24 transactions across 11 connections from a retail session: login,
hub, one pack open, two squad saves, a quick-sell, with before/after
state manifests. Raw .ofcap stays gitignored at 0600; the sanitized
corpus is committed as adapter fixtures.
TWO GAPS FOUND BY AUDITING THE OUTPUT, NOT BY TRUSTING THE SANITISER.
1. `POST /ut/auth` carries `macAddress` and `deviceId`. Session tokens
were being redacted correctly and these were not. A committed fixture
is a published fixture.
2. Then, with those fixed, the audit fired AGAIN on the file about to be
committed: `GET .../phishing/trusteddevice?deviceId=...` puts the id in
the QUERY STRING. Three input surfaces carry identifiers -- headers,
JSON bodies, and query strings -- and the sanitiser knew about two.
Both fixed in the tool rather than by editing the file, with a
regression test and a mutation for the query path.
AND A THIRD ARTEFACT MIX-UP, in the mutation harness itself. It reported
the query-redaction mutation as SURVIVED while a hand-run of the same
mutation killed it. Cause: the harness pointed at a stale scratchpad copy
of the test that pre-dated the query assertion, so it was faithfully
testing the mutated tool against a test that could not detect the
mutation. That is the same class as the build guard checking the wrong
binary and cargo reusing a binary compiled from mutated source -- the
third instance today of measuring the wrong artifact. The harness now
resolves ROOT from its own location and runs the COMMITTED test; the
stale copy is deleted.
Harness committed as scripts/mutate-utas-observe.py so this is repeatable
rather than a thing that happened once in a scratch directory. 6/6 killed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
UTAS needs a real request/response corpus before any Rust is written: it
is where protocol shape and FUT state start being coupled, so guessing is
worse here than it was for Blaze. The oracle truncates logged bodies at
~200 chars, and raising that cap would mean editing the behavioural
specification to make it easier to copy -- backwards. A proxy gets the
same evidence and leaves the oracle untouched.
THE DESIGN RULE: TEE, DO NOT REBUILD.
UTAS is plaintext HTTP/1.1 on ThreadingHTTPServer, so keep-alive,
pipelining and chunked transfer are all live. A proxy that parses a
request and re-emits it can corrupt the traffic it exists to observe --
and that corruption would present as a UTAS bug, pointing the
investigation in exactly the wrong direction. So bytes are copied
verbatim in both directions and a second copy goes to disk; transactions
are reconstructed later, offline, from that copy. A parser bug therefore
spoils the record and never the session.
Standalone, NOT in the container, so the same tool can later sit in front
of a Rust UTAS host and replay an identical captured request against both.
Two layers, as with the Blaze captures: raw/*.ofcap is exact bytes at mode
0600 and gitignored; sanitized/transactions.jsonl is the committed
artefact. Bodies are preserved EXACTLY and sanitised second -- only
known-secret headers and JSON keys are replaced, structure is never
reshaped, and every redaction is recorded in the transaction so a reader
knows what was touched.
Captured per transaction: connection id, sequence, relative and wall
time, elapsed ms, method, path, query, HTTP version, headers IN RECEIVED
ORDER as pairs (a dict would drop duplicates and ordering), raw body and
length for both directions, status, and observed keep-alive.
Verified as two independent properties, because they fail differently:
transparency (bytes through the proxy identical to bytes direct, Date
masked, with the mask asserted to have fired) and fidelity (parsed
transactions match what was sent, including a dechunked response and a
300-byte POST body). 5/5 mutations killed, including "record but do not
forward", "drop the last byte of every chunk" and "stop redacting".
scripts/test-utas-observe.py is committed alongside it: a capture tool
nobody can re-verify is not evidence.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
funman300