Support the WebSocket Denial Response ASGI extension (#1916)

Co-authored-by: Marcelo Trylesinski <[email protected]>

Author: kristjanvalur

tests/protocols/test_websocket.py

@@ -10,13 +10,16 @@
 from websockets.extensions.permessage_deflate import ClientPerMessageDeflateFactory
 from websockets.typing import Subprotocol
 
+from tests.response import Response
 from tests.utils import run_server
 from uvicorn._types import (
     ASGIReceiveCallable,
+    ASGIReceiveEvent,
     ASGISendCallable,
     Scope,
     WebSocketCloseEvent,
     WebSocketDisconnectEvent,
+    WebSocketResponseStartEvent,
 )
 from uvicorn.config import Config
 from uvicorn.protocols.websockets.websockets_impl import WebSocketProtocol
@@ -55,6 +58,21 @@ async def asgi(self):
                 break
 
 
+async def wsresponse(url):
+    """
+    A simple websocket connection request and response helper
+    """
+    url = url.replace("ws:", "http:")
+    headers = {
+        "connection": "upgrade",
+        "upgrade": "websocket",
+        "Sec-WebSocket-Key": "x3JJHMbDL1EzLkh9GBhXDw==",
+        "Sec-WebSocket-Version": "13",
+    }
+    async with httpx.AsyncClient() as client:
+        return await client.get(url, headers=headers)
+
+
 @pytest.mark.anyio
 async def test_invalid_upgrade(
     ws_protocol_cls: "typing.Type[WSProtocol | WebSocketProtocol]",
@@ -942,7 +960,10 @@ async def test_server_reject_connection(
     http_protocol_cls: "typing.Type[H11Protocol | HttpToolsProtocol]",
     unused_tcp_port: int,
 ):
+    disconnected_message: ASGIReceiveEvent = {}  # type: ignore
+
     async def app(scope: Scope, receive: ASGIReceiveCallable, send: ASGISendCallable):
+        nonlocal disconnected_message
         assert scope["type"] == "websocket"
 
         # Pull up first recv message.
@@ -955,15 +976,241 @@ async def app(scope: Scope, receive: ASGIReceiveCallable, send: ASGISendCallable
 
         # This doesn't raise `TypeError`:
         # See https://github.com/encode/uvicorn/issues/244
+        disconnected_message = await receive()
+
+    async def websocket_session(url):
+        with pytest.raises(websockets.exceptions.InvalidStatusCode) as exc_info:
+            async with websockets.client.connect(url):
+                pass  # pragma: no cover
+        assert exc_info.value.status_code == 403
+
+    config = Config(
+        app=app,
+        ws=ws_protocol_cls,
+        http=http_protocol_cls,
+        lifespan="off",
+        port=unused_tcp_port,
+    )
+    async with run_server(config):
+        await websocket_session(f"ws://127.0.0.1:{unused_tcp_port}")
+
+    assert disconnected_message == {"type": "websocket.disconnect", "code": 1006}
+
+
+@pytest.mark.anyio
+async def test_server_reject_connection_with_response(
+    ws_protocol_cls: "typing.Type[WSProtocol | WebSocketProtocol]",
+    http_protocol_cls: "typing.Type[H11Protocol | HttpToolsProtocol]",
+    unused_tcp_port: int,
+):
+    disconnected_message = {}
+
+    async def app(scope, receive, send):
+        nonlocal disconnected_message
+        assert scope["type"] == "websocket"
+        assert "websocket.http.response" in scope["extensions"]
+
+        # Pull up first recv message.
         message = await receive()
-        assert message["type"] == "websocket.disconnect"
+        assert message["type"] == "websocket.connect"
+
+        # Reject the connection with a response
+        response = Response(b"goodbye", status_code=400)
+        await response(scope, receive, send)
+        disconnected_message = await receive()
+
+    async def websocket_session(url):
+        response = await wsresponse(url)
+        assert response.status_code == 400
+        assert response.content == b"goodbye"
+
+    config = Config(
+        app=app,
+        ws=ws_protocol_cls,
+        http=http_protocol_cls,
+        lifespan="off",
+        port=unused_tcp_port,
+    )
+    async with run_server(config):
+        await websocket_session(f"ws://127.0.0.1:{unused_tcp_port}")
+
+    assert disconnected_message == {"type": "websocket.disconnect", "code": 1006}
+
+
+@pytest.mark.anyio
+async def test_server_reject_connection_with_multibody_response(
+    ws_protocol_cls: "typing.Type[WSProtocol | WebSocketProtocol]",
+    http_protocol_cls: "typing.Type[H11Protocol | HttpToolsProtocol]",
+    unused_tcp_port: int,
+):
+    disconnected_message: ASGIReceiveEvent = {}  # type: ignore
+
+    async def app(scope: Scope, receive: ASGIReceiveCallable, send: ASGISendCallable):
+        nonlocal disconnected_message
+        assert scope["type"] == "websocket"
+        assert "extensions" in scope
+        assert "websocket.http.response" in scope["extensions"]
+
+        # Pull up first recv message.
+        message = await receive()
+        assert message["type"] == "websocket.connect"
+        await send(
+            {
+                "type": "websocket.http.response.start",
+                "status": 400,
+                "headers": [
+                    (b"Content-Length", b"20"),
+                    (b"Content-Type", b"text/plain"),
+                ],
+            }
+        )
+        await send(
+            {
+                "type": "websocket.http.response.body",
+                "body": b"x" * 10,
+                "more_body": True,
+            }
+        )
+        await send({"type": "websocket.http.response.body", "body": b"y" * 10})
+        disconnected_message = await receive()
 
     async def websocket_session(url: str):
-        try:
+        response = await wsresponse(url)
+        assert response.status_code == 400
+        assert response.content == (b"x" * 10) + (b"y" * 10)
+
+    config = Config(
+        app=app,
+        ws=ws_protocol_cls,
+        http=http_protocol_cls,
+        lifespan="off",
+        port=unused_tcp_port,
+    )
+    async with run_server(config):
+        await websocket_session(f"ws://127.0.0.1:{unused_tcp_port}")
+
+    assert disconnected_message == {"type": "websocket.disconnect", "code": 1006}
+
+
+@pytest.mark.anyio
+async def test_server_reject_connection_with_invalid_status(
+    ws_protocol_cls: "typing.Type[WSProtocol | WebSocketProtocol]",
+    http_protocol_cls: "typing.Type[H11Protocol | HttpToolsProtocol]",
+    unused_tcp_port: int,
+):
+    # this test checks that even if there is an error in the response, the server
+    # can successfully send a 500 error back to the client
+    async def app(scope, receive, send):
+        assert scope["type"] == "websocket"
+        assert "websocket.http.response" in scope["extensions"]
+
+        # Pull up first recv message.
+        message = await receive()
+        assert message["type"] == "websocket.connect"
+
+        message = {
+            "type": "websocket.http.response.start",
+            "status": 700,  # invalid status code
+            "headers": [(b"Content-Length", b"0"), (b"Content-Type", b"text/plain")],
+        }
+        await send(message)
+        message = {
+            "type": "websocket.http.response.body",
+            "body": b"",
+        }
+        await send(message)
+
+    async def websocket_session(url):
+        response = await wsresponse(url)
+        assert response.status_code == 500
+        assert response.content == b"Internal Server Error"
+
+    config = Config(
+        app=app,
+        ws=ws_protocol_cls,
+        http=http_protocol_cls,
+        lifespan="off",
+        port=unused_tcp_port,
+    )
+    async with run_server(config):
+        await websocket_session(f"ws://127.0.0.1:{unused_tcp_port}")
+
+
+@pytest.mark.anyio
+async def test_server_reject_connection_with_body_nolength(
+    ws_protocol_cls: "typing.Type[WSProtocol | WebSocketProtocol]",
+    http_protocol_cls: "typing.Type[H11Protocol | HttpToolsProtocol]",
+    unused_tcp_port: int,
+):
+    # test that the server can send a response with a body but no content-length
+    async def app(scope: Scope, receive: ASGIReceiveCallable, send: ASGISendCallable):
+        assert scope["type"] == "websocket"
+        assert "extensions" in scope
+        assert "websocket.http.response" in scope["extensions"]
+
+        # Pull up first recv message.
+        message = await receive()
+        assert message["type"] == "websocket.connect"
+
+        await send(
+            {
+                "type": "websocket.http.response.start",
+                "status": 403,
+                "headers": [],
+            }
+        )
+        await send({"type": "websocket.http.response.body", "body": b"hardbody"})
+
+    async def websocket_session(url):
+        response = await wsresponse(url)
+        assert response.status_code == 403
+        assert response.content == b"hardbody"
+        if ws_protocol_cls == WSProtocol:  # pragma: no cover
+            # wsproto automatically makes the message chunked
+            assert response.headers["transfer-encoding"] == "chunked"
+        else:  # pragma: no cover
+            # websockets automatically adds a content-length
+            assert response.headers["content-length"] == "8"
+
+    config = Config(
+        app=app,
+        ws=ws_protocol_cls,
+        http=http_protocol_cls,
+        lifespan="off",
+        port=unused_tcp_port,
+    )
+    async with run_server(config):
+        await websocket_session(f"ws://127.0.0.1:{unused_tcp_port}")
+
+
+@pytest.mark.anyio
+async def test_server_reject_connection_with_invalid_msg(
+    ws_protocol_cls: "typing.Type[WSProtocol | WebSocketProtocol]",
+    http_protocol_cls: "typing.Type[H11Protocol | HttpToolsProtocol]",
+    unused_tcp_port: int,
+):
+    async def app(scope, receive, send):
+        assert scope["type"] == "websocket"
+        assert "websocket.http.response" in scope["extensions"]
+
+        # Pull up first recv message.
+        message = await receive()
+        assert message["type"] == "websocket.connect"
+
+        message = {
+            "type": "websocket.http.response.start",
+            "status": 404,
+            "headers": [(b"Content-Length", b"0"), (b"Content-Type", b"text/plain")],
+        }
+        await send(message)
+        # send invalid message.  This will raise an exception here
+        await send(message)
+
+    async def websocket_session(url):
+        with pytest.raises(websockets.exceptions.InvalidStatusCode) as exc_info:
             async with websockets.client.connect(url):
                 pass  # pragma: no cover
-        except Exception:
-            pass
+        assert exc_info.value.status_code == 404
 
     config = Config(
         app=app,
@@ -976,6 +1223,100 @@ async def websocket_session(url: str):
         await websocket_session(f"ws://127.0.0.1:{unused_tcp_port}")
 
 
+@pytest.mark.anyio
+async def test_server_reject_connection_with_missing_body(
+    ws_protocol_cls: "typing.Type[WSProtocol | WebSocketProtocol]",
+    http_protocol_cls: "typing.Type[H11Protocol | HttpToolsProtocol]",
+    unused_tcp_port: int,
+):
+    async def app(scope, receive, send):
+        assert scope["type"] == "websocket"
+        assert "websocket.http.response" in scope["extensions"]
+
+        # Pull up first recv message.
+        message = await receive()
+        assert message["type"] == "websocket.connect"
+
+        message = {
+            "type": "websocket.http.response.start",
+            "status": 404,
+            "headers": [(b"Content-Length", b"0"), (b"Content-Type", b"text/plain")],
+        }
+        await send(message)
+        # no further message
+
+    async def websocket_session(url):
+        with pytest.raises(websockets.exceptions.InvalidStatusCode) as exc_info:
+            async with websockets.client.connect(url):
+                pass  # pragma: no cover
+        assert exc_info.value.status_code == 404
+
+    config = Config(
+        app=app,
+        ws=ws_protocol_cls,
+        http=http_protocol_cls,
+        lifespan="off",
+        port=unused_tcp_port,
+    )
+    async with run_server(config):
+        await websocket_session(f"ws://127.0.0.1:{unused_tcp_port}")
+
+
+@pytest.mark.anyio
+async def test_server_multiple_websocket_http_response_start_events(
+    ws_protocol_cls: "typing.Type[WSProtocol | WebSocketProtocol]",
+    http_protocol_cls: "typing.Type[H11Protocol | HttpToolsProtocol]",
+    unused_tcp_port: int,
+):
+    """
+    The server should raise an exception if it sends multiple
+    websocket.http.response.start events.
+    """
+    exception_message: typing.Optional[str] = None
+
+    async def app(scope: Scope, receive: ASGIReceiveCallable, send: ASGISendCallable):
+        nonlocal exception_message
+        assert scope["type"] == "websocket"
+        assert "extensions" in scope
+        assert "websocket.http.response" in scope["extensions"]
+
+        # Pull up first recv message.
+        message = await receive()
+        assert message["type"] == "websocket.connect"
+
+        start_event: WebSocketResponseStartEvent = {
+            "type": "websocket.http.response.start",
+            "status": 404,
+            "headers": [(b"Content-Length", b"0"), (b"Content-Type", b"text/plain")],
+        }
+        await send(start_event)
+        try:
+            await send(start_event)
+        except Exception as exc:
+            exception_message = str(exc)
+
+    async def websocket_session(url: str):
+        with pytest.raises(websockets.exceptions.InvalidStatusCode) as exc_info:
+            async with websockets.client.connect(url):
+                pass
+        assert exc_info.value.status_code == 404
+
+    config = Config(
+        app=app,
+        ws=ws_protocol_cls,
+        http=http_protocol_cls,
+        lifespan="off",
+        port=unused_tcp_port,
+    )
+    async with run_server(config):
+        await websocket_session(f"ws://127.0.0.1:{unused_tcp_port}")
+
+    assert exception_message == (
+        "Expected ASGI message 'websocket.http.response.body' but got "
+        "'websocket.http.response.start'."
+    )
+
+
 @pytest.mark.anyio
 async def test_server_can_read_messages_in_buffer_after_close(
     ws_protocol_cls: "typing.Type[WSProtocol | WebSocketProtocol]",