Files
api/app/api/middleware/sanitizer.py
Roberto Musso 5753f8def9 refactor: remove storage, backup, plugin/marketplace features
- Delete app/storage/ (blob_store, vector_store, encryption)
- Delete app/marketplace/ (plugin_registry, plugin_review, revenue_share)
- Delete routes: backup.py, plugins.py, storage.py, vectors.py
- Relocate embed endpoint to POST /chat/embed
- Rewrite migration 001 (remove storage/plugin tables)
- Delete migration 002 (seed_plugins)
- Remove S3/Pinecone/Qdrant env vars from settings
- Remove storage/backup quotas from tier_manager
- Remove MinIO and Qdrant from docker-compose
- Delete tests: test_backup, test_plugins, test_storage
- Update README.md and clean .env.example
2026-04-08 00:47:37 +02:00

139 lines
4.7 KiB
Python

"""Response sanitizer middleware.
Scans JSON responses from the /api/v1/chat endpoint and strips any fragments
that could reveal server-side prompt IP:
- System prompt openers ("You are a/an/the …")
- Agent routing metadata ("Available agents:", "intent classifier", …)
- LangChain tool schema fragments (``"type": "function"``)
- Internal reasoning markers (<thinking>, <reasoning>, [INST], …)
- Exact-match known prompt fingerprints
The middleware only activates for paths under /api/v1/chat.
Any sanitisation event is logged as a WARNING with the request path and the
names of the fields that were modified.
"""
from __future__ import annotations
import json
import logging
import re
from fastapi import Request, Response
from starlette.middleware.base import BaseHTTPMiddleware
from starlette.types import ASGIApp
logger = logging.getLogger(__name__)
# ---------------------------------------------------------------------------
# Detection patterns — order matters: fingerprints checked first (exact),
# then compiled regexes.
# ---------------------------------------------------------------------------
_FINGERPRINTS: tuple[str, ...] = (
"You are an intent classifier",
"Respond with just the agent name",
"Summarize these agent results",
"Available agents:",
"route to:",
)
_PATTERNS: tuple[re.Pattern[str], ...] = (
re.compile(r"You are (a|an|the)\b.{0,200}", re.IGNORECASE | re.DOTALL),
re.compile(r"Available agents\s*:", re.IGNORECASE),
re.compile(r"\bintent classifier\b", re.IGNORECASE),
re.compile(r'"type"\s*:\s*"function"'), # LangChain tool schema
re.compile(r"<(thinking|reasoning|system|prompt)>", re.IGNORECASE),
re.compile(r"\[INST\]|\[/INST\]"), # Llama instruct markers
re.compile(r"route\s+to\s*:", re.IGNORECASE),
re.compile(r"prompt_template\s*:\s*['\"].{10,}", re.IGNORECASE),
)
def _sanitize_text(text: str) -> tuple[str, bool]:
"""Scan *text* for prompt fragments and replace matches with ``[REDACTED]``.
Returns ``(cleaned_text, was_changed)``.
"""
# Fingerprint check — if any exact phrase is present, redact the whole string.
for fp in _FINGERPRINTS:
if fp in text:
return "[REDACTED]", True
changed = False
for pattern in _PATTERNS:
new_text, n = pattern.subn("[REDACTED]", text)
if n:
text = new_text
changed = True
return text, changed
class SanitizerMiddleware(BaseHTTPMiddleware):
"""Strip prompt IP from /api/v1/chat JSON responses."""
def __init__(self, app: ASGIApp) -> None:
super().__init__(app)
async def dispatch(self, request: Request, call_next) -> Response: # type: ignore[override]
response: Response = await call_next(request)
# Only process chat endpoint responses.
if not request.url.path.startswith("/api/v1/chat"):
return response
# Read body — collect streaming chunks.
body_bytes = b""
async for chunk in response.body_iterator:
body_bytes += chunk if isinstance(chunk, bytes) else chunk.encode()
# Skip non-JSON bodies (shouldn't happen on /chat, but be safe).
try:
body = json.loads(body_bytes.decode("utf-8"))
except (json.JSONDecodeError, UnicodeDecodeError):
return Response(
content=body_bytes,
status_code=response.status_code,
headers=dict(response.headers),
media_type=response.media_type,
)
if not isinstance(body, dict):
return Response(
content=body_bytes,
status_code=response.status_code,
headers=dict(response.headers),
media_type=response.media_type,
)
# Walk top-level string fields and sanitise.
sanitised_fields: list[str] = []
for key, value in body.items():
if isinstance(value, str):
cleaned, changed = _sanitize_text(value)
if changed:
body[key] = cleaned
sanitised_fields.append(key)
if sanitised_fields:
logger.warning(
"Sanitizer redacted prompt fragments",
extra={
"path": request.url.path,
"fields": sanitised_fields,
},
)
new_body = json.dumps(body).encode("utf-8")
headers = dict(response.headers)
headers["content-length"] = str(len(new_body))
return Response(
content=new_body,
status_code=response.status_code,
headers=headers,
media_type="application/json",
)