Commit Graph
4 Commits
Author SHA1 Message Date
inliver233 a552157f1b Close the byte-patching gap, add the server-config path, fix two script crashes
Worked end-to-end on a real unobfuscated commercial app (single-dex, no packer,
server-driven launch screen) and folded back everything that cost time. Net +17
files, no new dependencies, no sample-specific identifiers.

New references
  byte-level-patching.md
    The technique that was missing entirely. Equal-length in-place edits beat
    method rebuilding (measured on a real sample: method rewrite grew debug_info
    924 B -> 22.8 KB and the dex 4.32 MB -> 7.73 MB), but four failure modes are
    silent: same-length is not enough, branch polarity, verifier legality, and
    stale dex header fields. Covers locating an instruction's exact offset (why
    listings and byte-pattern guesses both fail), the instruction width table and
    the two traps that desynchronise a decode, neutralise-a-branch vs redirect-it,
    and the header's signature-then-checksum order.
  server-config-and-updates.md
    The most common shape of "ad" in a modern app, and the one usually
    mis-diagnosed: the server supplies UI the client renders. The two-layer fetch
    (local fallback then remote override) that proves it, finding the config DTOs
    through the field names data classes keep, why you patch the decision and not
    the data, deciding the scope of "remove", and remote re-enable / cached config
    durability.

New scripts
  dexutil.py             dependency-free dex reader: structural walk, exact
                         instruction decode, dex header recompute/verify in the
                         correct order, branch-target and operand helpers
  dex_find_insn.py       locate an instruction by decoded semantics, print its exact
                         byte offset with context and BOTH sides of any branch
  dex_patch_bytes.py     equal-length byte patches from a JSON spec: semantic match,
                         polarity pin via expect_next, equal-length enforcement,
                         verifier check, header recompute, re-decode to prove it landed
  dex_check_verifier.py  does any conditional branch target a move-result (bypassing
                         its producer)? Compares builds and separates pre-existing
                         findings from regressions the patch introduced
  coldstart.py           cold-launch capture: timed screenshot burst + logcat signals
                         + installed-build facts + launch timing, and a warning when
                         the foreground activity is not the app
  check_repo.py          maintenance check: every script parses and answers --help,
                         every referenced path resolves, every file is documented

Fixes found while running the above
  repack.py       wrote archives with a plain zipfile writer, which cannot satisfy
                  the Android R+ install gate: resources.arsc must be STORED *and*
                  4-byte aligned, and a zip extra record cannot express a 1-3 byte
                  pad (a stored filler entry is inserted instead). Also fixes the
                  central-directory pointer and adds an alignment gate to the output.
  usb_net_proxy.py, dex_strpatch.py
                  crashed on --help with a traceback instead of printing usage.

Updated
  toolchain.md            ddc added (single-binary dex->Java with query subcommands,
                          with measured timings and its real limits); "not on PATH is
                          not not-installed" with the search commands; which signer
                          to use and why jarsigner breaks alignment
  repack-and-sign.md      alignment requirement and its arithmetic; dex header
                          recompute; jarsigner hazard; vendor install interception
                          ([N] with no symbolic constant -> root pm install); the
                          installer can keep owning the screen after an install
  recon.md                resolve package identity from a tool, not from hand-read
                          AXML strings (a wrong package sends all later device queries
                          nowhere); snapshot the config surface during recon
  long-task-discipline.md captures you never looked at are not evidence (incl. the
                          consistent-but-wrong-window variant); long-context decay and
                          the record shape that survives it
  dynamic-frida.md        when live attach cannot work at all: static instrumentation,
                          static read, and self-recorded evidence, with the control
                          build caveat each one carries
  ad-removal.md           server-driven config is usually the EASIEST case, not the
                          hardest; a three-way zero result is a positive finding;
                          scope note on local brand splash vs promotional content
  pitfalls.md             P37 stale dex header checksum, P38 [-124] alignment,
                          P39 bare-numeric install failure, P40 wrong-window evidence,
                          P41 inverted branch polarity, P42 decode desynchronisation
  SKILL.md, README.md     symptom index, reference/script indexes and requirements
                          updated for all of the above
2026-09-20 02:05:41 +08:00
inliver233 e10fb2d308 Add observation-window hygiene and non-Java update gates
references/long-task-discipline.md
  New section: "Keep the observation window clean". Every conclusion rests on "the
  build I am looking at is the build I made", and that assumption fails silently:
  something else installs/reverts/clears the target mid-capture, the process was never
  actually restarted, or the installed artifact is not the one on disk. Guards, cheapest
  first: pin identity by hash (not filename, and immediately before the window, not
  hours earlier); declare a capture window and run no install/uninstall/clear inside it;
  timestamp it; prefer one continuous capture over several short ones. When a window
  turns out to be contaminated, discard and re-capture rather than salvage - a re-run
  costs minutes, a wrong conclusion costs the rest of the task and gets re-derived from
  the same bad evidence.

references/updates-and-forced-upgrade.md
  New Step 6: "when the check is not where you expect", covering three shapes that break
  the flip-the-comparison plan.
  - The check is native: a declared update entry point with zero Java callers means the
    invocation lives in a .so. Ordered remedies, starting with the one that needs no
    native work at all - attack the response, or feed the check a version it likes. "No
    Java caller" is not "unpatchable".
  - The dialog hands off to a browser or WebView: there is no installer call to find,
    and logcat truncates the URL to `dat=https://host/...`, so a grep gives you a host
    and no path. Approach table for recovering the real URL, with hooking intent
    construction as the reliable one.
  - Server-issued gate with a local fallback: read the failure branch first. If failure
    defaults to "no update", failing the request is the whole fix and also gives you an
    offline verification signal; if it defaults to "must update", it makes things worse.
2026-09-20 00:53:25 +08:00
inliver233 0ea42265b7 Add deliverable-form discipline, execution identity, and four reusable scripts
Generalized from a long hardened-target engagement. Additions target the failure
modes that cost the most time and are not yet covered; nothing here is sample-specific.

New discipline
- SKILL.md: a third override rule -- deliver in the environment the request requires.
  A root-only or live-instrumentation result can look like success while failing the
  actual requirement (unrooted, installable, self-contained). Also adds two classify
  questions: what form the deliverable must take, and which architecture/library is
  actually executing.
- long-task-discipline.md: "the most expensive drift" -- a constraint table (privilege,
  modification form, ABI, network, persistence, distribution), the checkpoint question,
  and how to report a privileged workaround as a fallback rather than a deliverable.
  Plus "bound every wait": timeouts on every command, budgets calibrated from
  measurement so slow and hung are distinguishable, and sampling an observable you can
  inspect instead of sleeping blind.
- environment.md: look at the screen instead of driving blind; which of the two screen
  evidence kinds is trustworthy (an empty accessibility tree is common for
  runtime-rendered UI, where the image is primary rather than a fallback); emulator
  console control and adb recovery; preflight before every experiment block.
- native-and-so.md: what the device claims vs what the package manager chose vs what is
  actually mapped; translation layers and their consequences for hooks and native
  checks; fat-APK ABI selection.
- runtime-data.md: when the app rewrites your edit (server refresh vs local
  regeneration), why chmod/chown cannot work because the app deletes and recreates the
  file, and the immutable-attribute fix; decoding a value that only looks encrypted.
- framework-runtimes.md: string encoding traps (a UTF-8 scan of a UTF-16 snapshot
  returns nothing and reads as "the strings were stripped"), and non-ASCII obfuscated
  identifiers -- resolve by shape, not by name.
- pitfalls.md: P23 the fix lives in a file the app rewrites; P24 the artifact changed
  but the wrong one is executing; P25 "search found nothing" treated as "not there".

New scripts (parameterized, path-agnostic, all with explicit timeouts)
- preflight.py  environment check: device, root, ABI/translation, clock skew, leftover
                proxy/forwards, dead device server, chosen ABI, free space
- lib_map.py    what is actually mapped into a live process: path, base, architecture
                from the ELF header, and whether it came from the APK or was
                materialized at runtime
- blob_decode.py search (don't guess) the framing of a stored value, then re-encode the
                edited payload with the same parameters
- snap.py       bounded burst screenshots + control-tree capture, with a stall detector
                and an explicit verdict on whether the tree is usable

All four were exercised against a live device while writing: preflight correctly
flags multi-device ambiguity and detected the ARM translation layer; lib_map read real
ELF headers and identified the translation shim; blob_decode round-tripped a
rotation+deflate+base64 blob at realistic size in ~0.2s; snap detected a stalled screen
across three hashes.
2026-09-19 22:08:01 +08:00
skill-maintainer 55432780fc Expand into packer/native/framework/long-task coverage; harden verification discipline
New references (loaded on demand, one topic each):
- packers.md: reading the shell's rejection signal, distinguishing self-inflicted
  failures from genuine refusals, mapping the validation boundary via single-variable
  tests, component-type rules (providers vs activities), picking a native host
- framework-runtimes.md: identifying Flutter/RN/Unity/Cordova, the wrong-layer trap,
  how to tell which layer draws a given UI before committing to a patch direction
- native-and-so.md: host-library selection criteria, DT_NEEDED does-not-call-JNI_OnLoad,
  relocation vs page-permission constraints and relocation-free bootstrapping,
  replacing Java methods from native code with trampolines and fail-safe guards
- long-task-discipline.md: live record structure, conclusion grading, drift checkpoints,
  handover contents, and the opposite failure of over-documenting

Pitfalls: +P18 install reported success but the build was never installed,
+P19 internal signal substituted for the user-visible outcome,
+P20 not-captured treated as not-present, +P21 two changes then attributing the result,
+P22 waiting on something that needs a human to advance.

SKILL.md: index the new references; add a runtime check for layer ownership to Q3;
add long-task rule; strengthen the verify step; add three hard constraints
(user-visible definition of done, no route discarded on compound evidence,
prove the device changed before measuring).

No app names, package names, or sample-specific identifiers anywhere.
2026-09-19 21:51:51 +08:00