Files
FabledScribe/tests/test_retrieval_query_scrubbing.py
T
bvandeusenandClaude Opus 5 bfa2d419f9 fix(telemetry): a logged query never carries a credential (#3925)
pre_tool_rule retrieves against the RAW COMMAND TEXT and write_path_rule
against the code being written, so whatever was on the command line or in
the buffer is what record_retrieval stored in retrieval_logs.query. A
command that exported a token stored the token.

Storing it was not the worst of it. near_miss_samples is the readout the
threshold docs tell you to open before moving a bar, so the value came back
OUT into an agent's context on the next tuning pass — which is exactly how
this was found, mid-way through #3853's threshold spike.

SCRUBBED ON WRITE, at _build_payload — the single seam every source reaches
the column through. A read-side filter would leave the secret in the table
where a backup or a debug query still reaches it, and a per-caller scrub
would be three places for one to be forgotten by whoever adds the fourth
arm.

REDACTED VISIBLY. `[redacted:<kind>]` rather than a silent deletion: a
reader who cannot tell a scrubbed query from a short one is being lied to
by the readout itself.

DELIBERATELY CONSERVATIVE — vendor-prefixed credentials, values assigned to
secret-NAMED variables, auth headers, PEM blocks. Things that are secrets by
construction. Entropy heuristics and long-opaque-string detection start
eating real queries, and a query is evidence: missing an exotic secret costs
one redaction nobody made, while eating a query costs the ability to tune
the bar at all.

The guard pins BOTH directions, and the second half is the one that matters.
A scrubber that eats evidence fails silently — it keeps looking like it
works while turning the one instrument for tuning a threshold into
unreadable stubs, which is the #2663 shape in a new place. So nine REAL
queries from this install's near-miss samples must survive byte for byte. If
a future pattern touches one, the pattern is too greedy.

Verified against the real shapes before commit: six credential formats
redacted (fabricated values), nine real queries unchanged, and the payload
seam confirmed to store "export API_TOKEN=[redacted:assigned] && git push".

This does NOT scrub rows already written. Purging those is separate.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011cPyzNnegXHr5iRMzzy5KJ
2026-09-11 15:38:40 -04:00

129 lines
5.6 KiB
Python

"""A logged query never carries a credential (#3925).
WHY THIS EXISTS
`pre_tool_rule` retrieves against the RAW COMMAND TEXT and `write_path_rule`
against the code being written, so whatever was on the command line or in the
buffer is what `record_retrieval` stores in `retrieval_logs.query`. A command
that exported a token therefore stored the token.
And storing it was not the worst of it. `near_miss_samples` is the readout the
threshold documentation tells you to open before moving a bar, so the value
came back OUT into an agent's context on the next tuning pass — which is
exactly how this was found, during #3853's threshold spike.
WHAT THIS PINS, IN BOTH DIRECTIONS, AND WHY THE SECOND HALF IS THE HARD ONE
A scrubber has two ways to fail and only one of them is obvious.
1. It misses a secret. Caught by the redaction cases below.
2. It eats the EVIDENCE. This is the failure that would do more damage,
because it is silent: the whole worth of a near-miss sample is reading the
query that was actually refused, and a scrubber that chewed up ordinary
commands would turn the one instrument for tuning a bar into unreadable
stubs while still looking like it worked. That is the #2663 shape — a
surface that reads fine and has quietly stopped saying anything.
So the second block is not padding. Its cases are REAL queries taken from this
install's `near_miss_samples` during #3853, and they must survive byte for
byte. If a future pattern is added and one of them changes, the pattern is too
greedy — tighten it rather than editing the expectation.
The secret cases use FABRICATED values in the real formats. Nothing here is or
was a live credential.
"""
import pytest
from scribe.services.retrieval_telemetry import scrub_secrets
# Fabricated, in the shapes that actually occur. The first is the shape that
# was found stored: a shell assignment of a vendor-prefixed token.
_SECRETS = [
("vendor-prefixed token in a shell assignment",
"TOK=flt_AAAABBBBCCCCDDDDEEEEFFFF\npython3 - <<'PY'",
"flt_AAAABBBBCCCCDDDDEEEEFFFF"),
("a Scribe fmcp_ key in an auth header",
"curl -H 'Authorization: Bearer fmcp_ZZZZYYYYXXXXWWWWVVVV' https://x",
"fmcp_ZZZZYYYYXXXXWWWWVVVV"),
("a forge token in an export",
"export GITHUB_TOKEN=ghp_1234567890abcdefghijABCDEF",
"ghp_1234567890abcdefghijABCDEF"),
("a value assigned to a secret-named variable",
'REGISTRY_PASSWORD="hunter2-correct-horse"',
"hunter2-correct-horse"),
("an api_key in a query string",
"curl 'https://api.example/v1/things?api_key=abcdef1234567890'",
"abcdef1234567890"),
("a private key block",
"-----BEGIN RSA PRIVATE KEY-----\nMIIEowIBAAKC\n-----END RSA PRIVATE KEY-----",
"MIIEowIBAAKC"),
]
# Real queries, from this install's near-miss samples during #3853.
_EVIDENCE = [
"git push origin dev",
'git pull --rebase origin dev 2>&1 | tail -3; echo "=== HEAD ==="; git log --oneline -2',
"python3 - <<'PY'\nimport pathlib\np = pathlib.Path(\"web/src/routes/admin/tuning/tuning.test.ts\")",
"docker compose up -d",
'package library\n\nimport (\n\t"context"\n\t"fmt"\n)',
"import {\n fetchTransfers,\n retryTransfer,\n} from './api'",
'grep -rn "useState" src/components/ | head -20',
# The word "token" in ordinary prose is not a token.
"explain how the token bucket rate limiter works",
"wc -l src/*.py && date",
]
@pytest.mark.parametrize(("label", "text", "secret"), _SECRETS,
ids=[c[0] for c in _SECRETS])
def test_a_credential_never_survives_into_the_query_column(label, text, secret):
"""The value goes; something visible stays in its place."""
out = scrub_secrets(text)
assert secret not in out, (
f"{label}: the credential is still in the text that would be stored"
)
assert "[redacted" in out, (
f"{label}: the span was removed without saying so. A silent deletion "
"leaves a reader unable to tell a scrubbed query from a short one, "
"which is the readout lying about itself rather than protecting you."
)
@pytest.mark.parametrize("query", _EVIDENCE)
def test_an_ordinary_query_is_stored_exactly_as_it_was(query):
"""Evidence survives byte for byte.
These came out of real `near_miss_samples`. A threshold is tuned by reading
them, so a pattern greedy enough to touch one has destroyed the instrument
it was meant to make safe — tighten the pattern, never this expectation.
"""
assert scrub_secrets(query) == query
def test_empty_and_missing_queries_pass_through():
"""Some sources log no query at all; scrubbing must not invent one."""
assert scrub_secrets(None) is None
assert scrub_secrets("") == ""
def test_the_write_path_scrubs_rather_than_the_read_path():
"""The payload built for storage carries the redacted text (#3925).
Pinned on `_build_payload` because that is the single seam every source
reaches the column through. A per-caller scrub would be three places for
one of them to be forgotten by whoever adds the fourth arm — and the one
forgotten would be the one that stored a secret.
"""
from scribe.services.retrieval_telemetry import _build_payload
payload = _build_payload(
user_id=1, source="pre_tool_rule",
query="export API_TOKEN=ghp_1234567890abcdefghijABCDEF && git push",
threshold=0.68, limit=5, project_id=0, is_task=None,
results=[], duration_ms=1.0,
)
assert "ghp_1234567890abcdefghijABCDEF" not in payload["query"]
assert "[redacted" in payload["query"]
# The rest of the command survives, or the row stops being evidence.
assert "git push" in payload["query"]