TieMeasureFlow/src/backend/tests/test_security.py

"""Security integration tests for FastAPI server.

Covers CORS, rate limiting, security headers, API key auth,
path traversal protection, filename sanitization, and OPTIONS preflight.
"""
import time
from unittest.mock import patch

import pytest
from httpx import AsyncClient

from src.backend.tests.conftest import _create_user, auth_headers


class TestCORSHeaders:
    """CORS header tests."""

    async def test_cors_headers_present(self, client: AsyncClient):
        """Response includes CORS headers for allowed origin."""
        resp = await client.get(
            "/api/health",
            headers={"Origin": "http://localhost:5000"},
        )
        assert resp.status_code == 200
        assert "access-control-allow-origin" in resp.headers


class TestSecurityHeaders:
    """Security header tests."""

    async def test_security_headers_present(self, client: AsyncClient):
        """Response includes all standard security headers."""
        resp = await client.get("/api/health")
        assert resp.status_code == 200
        assert resp.headers.get("x-content-type-options") == "nosniff"
        assert resp.headers.get("x-frame-options") == "DENY"
        assert resp.headers.get("x-xss-protection") == "1; mode=block"
        assert "strict-origin" in resp.headers.get("referrer-policy", "")
        assert "default-src" in resp.headers.get("content-security-policy", "")


class TestAPIKeyAuth:
    """API key authentication tests."""

    async def test_protected_endpoint_requires_api_key(self, client: AsyncClient):
        """Protected endpoint returns 401 without API key."""
        resp = await client.get("/api/users")
        assert resp.status_code == 401
        detail = resp.json().get("detail", "")
        assert "API key" in detail or "Missing" in detail

    async def test_invalid_api_key_returns_401(self, client: AsyncClient):
        """Invalid API key returns 401."""
        resp = await client.get(
            "/api/users",
            headers={"X-API-Key": "totally-invalid-key-12345"},
        )
        assert resp.status_code == 401
        detail = resp.json().get("detail", "")
        assert "Invalid" in detail or "inactive" in detail


class TestRateLimiting:
    """Rate limiting tests."""

    async def test_login_rate_limit_returns_429(self, client: AsyncClient, db_session):
        """Exceeding login rate limit returns 429."""
        # Default rate_limit_login = 5 per minute
        # Send 6 requests to exceed the limit
        for i in range(6):
            resp = await client.post(
                "/api/auth/login",
                json={"username": f"user{i}", "password": "pass"},
            )

        # The 6th request (or beyond) should be rate limited
        # Send one more to be sure
        resp = await client.post(
            "/api/auth/login",
            json={"username": "overflow", "password": "pass"},
        )
        assert resp.status_code == 429
        assert "Too many" in resp.json().get("detail", "")

    async def test_rate_limit_retry_after_header(self, client: AsyncClient):
        """429 response includes Retry-After header."""
        # Exhaust login rate limit
        for i in range(7):
            resp = await client.post(
                "/api/auth/login",
                json={"username": f"retry{i}", "password": "pass"},
            )

        # Final request should be 429 with Retry-After
        resp = await client.post(
            "/api/auth/login",
            json={"username": "retrycheck", "password": "pass"},
        )
        assert resp.status_code == 429
        assert "retry-after" in resp.headers
        retry_val = int(resp.headers["retry-after"])
        assert retry_val >= 1

    async def test_login_rate_limit_survives_rotated_x_forwarded_for(
        self, client: AsyncClient
    ):
        """A client rotating the spoofable (first) hop of XFF cannot dodge the
        login rate limit: with one trusted proxy (the default), the real
        client IP is the last hop, which stays constant."""
        for i in range(5):
            resp = await client.post(
                "/api/auth/login",
                json={"username": f"rotated{i}", "password": "pass"},
                headers={
                    "X-Forwarded-For": f"{i}.{i}.{i}.{i}, 198.51.100.42",
                },
            )
            assert resp.status_code == 401

        resp = await client.post(
            "/api/auth/login",
            json={"username": "rotated-overflow", "password": "pass"},
            headers={"X-Forwarded-For": "9.9.9.9, 198.51.100.42"},
        )
        assert resp.status_code == 429


class TestPathTraversal:
    """Path traversal protection in file endpoints."""

    async def test_path_traversal_blocked(self, client: AsyncClient, db_session):
        """Path traversal in file endpoint is blocked (403 or 404)."""
        user = await _create_user(
            db_session,
            username="fileuser",
            roles=["Maker", "MeasurementTec"],
        )

        resp = await client.get(
            "/api/files/../../etc/passwd",
            headers=auth_headers(user),
        )
        # Should be 403 (access denied) or 404 (not found), never 200
        assert resp.status_code in (403, 404)


class TestFilenameSanitization:
    """Filename sanitization tests."""

    async def test_dotfile_rejected(self, client: AsyncClient, db_session):
        """Filenames starting with '.' are rejected."""
        from src.backend.api.routers.files import sanitize_filename
        from fastapi import HTTPException

        with pytest.raises(HTTPException) as exc_info:
            sanitize_filename(".htaccess")
        assert exc_info.value.status_code == 400
        assert "." in exc_info.value.detail

    async def test_empty_filename_rejected(self, client: AsyncClient, db_session):
        """Empty filenames are rejected."""
        from src.backend.api.routers.files import sanitize_filename
        from fastapi import HTTPException

        with pytest.raises(HTTPException) as exc_info:
            sanitize_filename("///")
        assert exc_info.value.status_code == 400


class TestOptionsPreflight:
    """OPTIONS preflight request tests."""

    async def test_options_preflight(self, client: AsyncClient):
        """OPTIONS request returns CORS preflight headers."""
        resp = await client.options(
            "/api/health",
            headers={
                "Origin": "http://localhost:5000",
                "Access-Control-Request-Method": "GET",
                "Access-Control-Request-Headers": "X-API-Key",
            },
        )
        assert resp.status_code == 200
        assert "access-control-allow-methods" in resp.headers