Files
hermes-agent/hermes_cli/debug_redaction.py
kshitijk4poor f5a9361dcc fix(debug): stop encoded URL param keys at encoded separators
Review finding (BR1 r3 efficiency, Low): the _ENCODED_URL_PARAM_RE key
group excluded only `%3D`, so a key could run across `%26`/`%3F`/`%23`/
`%3B`. Two consequences: a nested `?next=%2Fx%3Ffoo%26token%3D<secret>`
matched the key `foo%26token`, which is not a sensitive name, and the
secret leaked; and each separator restarted a match that scanned up to
160 chars, about 8x slower than base on 1 MiB of `%26a` (1.72s vs 0.21s;
0.36s now).

Exclude every encoded separator from the key so it ends at the nearest
one. The nested leak now redacts to `%3D%2A%2A%2A`, and the
`redirect=...%3Fapi_key%3D...` case is unchanged.
2026-10-03 21:15:17 +05:30

188 lines
7.2 KiB
Python

"""Fail-closed redaction for text and structures leaving debug/support flows."""
from __future__ import annotations
import re
from agent.redact import (
_SENSITIVE_QUERY_PARAMS,
REDACTION_UNAVAILABLE,
SECRET_HEADER_NAME_LIST,
_canonical_url_param_name,
redact_sensitive_text,
)
_REDACTED = "[REDACTED]"
_EMAIL_ADDRESS_RE = re.compile(
r"(?<![A-Za-z0-9._%+-])"
r"[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}"
r"(?![A-Za-z0-9._%+-])"
)
# Support uploads are a strict opt-in surface: agent.redact's query-param names
# plus a few support-only extras, compared by compact name so snake_case,
# kebab-case and camelCase match without widening ordinary tool-output redaction.
_SENSITIVE_URL_PARAM_NAMES = frozenset(
"".join(ch for ch in name if ch.isalnum()) for name in _SENSITIVE_QUERY_PARAMS
) | {"authtoken", "privatekey", "secretkey", "xamzsecuritytoken", "securitytoken"}
_RAW_URL_PARAM_RE = re.compile(
r"(?P<sep>[?#&;])(?P<key>[A-Za-z0-9_.~+%\-]+)="
r"(?P<value>[^?#&;\s\"'<>]*)"
)
_ENCODED_URL_PARAM_RE = re.compile(
r"(?P<sep>%3[fF]|%23|%26|%3[bB])"
r"(?P<key>(?:(?!%3[dD]|%3[fF]|%23|%26|%3[bB])[^\s\"'<>]){1,160}?)"
r"(?P<eq>%3[dD]|=)"
r"(?P<value>.*?)"
r"(?=(?:%3[fF]|%26|%23|%3[bB])|[\s\"'<>]|$)",
re.IGNORECASE,
)
_SENSITIVE_HEADER_NAMES = (
"authorization",
"proxy-authorization",
"cookie",
"set-cookie",
*SECRET_HEADER_NAME_LIST,
)
_HEADER_NAME_PATTERN = "|".join(re.escape(name) for name in _SENSITIVE_HEADER_NAMES)
_QUOTED_HEADER_RE = re.compile(
rf"(?P<prefix>['\"]?(?:{_HEADER_NAME_PATTERN})['\"]?\s*[:=]\s*)"
r"(?P<quote>['\"])(?P<value>.*?)(?P=quote)",
re.IGNORECASE,
)
_BARE_HEADER_RE = re.compile(
rf"(?P<prefix>\b(?:{_HEADER_NAME_PATTERN})\b\s*[:=]\s*)"
# agent.redact masks the scheme of ``x-api-key: Basic <key>`` to ``***`` and
# keeps the key, so ``***`` before a same-line token-shaped value (not prose
# and not another secret header) is a scheme too, and the key is the value.
r"(?P<value>(?>(?:(?:Bearer|Basic|Digest)\s+|\*\*\*[ \t]+(?=[A-Za-z0-9._~+/-]{8,}=*(?![A-Za-z0-9._~+/=-]))"
rf"(?!(?:{_HEADER_NAME_PATTERN})\b\s*[:=]))?)(?!\[REDACTED\])[^\s,}}\]]+)",
re.IGNORECASE,
)
_SECRET_ARG_FLAG = (
r"--(?:api[-_]?key|access[-_]?token|refresh[-_]?token|id[-_]?token|"
r"auth[-_]?token|client[-_]?secret|private[-_]?key|secret[-_]?key|"
r"password|passwd|credential|token|secret)"
)
_QUOTED_ARGV_RE = re.compile(
rf"(?P<flag_quote>['\"])(?P<flag>{_SECRET_ARG_FLAG})(?P=flag_quote)"
r"(?P<sep>\s*,\s*)"
r"(?P<value_quote>['\"])(?P<value>.*?)(?P=value_quote)",
re.IGNORECASE,
)
_ARG_EQUALS_RE = re.compile(
rf"(?P<flag>{_SECRET_ARG_FLAG})(?P<sep>\s*=\s*)"
r"(?P<quote>['\"]?)(?!\[REDACTED\])(?P<value>[^\s,}\]'\"]+)(?P=quote)",
re.IGNORECASE,
)
_ARG_OPERAND_RE = re.compile(
rf"(?P<flag>{_SECRET_ARG_FLAG})(?P<sep>\s+)"
r"(?P<quote>['\"]?)(?!\[REDACTED\])(?P<value>[^\s,}\]'\"]+)(?P=quote)",
re.IGNORECASE,
)
_HEADER_ARGV_RE = re.compile(
r"(?P<head_quote>['\"])--header(?P=head_quote)\s*,\s*"
rf"(?P<name_quote>['\"])(?P<name>{_HEADER_NAME_PATTERN})(?P=name_quote)\s*,\s*"
r"(?:(?P<scheme_quote>['\"])(?P<scheme>Bearer|Basic|Digest)(?P=scheme_quote)\s*,\s*)?"
r"(?P<value_quote>['\"])(?P<value>.*?)(?P=value_quote)",
re.IGNORECASE,
)
_PLAIN_HEADER_ARG_RE = re.compile(
rf"(?P<prefix>--header\s+(?:{_HEADER_NAME_PATTERN})\s+)"
r"(?>(?:(?:Bearer|Basic|Digest)\s+)?)(?!\[REDACTED\])(?P<value>[^\s,}\]]+)",
re.IGNORECASE,
)
_SUPPORT_BEARER_RE = re.compile(
r"(?P<prefix>\bBearer\s+)[A-Za-z0-9._~+/-]{8,}=*",
re.IGNORECASE,
)
def _decoded_compact_name(value: object) -> str:
return "".join(ch for ch in _canonical_url_param_name(str(value or "")) if ch.isalnum())
def _redact_url_params(text: str) -> str:
def _raw_sub(match: re.Match[str]) -> str:
if _decoded_compact_name(match.group("key")) not in _SENSITIVE_URL_PARAM_NAMES:
return match.group(0)
return f"{match.group('sep')}{match.group('key')}=***"
def _encoded_sub(match: re.Match[str]) -> str:
if _decoded_compact_name(match.group("key")) not in _SENSITIVE_URL_PARAM_NAMES:
return match.group(0)
replacement = "%2A%2A%2A" if match.group("eq").lower() == "%3d" else "***"
return f"{match.group('sep')}{match.group('key')}{match.group('eq')}{replacement}"
# Running until stable handles a raw URL nested inside another query value
# without recursive parsing. The pass cap keeps malformed input bounded.
for _ in range(4):
redacted = _ENCODED_URL_PARAM_RE.sub(_encoded_sub, _RAW_URL_PARAM_RE.sub(_raw_sub, text))
if redacted == text:
break
text = redacted
return text
def _redact_headers_and_argv(text: str) -> str:
text = _QUOTED_HEADER_RE.sub(
lambda match: f"{match.group('prefix')}{match.group('quote')}{_REDACTED}{match.group('quote')}",
text,
)
text = _BARE_HEADER_RE.sub(lambda match: f"{match.group('prefix')}{_REDACTED}", text)
text = _HEADER_ARGV_RE.sub(
lambda match: (
f"{match.group('head_quote')}--header{match.group('head_quote')}, "
f"{match.group('name_quote')}{match.group('name')}{match.group('name_quote')}, "
+ (
f"{match.group('scheme_quote')}{match.group('scheme')}{match.group('scheme_quote')}, "
if match.group("scheme")
else ""
)
+ f"{match.group('value_quote')}{_REDACTED}{match.group('value_quote')}"
),
text,
)
text = _QUOTED_ARGV_RE.sub(
lambda match: (
f"{match.group('flag_quote')}{match.group('flag')}{match.group('flag_quote')}"
f"{match.group('sep')}{match.group('value_quote')}{_REDACTED}{match.group('value_quote')}"
),
text,
)
text = _ARG_EQUALS_RE.sub(
lambda match: f"{match.group('flag')}{match.group('sep')}{match.group('quote')}{_REDACTED}{match.group('quote')}",
text,
)
text = _ARG_OPERAND_RE.sub(
lambda match: f"{match.group('flag')}{match.group('sep')}{match.group('quote')}{_REDACTED}{match.group('quote')}",
text,
)
text = _PLAIN_HEADER_ARG_RE.sub(
lambda match: f"{match.group('prefix')}{_REDACTED}", text
)
return _SUPPORT_BEARER_RE.sub(
lambda match: f"{match.group('prefix')}{_REDACTED}", text
)
def redact_debug_support_text(value: object, *, max_chars: int | None = None) -> str:
"""Strictly scrub one debug/support value, then apply an optional character cap.
This is deliberately stricter than ordinary model/tool output: support text is
leaving the process for a human or remote diagnostics store. Any redactor
failure returns the shared fail-closed sentinel rather than the original.
"""
text = "" if value is None else str(value)
if not text:
return text
try:
text = redact_sensitive_text(text, force=True, redact_url_credentials=True)
text = _redact_url_params(text)
text = _redact_headers_and_argv(text)
text = _EMAIL_ADDRESS_RE.sub("[REDACTED_EMAIL]", text)
except Exception:
return REDACTION_UNAVAILABLE
return text[:max_chars] if max_chars is not None else text