Files
DoorCounter/server/camera_endpoint.py
Peter Woolery 641ab29277 fix(server): reject inverted period_start/period_end in CameraRecord
A misbehaving or clock-broken device could submit period_end <=
period_start, polluting the camera_records table with zero-length or
inverted windows that corrupt downstream hourly analytics. Add a
Pydantic model_validator so the request is rejected at the API
boundary instead of silently persisting bad ranges.

Found via adversarial review (run 2026-05-01-191359, both reviewers).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-01 15:44:57 -07:00

76 lines
2.4 KiB
Python

# server/camera_endpoint.py
# Add these models and endpoint to the server's main.py alongside the existing BLE endpoints.
# Requires: camera_records table (see migrations/004_camera_records.sql)
#
# IMPORTANT: Before deploying, verify the HMAC message format in verify_device_hmac
# matches what the firmware computes:
# HMAC-SHA256(secret, f"{device_id}:{timestamp}:{sha256_hex(body)}")
# Headers expected: X-Device-Id, X-Timestamp, X-HMAC-Signature
import sqlite3
from typing import List
from fastapi import Depends
from pydantic import BaseModel, Field, model_validator
class CameraRecord(BaseModel):
period_start: int
period_end: int
entries: int = Field(ge=0)
exits: int = Field(ge=0)
@model_validator(mode="after")
def _period_order(self):
if self.period_end <= self.period_start:
raise ValueError("period_end must be strictly greater than period_start")
return self
class CameraEventsRequest(BaseModel):
location_id: str
records: List[CameraRecord]
class CameraEventsResponse(BaseModel):
status: str
accepted: int
# Add this endpoint to your FastAPI app (alongside receive_batch_events):
#
# @app.post("/api/v1/camera/events/batch", response_model=CameraEventsResponse)
# async def receive_camera_events(
# batch: CameraEventsRequest,
# device_id: str = Depends(verify_device_hmac),
# db: sqlite3.Connection = Depends(get_db),
# ):
def receive_camera_events_impl(
batch: CameraEventsRequest,
device_id: str,
db: sqlite3.Connection,
) -> CameraEventsResponse:
"""Receive hourly camera entry/exit records; idempotent on (device_id, period_start)."""
cursor = db.cursor()
accepted = 0
for record in batch.records:
try:
cursor.execute(
"""INSERT INTO camera_records
(device_id, location_id, period_start, period_end, entries, exits)
VALUES (?, ?, ?, ?, ?, ?)""",
(
device_id,
batch.location_id,
record.period_start,
record.period_end,
record.entries,
record.exits,
),
)
accepted += 1
except sqlite3.IntegrityError:
pass # duplicate (device_id, period_start) — idempotent
db.commit()
return CameraEventsResponse(status="ok", accepted=accepted)