Version synced across the four locked points (pyproject, __version__, README
badge, README install pin) + CHANGELOG.
Corrections this release carries, both measured rather than reasoned:
- docs/LIMITATIONS.md said the script-tag change removed "the last"
quadratic-backtracking site on the output path. It did not. Corrected, with
the 334.7s gate measurement that falsifies it.
- README's coverage line claimed 126/126 classes; the matrix reports 128/128.
Stale since before v0.3.2. Test badge was 642, actual 666.
New residual recorded (LIMITATIONS, now 30 items, README synced): the sweep
flags on timing above a 1.5ms noise floor at N=8000, so an arm hiding under it
could still cost ~23s at the cap. What this supports is "no arm worse than ~23s",
not "no quadratic arm remains" -- and the blind spot is demonstrated, since a
generic-payload pass found only one of the two patterns.
666 tests green, coverage matrix 128/128 with 6/6 gaps holding, exit 0.
The input-path duty `8deca93` scoped. All 83 lexicon patterns measured arm by
arm; two are quadratic, same shape 0.3.2 fixed -- a run in front of a required
literal that may cross the pattern's own opening anchor. Exponent 1.98 over five
points, so quadratic, not exponential.
markdown:link-anchor-injection `[` 1.91s @8k ~8.3h at the cap
markdown:link-anchor-injection `[system](` 0.006s @8k ~89s at the cap
markdown:link-ref-comment `[//]: # (` 0.22s @8k ~1.0h at the cap
Not input-path-only: `scan_lexicon` runs on the output path, so `scan_output("["
* 100_000)` took 334.7s. 0.3.2's "last quadratic site on the output path" was
false when written -- its sweep drove `[` only through `scan_active_content`.
Fix is anchor exclusion, not bounding (bounding attacker-controlled content is a
one-line bypass). The excluded char is `(`, not the obvious `[`: excluding `[`
drops `[//]: # (see [x] then ignore this)`, which no other pattern catches. The
anchors contain `(` too, so it telescopes at zero measured recall cost.
N is per row deliberately. The URL arm ran 0.9s UNFIXED at N=100_000 -- under the
2.0s bound, so that row could not have failed. Measured at N=300_000 instead,
where crafted (8.10s) and legitimate (0.926s) separate 8.8x.
Version sync in all four places (pyproject, __version__, README badge, README
install pin) plus the changelog entry for cff0437.
Two claims that were about to ship in the release note did not survive being
measured against a v0.3.1 worktree, and are corrected in LIMITATIONS first:
- "Report-only, so the cost is a review, not a block" was wrong twice. HIGH under
a low-trust preset is fail_secure, not a review -- report-only means the text is
never mutated, not that a finding cannot block. And the new script-tag false
positive costs no consumer a disposition at all: any text containing a literal
`<script>` already produced active:raw-html at HIGH on 0.3.1, so the same prose
disposed fail_secure under PRESET_USER_UPLOAD before this change and after it.
The fail-open that was closed is narrower for the same reason -- it existed only
in scan_lexicon called on its own; through either composed gate, raw-html
already caught the unclosed tag. What changed is the label, not the outcome.
- "The realistic long value is still caught by egress:jwt-token" was true and
hid the part that matters. Measured at the 257-char boundary: a generic long
password still trips entropy:base64-blob at CRITICAL, disposition unchanged.
A JWT used as a DB password is the case that moves -- its remaining detections
top out below CRITICAL, so the any-tier block is lost and PRESET_TRUSTED_SOURCE
drops from fail_secure to quarantine_review. PRESET_USER_UPLOAD still
fail_secures. Recorded as a behaviour change in the changelog, not buried.
The first probe for that boundary used a 300-char run of "A" and found nothing on
either version: all-same-char values are suppressed as placeholders. The probe was
wrong, not the pattern.
662 passed, coverage matrix exit 0, LIMITATIONS still 29 items = README's 29.
The output gate claimed LLM10 self-safety on the grounds that its patterns have
no nested quantifiers. True, and irrelevant: nesting is not what makes these
blow up. A run in front of a REQUIRED literal, reachable from a short anchor, is
enough -- crafted input repeats the anchor and never supplies the literal, so
every start position rescans the tail. Quadratic, not exponential, and the
max_scan_chars cap does not help: it bounds the input, and quadratic work on a
bounded input is still hours.
Measured, not argued. `<a:` x 100_000 took 23.4s in AUTOLINK_RE alone; the
composed gate on that payload took 458.7s, extrapolating to ~5.7 hours at the
1_000_000-char input the gate itself accepts. Size-matched ordinary prose runs
0.31s, so the separation is 18x-660x -- unlike the blob in the neighbouring
test, which is the *faster* side of prose and never exercised backtracking.
Two fixes, chosen per pattern rather than uniformly:
- active_content + lexicon JSON (15 runs): exclude the character that opens the
pattern's own anchor (`[` for markdown, `<` for tags), so a run cannot reach
past the next start position and the per-start costs telescope. Verified to
cost no recall: long URLs, long alt text, and `<` inside a quoted attribute
all still match. Bounding instead would have been linear too but wrong here --
the content is attacker-controlled, so padding past a bound would be a
one-line bypass of the EchoLeak class this table exists to catch.
- connstr egress (4 runs): bound the password at MAX_CONNSTR_VALUE. The
exclusion fix is unavailable -- the anchor character is `/` and passwords
containing `/` are the common case (measured: they match today). The residual
miss is a credential over 256 chars; a token that long is still caught by
egress:jwt-token.
hybrid-xss:script-tag had neither option: its run is the script BODY, which may
legitimately contain `<`. It now matches the opening tag and drops the
`</script>` requirement. That also closes a fail-open -- `<script>alert(1)`
unclosed was silently missed -- at the cost of flagging prose that merely
mentions `<script>`, now documented.
Found by the composed-gate test staying red after every individual scanner was
already linear: the lexicon's six html-obfuscation patterns were the remaining
813x. A per-scanner test alone would have shipped that.
662 passed (was 642), and faster than before the fix.
v0.3.0 made the untrusted upload path unusable: measured on both doors, an
ordinary remote image fail_secure'd and an ordinary link/autolink/refdef
quarantined, so only documents without external references persisted.
Two independent defects compounded; neither fix works alone:
1. `markdown-image: HIGH` fired on any external image. The exfil primitive is a
URL that moves bytes outward, not an image. `is_ordinary_url` now grades on
shape - http(s)/protocol-relative, no query, no userinfo, no percent-escape,
no opaque host label or path segment -> LOW; anything data-carrying keeps the
carrier's severity. raw-html and data: URIs stay HIGH unconditionally.
Opacity reuses entropy's primitives; floors calibrated against real doc URLs
(worst legit token H=4.08, exfil segments 4.36-4.54) and frozen in
calibration.
2. The quarantine_default floor fired on ANY finding, a premise that broke when
every ordinary link became a finding. It now fires at MEDIUM+ - a no-op for
every detector that shipped before 0.3.0 (no LOW/INFO exists), which is what
makes this a patch rather than a minor.
The corpus blind spot that let this pass 522 green tests is closed: the FP
corpus carries realistic markdown and is asserted on the OUTPUT gate under
PRESET_USER_UPLOAD, with a counter-corpus of exfil-shaped URLs that must still
block. Beaconing and short opaque segments are conceded in LIMITATIONS and
asserted by the coverage matrix rather than papered over.
No new public API; no new preset (0.4.0 work); allow_reserved default unchanged.
Version-sync across pyproject, __init__, README badge/status/install pin and
CHANGELOG, and cut [Unreleased] to [0.3.0].
Why minor: 0772daf made allow_reserved default to True on okf.import_bundle,
so a consumer who upgrades without touching their code gets a LOOSENED gate --
a reserved index.md/log.md in a received bundle is now scanned and may become
mergeable, where v0.2.0 rejected it unconditionally. Under 0.x a >=0.2,<0.3
pin absorbs a 0.2.1 silently but stops at 0.3.0, which is the signal such a
change should send. Found by llm-ingestion-okf, our first real downstream
consumer, against main.
Development Status stays 3 - Alpha and the README keeps "the public API may
still change": this ships the hardened surface (Sessions A/A2/B) to consumers
who are still pinned at v0.2.0 and therefore have none of it. It is not the
v1.0 freeze -- that stays gated on the first real integration coming back
green, which is exactly what 0.3.0 makes possible.
Verified: 522 passed; coverage matrix exit 0; version string present in all
four files; no dangling 0.2.0 outside CHANGELOG history.
Add a single declarative manifest proving, in one place, every vulnerability
class the guard stops — and the documented gaps it does not. This is the
real-case validation gate ahead of any v1.0 freeze (v1.0 stays parked until
verified on real cases).
- src/llm_ingestion_guard/coverage.py: stdlib-only manifest (CORE_CASES) +
narrated runner. `python -m llm_ingestion_guard.coverage` prints
class -> OWASP -> expected -> observed -> verdict; exit 0 iff every caught
class is caught and every documented gap holds. 126 caught classes + 4 gaps.
Lexicon cases are generated from load_lexicon() via a payload dict, so a
pattern with no payload fails loudly at import (self-verifying).
- tests/test_coverage_matrix.py: asserts total recall, that every documented
gap still holds, and completeness (every lexicon id + every OWASP anchor has
a case). Adds the full 25-pattern LLM02 secret-egress set (fixtures assembled
from split tokens so no secret shape sits in source) and the container-layer
front-end classes (CSV formula-injection, zip-slip, zip-bomb, symlink).
- README + CHANGELOG: point to the runnable matrix.
+165 tests (357 -> 522). No core dependency added.
Session D: move every calibration constant (entropy floors 5.4/128, 5.1/64,
4.7/40 + shape floors; MAX_SCAN_CHARS; rot13-min; cognitive-load lengths
2000/2500; disposition ranks; active-content severities) into one documented
calibration.py, so a parallel Node/TS port can mirror exactly the same numbers.
Pure refactor, zero behavior change: calibration is a leaf module (imports only
report.Severity) that entropy/lexicon/disposition/active_content now source
their thresholds from. MAX_SCAN_CHARS is re-exported from lexicon so output.py
and existing callers are unaffected. The 347 pre-existing tests pass unmodified;
new test_calibration.py freezes the values and asserts each detector actually
reads its threshold from calibration (identity-checked, not a dead copy).
Output gate step 3 now runs scan_secret_egress over every decoded base64
blob's plaintext, not only scan_lexicon. A base64-wrapped credential that
formerly vanished (decode fed the lexicon, which has no secret patterns)
now surfaces as decoded:egress:* carrying the blob offset. Evidence stays
length-only, so the decoded finding never leaks the secret value.
Hex-wrapped secrets remain a documented honest-limit (entropy exposes
decoded plaintext for base64 only). README honest-limits + CLAUDE.md
Kontekst updated; 3 tests added (347 passed, was 344).
A received OKF bundle MAY legitimately carry index.md (directory listing, read
first under progressive disclosure) and log.md (update history) at any level
(spec §3.1/§6/§7). import_bundle previously hard-rejected those basenames in the
T4 path gate, so a conformant third-party bundle was over-blocked in full
(FAIL_SECURE) — and because the reject fired before scan_concept, index.md's
body (the highest-priority injection surface) was never scanned.
import_bundle now defaults allow_reserved=True: reserved basenames are scanned
as structural files (path-safety checks — traversal / absolute / backslash / .md
— still apply). The shadow-reject (an *upload* masquerading as index.md) is
preserved: the front-end passes allow_reserved=False so a materialized upload
landing on a reserved basename is still refused. That front-end opt-in was
required to keep the shadow-reject once the default flipped (not in the plan's
Filer set; traced from the code).
- okf.py: validate_concept_path/_validate_concept/import_bundle gain the
keyword; validate_concept_path default stays False (strict standalone).
- tests: +3 (legit index/log admit; injection in index.md body caught;
okf_version frontmatter admits). Per-concept-iteration test switched to a
traversal vector; mode-b showcase's index.md surface reframed from
reserved-name-reject to index.md-body-scan.
- README honest-limits + CLAUDE.md context note the mode-b/upload distinction.
Suite: 341 -> 344 passed. Core invariant intact (dependencies=[]).
Close the EchoLeak wiring hole (CVE-2025-32711 class): markdown images/
links, reference definitions, autolinks, raw active HTML and data: URIs
now surface as report-only findings (active:*, OWASP LLM05) in
scan_output step 6, so screen_output and okf.import_bundle dispose of
them instead of admitting them with findings=[].
- new active_content.py: canonical home of the shared pattern table +
scan_active_content; neutralize refactored to import it (mutating API
and behavior unchanged, all neutralize tests pass as-is)
- images/links flagged only for absolute/protocol-relative URLs:
relative in-bundle links are legitimate wiki/OKF mechanism (principle 5)
- evidence carries defanged URLs only (hxxps://evil[.]example)
- EchoLeak vectors planted in both showcases; detach proofs cover them
- README export list + checklist step 6, CLAUDE.md context line updated
Suite: 321 -> 341 passed. Core invariant intact (dependencies=[]).
Pre-release hardening from an independent adversarial review; each fixed
test-first (failing test -> fix -> green). 214 tests pass.
- entropy (M1): decode-and-rescan now runs BEFORE false-positive suppression,
so an SRI/media-prefixed injection blob is still decoded and lexicon-rescanned.
Suppression gates only the entropy finding, never the decode.
- output/disposition (M3): the invisible-carrier invariant now holds on the
persist gate. scan_output flags zero-width/BIDI presence and disposition
treats those + lexicon:unicode-tags-present as any-tier carriers, so a carrier
in model output fails secure even under a trusted policy.
- contract (M2): assert_credential_allowlist catches a bare <PROVIDER>_KEY
(e.g. STRIPE_KEY) that the old regex silently missed (fail-open). Deliberately
broad: also flags PARTITION_KEY/SORT_KEY as loud, allowlistable FPs -- fail-loud
beats fail-silent for an isolation control.
- disposition (m6): guard runs decide inside its guarded block -> total
fail-closed even on a malformed report.
- output (m4): egress placeholder suppression anchors word markers (example,
todo, ...) to a word boundary, closing a fail-open where a real secret merely
containing such a word was suppressed.
Docs: CHANGELOG Security subsection; README honest-limit for lexicon dedup (m5,
documented tradeoff, not fixed).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HyRCQMocjZ6SmSQ6JidJ2k
Module 11 (final) — the top-level wiring. The library never makes the model call
(no SDK imported by the core), so the public surface is the toolkit plus two
library-side bookends around the caller's tool-less transform (Form 1, chosen
with the operator over an export-only toolkit and a full orchestrator — the
bookends fit existing pipelines with least friction, encode the two halves the
library can stand for, and impose no control flow):
- prepare_input(text, source=INPUT) -> PreparedInput(fenced, nonce, report):
§6 steps 1-2, sanitize THEN fence (carrier can never smuggle a forged
delimiter). Merged report carries both steps' findings; renders no disposition.
- screen_output(text, policy, *, provenance, transform_failed) -> DispositionResult:
§6 steps 6-7, scan_output under guard() so a scanner error fails CLOSED
(FAIL_SECURE, never a silent persist). transform_failed routes the compound
forced-fallback rule.
- __all__ exports the full framework-agnostic surface: detectors, result types,
disposition machinery + presets, contract asserters, the grounding seam.
Docs: README refreshed from the stale "brief / pre-implementation" line to a v0.1
alpha status with a Form-1 quickstart, the §6 adopt-this checklist, and an honest
-limitations section (structural unsolvability at the text layer; semantic
poisoning invisible to lexicon+entropy; text-only, no multimodal). CHANGELOG
seeded; CLAUDE.md remote/status lines corrected (remote IS set, no longer
brief-stage).
10 wiring tests (public surface, prepare_input compose, screen_output fail-closed
+ compound). 189 green (showcase + corpora follow).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HyRCQMocjZ6SmSQ6JidJ2k
Module 10 of the build order — interface only in the stdlib core (PLAN §67/§94,
BRIEF §7/§10). lexicon and entropy see surface signals; they are structurally
blind to semantic poisoning — a factually false or subtly biased claim, in clean
prose, carrying no suspicious token. Catching that needs grounding against a
source of truth (embedding classifier, retrieval check, LLM judge) — a model
call, and models never live in this core.
So this module ships exactly two things and no detector logic:
- SourceGroundingCheck: the text -> Report protocol a [judge] implementation
must satisfy to plug in. runtime_checkable for a coarse callable-vs-not
isinstance gate; a conforming impl may be a plain function or a stateful
callable holding a retriever/client — the grounding source of truth is the
impl's concern, never a seam parameter. Its findings flow through disposition
like any other detector's, with zero grounding-specific plumbing.
- no_grounding_check (bound as DEFAULT_GROUNDING_CHECK): the pass-through
default returning an empty Report. The honest scope note made structural —
semantic poisoning is not solved at the text layer, and the core does not
pretend to.
Design choice, tested: the default returns NO finding (not an INFO "unchecked"
marker). An INFO finding would flip every artifact to found and trip the
quarantine_default floor in disposition, quarantining every upload for a check
that never ran. The seam stays silent; the honesty lives in the contract.
8 new tests (pass-through empties, silence on semantic poison, protocol
conformance incl. a stateful judge stub, and a composition test proving a
plugged-in check's HIGH finding fails secure through disposition unchanged);
169 green total.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HyRCQMocjZ6SmSQ6JidJ2k
Module 9 of the build order — the differentiator. Where the other modules
detect and report, these are pure functions that ENFORCE an invariant and
raise: the write-time analogue of runtime least-privilege. They harden the
call a pipeline makes around its quarantined transform; the library makes no
model call itself.
Three asserts, matching the reusable-contract checklist (BRIEF §6 steps 3-4):
- assert_tool_less(request): the model request carries no tool surface —
tools/functions/tool_choice/function_call/mcp_servers, populated. Covers
both Anthropic and OpenAI request shapes; empty/None is genuinely tool-less.
- assert_credential_allowlist(env, allowed): the process env holds no
credential beyond this stage's allowlist (subset = least-privilege; the
enrichment stage sees only the model key, never the publish credential).
- scoped_env(env, allowed): the isolation primitive — strips off-allowlist
credentials, keeps PATH etc.; the assert then passes by construction.
Generalized from claude-code-llm-wiki tools/wiki_ingest/enrich.py
assert_quarantine (a pipeline-specific gate) into framework-agnostic pieces.
Two deliberate safety choices inherited from the reference: credential
detection is name-based (env VALUES are never read — value-scanning is the
output module's job); and a raised ContractViolation names only the offending
KEY, never a value, so it is safe to route to an alert channel (minimal-alert,
BRIEF §6 step 8). CREDENTIAL_NAME_RE ported verbatim from the proven reference.
23 new tests; 161 green total.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HyRCQMocjZ6SmSQ6JidJ2k
Module 7 of the build order: the last gate before model output is persisted.
Composes scan_lexicon + scan_entropy over the emitted text, feeds each base64
blob entropy decoded back through the lexicon (decode-and-rescan → decoded:*
findings with blob offset), and adds the LLM02 secret/credential egress layer
(cloud/provider keys, PEM headers, DB conn-strings, JWT, labelled
password/secret/api-key assignments) with placeholder/varref FP-suppression.
Report-only (never mutates; neutralize is the separate opt-in mutator). Evidence
carries only a description + match length — never the secret value. Self-safe:
single input-size cap, linear egress patterns. PEM patterns use -{5} form so the
module itself never trips a secret scanner. 26 new tests; 108 green total.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HyRCQMocjZ6SmSQ6JidJ2k
Build-order step 6. Close the EchoLeak class (CVE-2025-32711): active content in
persisted model OUTPUT that a downstream renderer auto-fetches or makes clickable,
exfiltrating data zero-click. These carriers are neither injection strings nor
high-entropy, so lexicon + entropy miss them — a distinct control (OWASP LLM05,
Improper Output Handling).
Defang, don't delete. URLs in active-content position are rewritten to a
non-resolvable but auditable form (https://evil.com -> hxxps://evil[.]com;
data:/javascript: colon neutralized to [:]); raw active HTML is escaped so a
renderer shows inert literal text. Visible information survives review; only the
machine-actionable affordance dies. Dot-defang is idempotent (never [[.]]).
Six classes, each a Finding: markdown-image (HIGH, the zero-click primitive),
inline-link (MEDIUM), reference-link definition (MEDIUM, the documented
image-filter bypass), angle-bracket autolink (MEDIUM), raw active HTML (HIGH,
inherently-active tag OR event/URL attribute — benign <b>/<em> left untouched),
standalone data: URI (HIGH). Processing order prevents double-counting.
Opt-in and separate: calling neutralize() IS the opt-in to mutate; the report-only
gate stays pure (design principles 3 & 4). Byte-identical on clean output, mirror
of the sanitizer invariant. Scope conceded in the docstring: a targeted defanger,
not a full HTML sanitizer.
17 tests: byte-identity + FP guards (lone <>[], metadata:, benign HTML), image
defang + non-resolvability, secret-exfil URL, inline/reference/autolink, raw-html
escape + script neutralization, data: URI, no double-count, counts, source.
[skip-docs]: README positioning + honest-limitations remains the deliberate
build-order step-11 deliverable (steps 1-5 likewise left README frozen).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HyRCQMocjZ6SmSQ6JidJ2k
Build-order step 5. Wrap untrusted content in a quarantine fence a downstream
trusted prompt can rely on: everything between the delimiters is data, never
instructions.
Two load-bearing properties:
- Per-call cryptographic nonce (secrets.token_hex, 128-bit) in the delimiter, so
an attacker embedded in the payload cannot forge the matching closing marker to
break out — the nonce is unpredictable and fresh every call.
- Marker-strip FIRST: fabricated fence markers already in the payload are removed
(any/no nonce, case-insensitive, ReDoS-safe negated-class regex) and flagged as
fence:marker-injection (HIGH, LLM01) before wrapping — defense in depth against
a lucky guess of the static skeleton, and it surfaces the attempt.
Pure text -> (fenced_text, report, nonce); only mutation is the marker-strip.
Nonce exposed so the caller can reference the fence in the trusted prompt.
10 tests: wrap/preserve, per-call randomness, nonce length, breakout containment,
marker-strip (+ case-insensitive), prose-word FP guard, source, empty input.
[skip-docs]: README positioning + honest-limitations is a deliberate build-order
step-11 deliverable (steps 1-4 likewise left README frozen). README status line
("pre-implementation") is stale and flagged for the step-11 refresh.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01K8GmKRCdsPjWYAKWsNgeQS
Build order step 4 — the load-bearing port from the llm-security seed
(injection-patterns.mjs + string-utils.mjs), stdlib-only.
- injection_lexicon.json: 83 patterns (CRITICAL/HIGH/HYBRID/MEDIUM) as the
single source of truth (regex + id + severity + owasp + desc), compiled once
by a thin loader. Decoupled from the engine for a future TS port.
- scan_lexicon(text, source, max_scan_chars) -> Report: matches every pattern
against a deduped variant set (raw / normalized / homoglyph-folded / rot13),
plus unicode-tag presence signal and the cognitive-load trap.
- normalize_for_scan chain ported: unicode-tags -> bidi -> HTML-entities ->
unicode/hex/URL escapes -> whole-string base64 (reuses entropy.try_decode_base64)
-> collapse letter-spacing; plus fold_homoglyphs / rot13.
- Self-safety (OWASP LLM10): input-size cap (scan prefix + flag oversize) and
ReDoS-safe port — the two nested-.*? sub-agent patterns bounded to
(?:\S+\s+){0,N}?; verified true positives still fire.
- Non-Latin data (homoglyph map, BIDI block) built from explicit code points;
JSON non-ASCII kept as \uXXXX escapes.
24 tests; 55 green total.
[skip-docs]: README positioning + honest-limitations is a deliberate build-order
step-11 deliverable (steps 1-3 likewise left README frozen). README status line
("pre-implementation") is stale and flagged for the step-11 refresh.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01K8GmKRCdsPjWYAKWsNgeQS
Build order step 3. Pure text -> findings detector ported from the
llm-security entropy-scanner seed:
- Length-calibrated Shannon-entropy classification (CRITICAL 5.4/128,
HIGH 5.1/64, MEDIUM 4.7/40).
- Shape floor: base64-like (len>100) / hex (len>64) reach at least MEDIUM
even when entropy alone does not trigger — the only path that catches hex
(16-symbol alphabet caps H at 4.0 < 4.7).
- Decode-and-rescan (must-have): base64 blobs that decode to printable text
are exposed on EntropyResult.decoded for a later lexicon rescan.
- FP suppression scoped to the text-relevant subset (base64 media data-URI
prefixes + SRI sha*- prefix); source-code-specific seed rules omitted.
Exposes ported primitives shannon_entropy / is_base64_like / is_hex_blob /
try_decode_base64. 16 new tests; full suite 31 green. Stdlib-only.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01K8GmKRCdsPjWYAKWsNgeQS
