f0bffd1b9340a97be794eaf23d51a012a1008116
2 Commits
| Author | SHA1 | Message | Date | |
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 joakimp
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836e35b320 |
redact: name the tiers where they are used, and stop the docstring lying about tier 3
Review caught that the tier vocabulary was used in the report, the commit message and the docs without being defined anywhere the reader would land, and inspecting that turned up two real defects rather than just a wording gap. 1. STALE DOCSTRING. The module still described tier 3 as if it redacts, which stopped being true when the 403-hit measurement demoted it to report-only. It also credited tier 3 with resolving the 40-hex-PAT-vs-commit-sha collision — false by default, since a reporting rule resolves nothing. Corrected, with the consequence stated plainly: in the default configuration a sha-shaped PAT is caught if and only if it belongs to THIS machine, because only a known value (tier 1) or a naming key (tier 3, reporting) can separate it from a commit sha. That is an accepted gap; the alternative is redacting every sha in the palace. 2. THE VOCABULARY NEVER REACHED THE OUTPUT. The tool prints rule names (github-pat, env-value, url-credentials) and nothing printed a tier, so the docs' tier language was unconnected to what an operator actually sees. Added RULE_TIERS as the authoritative rule -> tier mapping, tier_of(), and Finding.tier; the feeder now prints "T2:github-pat=6" so what matched and how much to trust it are both visible on one line. A self-test asserts every rule that can appear in a Finding maps to a tier, so adding a rule without classifying it fails the tests instead of printing "T?". Tiers, for the record, are three kinds of EVIDENCE (not three severities): T1 known value from this process's env — near-certain, zero FP by construction; T2 known vendor shape — strong, the prefix is meaningful; T3 key name says secret — candidate only, measured FP-heavy, reported. T0 is reserved for suspicions(), which is a measured NON-detection. Docs gain worked one-line examples per tier and a "which tier fired?" section showing real output. 46 self-test cases pass. |
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joakimp
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3d47937d06 |
feed: scrub secrets before staging a transcript, name-anchored not entropy-anchored
A palace is mined from transcripts, and transcripts contain whatever the terminal
printed. Measured on this fleet: one leaked bearer token had reached 3 drawers,
13 feeder inbox files across all three devices, and 10 local files spanning 10
days — from an agent inspecting an env var while debugging. That frequency is the
premise: this is a pipeline problem, not a discipline problem.
WHERE. bin/mempalace_redact.py, called from mempalace-pi-session at the point the
staged transcript is written. That single hook covers both transports, because
local mode mines the staged file and remote mode rsyncs that same file
byte-for-byte. Scrubbing operates on the parsed objects rather than the
serialized text, so string values are rewritten while keys, ids and structure are
untouched — scanning raw JSONL instead invents keys like "tapiKey" out of the \t
escape preceding a field name (observed, not theorised).
WHY NOT ENTROPY. The obvious "redact long random-looking strings" is actively
destructive here: drawer ids, chunk ids, event ids, replica ids, HLCs and commit
SHAs are all high-entropy, are the majority of random-looking text in a palace,
and redacting them is silent and permanent. Detection is anchored on meaning
instead: tier 1 literal values from this process's env whose NAME says secret
(zero false positives by construction, and the only tier that can tell a 40-hex
Gitea PAT from a git commit sha); tier 2 vendor-prefixed shapes (ghp_, glpat-,
xox*-, sk-, AKIA, AIza, hf_, JWT, PEM blocks, URL credentials, Authorization
headers); tier 3 name=value assignments.
THE MEASUREMENT THAT CHANGED THE DESIGN. Tier 3 was going to redact. Against
52 MB of real fleet transcripts it produced 403 hits, and inspection with values
masked showed most were ${VAR} interpolation in compose files, TypeScript
identifiers, a TYPE ANNOTATION (credentials: Credentials), an IPA attribute
holding a date (krbPasswordExpiration), AAAK diary shorthand, and terminal output
following a "Password:" prompt. Redacting those corrupts code and docs held as
memory to catch what tier 1 already catches by value. After adding guards for
interpolation, code context, non-secret key suffixes and all-digit values, the
enforced count fell 403 -> 29 on the same corpus. So tier 3 REPORTS and does not
rewrite unless MEMPALACE_REDACT_STRICT=1.
HONESTY ABOUT MISSES. Known false negatives are documented rather than papered
over: novel formats in bare prose, another machine's secrets, base64-of-a-secret,
line-split secrets. Every run prints a count including "0 redaction(s)", because
silence is indistinguishable from a scrubber that never ran, and suspicions()
reports high-entropy strings it did NOT redact as (length, fingerprint) so the
miss rate is measurable. Findings never carry the value — rule, label, length and
sha256[:8], enough to recognise a recurrence, not enough to recover the secret.
FAIL CLOSED: no scrubber, no staging (exit 3), overridable with
MEMPALACE_FEED_ALLOW_UNSCRUBBED=1 for a machine older than this file.
Tested: 42-case corpus in --self-test, including every palace id shape as a
must-not-redact case, idempotency, and a compound case the corpus caught where a
vendor placeholder was then re-matched by the URL rule (nested placeholder — the
secret was hidden either way, so only an exact-output assertion catches it).
End-to-end on 45 real sessions: 29 enforced, fail-closed verified at rc=3,
override verified loud. Server-side layer specified in docs/secret-hygiene.md §5
but NOT implemented — it is tier 2 only there, since the hub cannot see a
client's environment.
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