.

File Covers
EXTENSION-benchmark-l1-l3.md The first two matrix rows: the L1 equal-length patch -> repack -> re-sign chain with its on-screen behaviour change and its zero-change control, and the L3 time-to-death baseline, the two spawn/patch/detach orderings that cannot work, and the terminate path that patching the obvious death site does not stop
EXTENSION-extraction-shell-bench.md dex_dump_validate.py against an 11-variant skeleton set: the trivial-body ratio as a bimodal result rather than a threshold, the three script defects the variants exposed, and the ranking that pointed at a modified image until independent review caught it
EXTENSION-stalker-exclude.md Stalker exclusion measured across three arms: the no-follow baseline, the follow that kills the process, and the follow with 20 modules excluded that survives but still delivers zero events
EXTENSION-java2c.md Java2C against JNI sinking: native-declaration density roughly 2000x apart, why a Java_* symbol search fails silently, and the Dex-to-C build chain no toolchain on this host could complete
EXTENSION-vmp-diff.md The known-plaintext differential: a 218-of-224-opcode coverage fixture, a closed-loop check that recovered 218/218 mappings with zero fabrications, and the one link that cannot be automated
EXTENSION-kernel-weapons.md The generated KernelSU/APatch scaffold and its three kernel-side templates, all shipped unbuilt, plus the structural correction that a userspace module cannot change a syscall return value
EXTENSION-split-apk.md Two real split sets through both branches: unified re-signing, the merge that is refused by design, the merge that succeeds, and the signer chain this host actually needs
EXTENSION-reconstruction.md The reconstruction pass: the doctor capability closure (a JDK-only PATH used to report "can re-sign", now BLOCKED with a next action), the zip rebuild that stops dropping per-entry metadata (zipalign -c -v 4 fails the old output and passes the new), and check_commands.py catching a documented flag that does not exist
EXTENSION-test-harness.md The executable half of the evidence: what tests/ asserts and what it measured, the dex_patch_bytes regression reproduced byte-for-byte, the 153 skips and 26 xfails that form the exit-code work order, the device-bound exclusion forced by an incident where the suite drove a real phone, and CI written but never run
EXTENSION-rasc.md The Rust ASC measured against the Python one: identical class-definition sets on two archives, the speedup per scenario, the build (no prebuilt artifact exists, and a 32-bit MinGW cannot link it), and the enum shape whose method bodies it drops with no warning
EXTENSION-protobuf-raw.md A schema-free decoder cross-checked against the official runtime and a real DataStore container, with the packed-boundary and proto3-zero ambiguities reproduced on real bytes

Absorption-pass record

A later pass absorbed mechanics from external skill repositories (reverse-skill, awesome-game-security, android-reverse-engineering-claude-skill, MobileRE-Skill), keeping each project's own discipline: only the phase, the checklist and the command pattern cross over, with the source URL and the access date recorded, and nothing vendored as a runtime dependency. These files live here rather than in the skill because two of them corrected a claim the repository had already written down.

File Covers
EXTENSION-desensitization.md The leak scanner's rules and exemptions, its four RESULT= states and exit codes, the escaping false positives, and the pass that found its own evidence file leaking 26 strong hits — the fixture's literal match values, quoted to prove the rules fire
EXTENSION-dart-aot-formats.md Two string-table claims tested against a real dual-ABI Flutter app: the arm64 packed scheme confirmed against literal tag bytes, and the assumed armv7 len*2/UTF-16 form refuted — the 32-bit record is [header u32][byte-count u32le][UTF-8], and the extractor's zero is a format mismatch rather than an empty table
EXTENSION-detection-pipeline.md Naming the check that fires: three arms on a public MASTG target (control alive, probe arm dead in ≈300 ms via strstr("frida"), with the TracerPid=0 versus 4-frida-mappings asymmetry), svc_scan.py's two decoders agreeing on an identical 214-site set, the layered Java-to-svc descent, and the ptrace-free dump boundary on targets whose dex is deflated inside the APK
EXTENSION-dexsql.md The SQL query layer adopted as a third indexer beside rasc/droidasc/ddc: identical class-definition sets on four archives (zero differences either way), the string xref agreement and the = versus LIKE match-semantics trap, decode against ddc disasm line for line, and the persistent cache measured as not a speed switch

Hardware-layer pass record

The hardware pass (hardware watchpoints, ETE differential tracing, kernel-side event injection) follows the same shape: what runs on a host is measured, and everything that needs a device or a kernel toolchain is an explicitly-labelled template whose gate says where it closes.

File Covers
EXTENSION-hw-watchpoints.md The ptrace hardware-watchpoint route: encoders accepted and refused exactly as the alignment rules demand, and the emitted on-device helper compiled clean as a static aarch64 ELF — while no watchpoint was armed on any device, and the ledger that says the ptrace route leaves TracerPid visible
EXTENSION-ete-diff.md The differential half measured on synthetic flattened-dispatcher fixtures (first divergence, unique-per-side sets), the gate/capture plumbing measured to the no-device boundary, and what was deliberately not done: no perf-with-CORESIGHT build, no cs_etm stream, no overhead claim
EXTENSION-kernel-instrument.md The kernel-side scaffold's generate/verify round trip, the spec-refusal rules shared with hw_watch.py, the capability map whose no cells do the gatekeeping, and the three-time-fenced experimental register-rewrite action
EXTENSION-sampling-crash.md The second hardware pass: trace_addr2sym.py verified against a real cross-compiled .so (readelf-cross-checked), the interpreter-trace slicer measured on the calibrated xvmp shape (including the 4x-margin bug it found in itself), and the flattening-recipe corrections read from the two public obfuscator implementations the user supplied
EXTENSION-absorption-kx.md The absorption pass over four public write-ups: the native-VM-recovery procedure (every step inferred), pitfalls P43–P46, the slicer's nested-loop diagnostic (with the latent len(tuple) bug this pass's review caught), and what deliberately did not cross over

Adding a run

Record the tools, versions and exact commands, and label each claim. Keep target-specific facts out: what belongs here is what a future reader can apply to a different APK — a defect, a measured cost, a method that did or did not work, and the cross-check that settled it.