open-swe/tests/test_linear_webhook_replay.py

"""Replay-window enforcement for Linear webhook signature verification (AUTHZ-001)."""

from __future__ import annotations

import hashlib
import hmac
import json
from datetime import UTC, datetime

from agent import webapp

_SECRET = "linear-signing-secret"


def _sign(body: bytes) -> str:
    return hmac.new(_SECRET.encode("utf-8"), body, hashlib.sha256).hexdigest()


def _now_ms() -> int:
    return int(datetime.now(UTC).timestamp() * 1000)


def test_fresh_timestamp_accepted() -> None:
    body = json.dumps({"type": "Comment", "webhookTimestamp": _now_ms()}).encode()
    assert webapp.verify_linear_signature(body, _sign(body), _SECRET) is True


def test_stale_timestamp_rejected() -> None:
    stale = _now_ms() - 10 * 60 * 1000  # 10 minutes old
    body = json.dumps({"type": "Comment", "webhookTimestamp": stale}).encode()
    # Signature is valid, but the timestamp is outside the freshness window.
    assert webapp.verify_linear_signature(body, _sign(body), _SECRET) is False


def test_future_timestamp_rejected() -> None:
    future = _now_ms() + 10 * 60 * 1000
    body = json.dumps({"type": "Comment", "webhookTimestamp": future}).encode()
    assert webapp.verify_linear_signature(body, _sign(body), _SECRET) is False


def test_missing_timestamp_rejected() -> None:
    body = json.dumps({"type": "Comment"}).encode()
    assert webapp.verify_linear_signature(body, _sign(body), _SECRET) is False


def test_non_numeric_timestamp_rejected() -> None:
    body = json.dumps({"type": "Comment", "webhookTimestamp": "not-a-number"}).encode()
    assert webapp.verify_linear_signature(body, _sign(body), _SECRET) is False


def test_bad_signature_rejected_even_when_fresh() -> None:
    body = json.dumps({"type": "Comment", "webhookTimestamp": _now_ms()}).encode()
    assert webapp.verify_linear_signature(body, "deadbeef", _SECRET) is False