llm-security/tests/golden
Kjell Tore Guttormsen bbada84e9f refactor(llm-security): build the SIG ruleset from vendored commons (malware-signatures 0.1.0)
Fifth and last consumer swap of v8 Phase 5 step 4. The seven known-bad-identity
signatures stop living in knowledge/signatures.json and are built from the
vendored commons artifact signatures/malware-signatures.json instead.

Measured before the swap over all seven positions -- id, family, severity,
pattern, description, provenance, key order, and recompilation identity under
the engine's unconditional `i` flag: zero divergences over 56 checks, in order.
The commons copy was extracted from this repository's own file at b0de0ca and
had not drifted.

knowledge/signatures.json is REMOVED rather than left in place. Keeping it would
have left two files spelling one table with nothing gating the drift, and its
golden `file:` pin would have gone on passing while pinning bytes no scanner
reads -- a gate reporting success without running. The pin is replaced by a
walked-module anchor over SIGNATURE_RULES, which is strictly stronger: the pin
covered the bytes on disk, the walk covers what `new RegExp` made of them.
Golden diff was exactly that and nothing else: 7 ADDED, 1 REMOVED, 0 CHANGED
(102/7/5 -> 109/7/4), each added source verified equal to the recompiled commons
pattern.

compileRules() moves into the new lib module and is exported, so the built-in
ruleset and the operator's sig.custom_rules_path path keep one implementation
rather than two copies of the defaulting logic.

Coverage by construction, not by memory: the probe table in the scanner test is
asserted against the LOADED ruleset, so a rule commons adds cannot arrive
without an end-to-end probe. Mutation of the vendored JSON fires in three
directions -- under-match (xmrig alternative dropped) reddens two scanner tests
plus golden; over-match (webshell rule widened to a bare `shell`) reddens the
clean-fixture false-positive probe plus golden; reorder reddens the declared-
order test plus golden.

Loud failure is contract: an unresolvable commons writes one line to stderr
rather than silently disabling known-malware detection, and never throws.

Suite 2247 / 2241 pass / 6 skipped / 0 fail. suite-counts.json untouched.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0151x4FVg9Mn55C2LvHLpHKo
2026-08-13 21:28:14 +02:00
..
patterns.json refactor(llm-security): build the SIG ruleset from vendored commons (malware-signatures 0.1.0) 2026-08-13 21:28:14 +02:00
README.md fix(llm-security): golden gate - coverage block measured something else 2026-08-09 13:06:45 +02:00
reference-run.json fix(llm-security): golden gate - coverage block measured something else 2026-08-09 13:06:45 +02:00
suite-counts.json test(llm-security): v8 Phase 5 step 1 - golden baseline before any table swap 2026-08-09 12:57:51 +02:00

Golden baseline — v8 Phase 5

Reference artifacts recorded before any commons extraction, so that each table-by-table swap in Phase 5 can be proven behaviour-preserving (or rolled back). Generated and checked by one code path:

node scripts/golden-baseline.mjs            # check only, exits 1 on drift
node scripts/golden-baseline.mjs --write    # (re-)bless
node scripts/golden-baseline.mjs --write --suite   # also refresh suite counts (slow)

The gate is tests/lib/golden-baseline.test.mjs.

The artifacts

File What it pins Why that layer exists
patterns.json .source + .flags of every RegExp reachable from the walked modules' exports After a swap a pattern is new RegExp(jsonString, flags). The plan's named hazard — JSON backslash-doubling — is visible only on the compiled object.
↳ table records key/value digest of HOMOGLYPH_MAP, TYPOSQUAT_SUSPICIOUS_TOKENS, SEVERITY, the four OWASP maps Most of what Phase 4 moves is not a regex. A regex-only dump is blind to a broken homoglyph or OWASP-map swap, i.e. blind to the bulk of the payload.
↳ file records sha256 of the five source files in the moving set The completeness layer, complete by construction: it covers regexes inlined in function bodies (NAMED at string-utils.mjs:291, the BIDI/tag/PUA ranges at 357404) that no export walk can reach.
reference-run.json the 61 showcase payloads through the real hook entry points, plus a static reachability probe Byte identity over a corpus that trips a handful of patterns would prove almost nothing, so reachability is recorded and unreachable patterns are listed by name.
suite-counts.json per-file pass/fail, each file run alone A total is unattributable, and npm test runs files concurrently where three timing-sensitive files flake. Running each alone is the only reproducible recording.

Why there is no regex enumerator

The obvious design — parse the sources and enumerate every regex literal — was rejected. It needs a JS parser this zero-dependency repo does not have, and a lexical approximation is contaminated by comments and division (severity.mjs scores 4 "regexes" that way and exports none). The two-layer split — export walk for what the scanners actually use, file digest for everything else — answers the same question without a parser.

During a swap

A diff here means the swap changed observable behaviour. Roll the swap back. --write is for deliberately re-blessing a change you have already decided is correct, not for making the gate quiet.

Known coverage gaps — read before quoting a number

coverage is static reachability, NOT observed coverage. It probes the 61 payload strings against the 83 injection patterns in-process: "if you threw every payload string at every regex, how many would match?" It does not measure what the 61 hook invocations evaluated — the pre-bash-destructive payloads never reach injection-patterns at all, yet their strings are in the probe set and can mark a pattern reachable. 47/83 is therefore an upper bound on what the corpus could protect, not a measurement of what it did.

The block is named kind: "static-reachability" and carries that caveat in a note field; the gate asserts both, so the honest label cannot be dropped quietly.

Two gaps follow:

  • 36 unreachable patterns, listed by key under coverage.unreachablePatterns. A swap that breaks one of those is caught by the pattern dump only. Closing it means growing the conformance corpus (Phase 5 step 5).
  • The four OWASP maps have no behavioural coverage at all. They are scanner-side and no hook in this corpus reaches them. They were the reason the dump was widened to table records, and the digest is their only protection — do not read the reference run as backing them.

corpusContains says a payload contains a homoglyph or is altered by normalizeForScan. It does not say the run folded one.