WebDAV sync support, access tokens, REST control endpoints (#10)

Implement complete WebDAV file serving compatible with various clients from Windows File Explorer to more specialized sync tools. The old control WebSocket has been updated to part-DAV, part REST API instead. Implemented user:pass BASIC auth. Added UI and backend for creating tokens that avoid the need to use actual username and password for requests from CLI or DAV.

tests/test_files_path_security.py

@@ -0,0 +1,169 @@
+"""Path traversal and percent-encoding security tests for the fileserver."""
+from pathlib import Path
+from uuid import uuid4
+
+import pytest
+import pytest_asyncio
+from sanic import Sanic
+
+from cista import config, watching
+from cista.fileserver import bp as fileserver_bp
+
+
+@pytest.fixture()
+def setup_storage(tmp_path: Path):
+    config.config = config.Config(path=tmp_path, listen=":0", public=True)
+    watching.state.root = []
+    watching.rootpath = tmp_path
+    yield tmp_path
+    watching.state.root = []
+
+
+@pytest_asyncio.fixture()
+async def client(setup_storage: Path):
+    app = Sanic(f"files-path-sec-test-{uuid4().hex}", strict_slashes=True)
+    app.router.ALLOWED_METHODS = (*app.router.ALLOWED_METHODS, "MKCOL", "MOVE", "COPY", "PROPFIND")
+    app.blueprint(fileserver_bp)
+    yield app.asgi_client
+
+
+# ---------------------------------------------------------------------------
+# %2F — encoded slash should be decoded as a path separator
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_get_percent2F_decoded_as_path_separator(client, setup_storage: Path):
+    """%2F in the URL path is decoded to '/' and treated as a path separator."""
+    (setup_storage / "sub").mkdir()
+    (setup_storage / "sub" / "file.txt").write_text("hello", encoding="utf-8")
+
+    _, res = await client.get("/files/sub%2Ffile.txt")
+
+    assert res.status_code == 200
+    assert res.text == "hello"
+
+
+@pytest.mark.asyncio
+async def test_mkcol_percent2F_creates_nested_directory(client, setup_storage: Path):
+    """%2F in MKCOL path is decoded as a separator, creating nested dirs."""
+    _, res = await client.request("MKCOL", "/files/parent%2Fchild")
+
+    assert res.status_code == 201
+    assert (setup_storage / "parent" / "child").is_dir()
+
+
+# ---------------------------------------------------------------------------
+# %20 — encoded space in filename
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_get_percent20_in_filename(client, setup_storage: Path):
+    (setup_storage / "my file.txt").write_text("spaced", encoding="utf-8")
+
+    _, res = await client.get("/files/my%20file.txt")
+
+    assert res.status_code == 200
+    assert res.text == "spaced"
+
+
+@pytest.mark.asyncio
+async def test_mkcol_percent20_in_folder_name(client, setup_storage: Path):
+    _, res = await client.request("MKCOL", "/files/my%20folder")
+
+    assert res.status_code == 201
+    assert (setup_storage / "my folder").is_dir()
+
+
+# ---------------------------------------------------------------------------
+# Path traversal — .. and encoded variants
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_get_dotdot_rejected(client):
+    """.. is path-normalised by the router before reaching the handler."""
+    _, res = await client.get("/files/..")
+    assert res.status_code in (400, 404)
+
+
+@pytest.mark.asyncio
+async def test_get_dotdot_segment_rejected(client):
+    """Traversal via sub/../.. is path-normalised by the router."""
+    _, res = await client.get("/files/sub/../..")
+    assert res.status_code in (400, 404)
+
+
+@pytest.mark.asyncio
+async def test_get_encoded_dotdot_rejected(client):
+    """%2E%2E (encoded ..) must be rejected."""
+    _, res = await client.get("/files/%2E%2E")
+    assert res.status_code == 400
+
+
+@pytest.mark.asyncio
+async def test_get_encoded_dotdot_segment_rejected(client):
+    """%2E%2E used as a segment in a longer path must be rejected."""
+    _, res = await client.get("/files/sub%2F%2E%2E%2F..%2Fetc%2Fpasswd")
+    assert res.status_code == 400
+
+
+@pytest.mark.asyncio
+async def test_mkcol_dotdot_rejected(client):
+    _, res = await client.request("MKCOL", "/files/..")
+    assert res.status_code in (400, 404)
+
+
+@pytest.mark.asyncio
+async def test_delete_dotdot_rejected(client):
+    _, res = await client.delete("/files/..")
+    assert res.status_code in (400, 404)
+
+
+# ---------------------------------------------------------------------------
+# Dot-prefixed filenames (.hidden, ...)
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_get_hidden_file_rejected(client):
+    """Names starting with '.' are not allowed."""
+    _, res = await client.get("/files/.hidden")
+    assert res.status_code == 400
+
+
+@pytest.mark.asyncio
+async def test_mkcol_hidden_folder_rejected(client):
+    _, res = await client.request("MKCOL", "/files/.secret")
+    assert res.status_code == 400
+
+
+# ---------------------------------------------------------------------------
+# Windows-style drive paths (c:/) — safe on Linux, stays inside storage root
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_mkcol_windows_drive_path_stays_within_root(client, setup_storage: Path):
+    """A Windows-style drive path like 'c:/foo' is treated as a relative path
+    on Linux and resolves safely inside the storage root."""
+    _, res = await client.request("MKCOL", "/files/c:/secret")
+
+    # Either created inside the storage root (201) or sanitised away (400/404).
+    # The important assertion: nothing was created outside the storage root.
+    assert not (Path("/c:") / "secret").exists()
+    assert not (Path("c:/secret")).exists()
+    if res.status_code == 201:
+        # Created safely inside tmp storage
+        assert (setup_storage / "c:" / "secret").is_dir()
+
+
+@pytest.mark.asyncio
+async def test_mkcol_backslash_in_path_sanitised(client, setup_storage: Path):
+    """Backslashes are replaced with dashes, not treated as path separators."""
+    _, res = await client.request("MKCOL", "/files/foo\\..\\bar")
+
+    assert res.status_code in (201, 400)
+    # Must not escape storage root
+    assert not (setup_storage.parent / "bar").exists()