Tightening the runtime type check for ssl (#7698)

Currently, the valid types of ssl parameter are SSLContext,
Literal[False], Fingerprint or None.

If user sets ssl = False, we disable ssl certificate validation which
makes total sense. But if user set ssl = True by mistake, instead of
enabling ssl certificate validation or raising errors, we silently
disable the validation too which is a little subtle but weird.

In this PR, we added a check that if user sets ssl=True, we enable
certificate validation by treating it as using Default SSL Context.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Sviatoslav Sydorenko <wk.cvs.github@sydorenko.org.ua>
Co-authored-by: Sam Bull <aa6bs0@sambull.org>
Co-authored-by: J. Nick Koston <nick@koston.org>
Co-authored-by: Sam Bull <git@sambull.org>

CHANGES/7698.feature

@@ -0,0 +1 @@
+Added support for passing `True` to `ssl` while deprecating `None`. -- by :user:`xiangyan99`

aiohttp/client.py

@@ -24,7 +24,6 @@
     Generic,
     Iterable,
     List,
-    Literal,
     Mapping,
     Optional,
     Set,
@@ -364,7 +363,7 @@ async def _request(
         proxy: Optional[StrOrURL] = None,
         proxy_auth: Optional[BasicAuth] = None,
         timeout: Union[ClientTimeout, _SENTINEL, None] = sentinel,
-        ssl: Optional[Union[SSLContext, Literal[False], Fingerprint]] = None,
+        ssl: Union[SSLContext, bool, Fingerprint] = True,
         server_hostname: Optional[str] = None,
         proxy_headers: Optional[LooseHeaders] = None,
         trace_request_ctx: Optional[SimpleNamespace] = None,
@@ -382,8 +381,8 @@ async def _request(
 
         if not isinstance(ssl, SSL_ALLOWED_TYPES):
             raise TypeError(
-                "ssl should be SSLContext, bool, Fingerprint, "
-                "or None, got {!r} instead.".format(ssl)
+                "ssl should be SSLContext, Fingerprint, or bool, "
+                "got {!r} instead.".format(ssl)
             )
 
         if data is not None and json is not None:
@@ -513,7 +512,7 @@ async def _request(
                         proxy_auth=proxy_auth,
                         timer=timer,
                         session=self,
-                        ssl=ssl,
+                        ssl=ssl if ssl is not None else True,  # type: ignore[redundant-expr]
                         server_hostname=server_hostname,
                         proxy_headers=proxy_headers,
                         traces=traces,
@@ -702,7 +701,7 @@ def ws_connect(
         headers: Optional[LooseHeaders] = None,
         proxy: Optional[StrOrURL] = None,
         proxy_auth: Optional[BasicAuth] = None,
-        ssl: Union[SSLContext, Literal[False], None, Fingerprint] = None,
+        ssl: Union[SSLContext, bool, Fingerprint] = True,
         server_hostname: Optional[str] = None,
         proxy_headers: Optional[LooseHeaders] = None,
         compress: int = 0,
@@ -725,7 +724,7 @@ def ws_connect(
                 headers=headers,
                 proxy=proxy,
                 proxy_auth=proxy_auth,
-                ssl=ssl,
+                ssl=ssl if ssl is not None else True,  # type: ignore[redundant-expr]
                 server_hostname=server_hostname,
                 proxy_headers=proxy_headers,
                 compress=compress,
@@ -750,7 +749,7 @@ async def _ws_connect(
         headers: Optional[LooseHeaders] = None,
         proxy: Optional[StrOrURL] = None,
         proxy_auth: Optional[BasicAuth] = None,
-        ssl: Union[SSLContext, Literal[False], None, Fingerprint] = None,
+        ssl: Union[SSLContext, bool, Fingerprint] = True,
         server_hostname: Optional[str] = None,
         proxy_headers: Optional[LooseHeaders] = None,
         compress: int = 0,
@@ -806,10 +805,19 @@ async def _ws_connect(
             extstr = ws_ext_gen(compress=compress)
             real_headers[hdrs.SEC_WEBSOCKET_EXTENSIONS] = extstr
 
+        # For the sake of backward compatibility, if user passes in None, convert it to True
+        if ssl is None:
+            warnings.warn(
+                "ssl=None is deprecated, please use ssl=True",
+                DeprecationWarning,
+                stacklevel=2,
+            )
+            ssl = True
+
         if not isinstance(ssl, SSL_ALLOWED_TYPES):
             raise TypeError(
-                "ssl should be SSLContext, bool, Fingerprint, "
-                "or None, got {!r} instead.".format(ssl)
+                "ssl should be SSLContext, Fingerprint, or bool, "
+                "got {!r} instead.".format(ssl)
             )
 
         # send request

aiohttp/client_exceptions.py

@@ -149,12 +149,12 @@ def port(self) -> Optional[int]:
         return self._conn_key.port
 
     @property
-    def ssl(self) -> Union[SSLContext, None, bool, "Fingerprint"]:
+    def ssl(self) -> Union[SSLContext, bool, "Fingerprint"]:
         return self._conn_key.ssl
 
     def __str__(self) -> str:
         return "Cannot connect to host {0.host}:{0.port} ssl:{1} [{2}]".format(
-            self, self.ssl if self.ssl is not None else "default", self.strerror
+            self, "default" if self.ssl is True else self.ssl, self.strerror
         )
 
     # OSError.__reduce__ does too much black magick
@@ -188,7 +188,7 @@ def path(self) -> str:
 
     def __str__(self) -> str:
         return "Cannot connect to unix socket {0.path} ssl:{1} [{2}]".format(
-            self, self.ssl if self.ssl is not None else "default", self.strerror
+            self, "default" if self.ssl is True else self.ssl, self.strerror
         )
 
 

aiohttp/client_reqrep.py

@@ -18,7 +18,6 @@
     Dict,
     Iterable,
     List,
-    Literal,
     Mapping,
     Optional,
     Tuple,
@@ -149,7 +148,7 @@ def check(self, transport: asyncio.Transport) -> None:
 if ssl is not None:
     SSL_ALLOWED_TYPES = (ssl.SSLContext, bool, Fingerprint, type(None))
 else:  # pragma: no cover
-    SSL_ALLOWED_TYPES = type(None)
+    SSL_ALLOWED_TYPES = (bool, type(None))
 
 
 @dataclasses.dataclass(frozen=True)
@@ -159,7 +158,7 @@ class ConnectionKey:
     host: str
     port: Optional[int]
     is_ssl: bool
-    ssl: Union[SSLContext, None, Literal[False], Fingerprint]
+    ssl: Union[SSLContext, bool, Fingerprint]
     proxy: Optional[URL]
     proxy_auth: Optional[BasicAuth]
     proxy_headers_hash: Optional[int]  # hash(CIMultiDict)
@@ -213,7 +212,7 @@ def __init__(
         proxy_auth: Optional[BasicAuth] = None,
         timer: Optional[BaseTimerContext] = None,
         session: Optional["ClientSession"] = None,
-        ssl: Union[SSLContext, Literal[False], Fingerprint, None] = None,
+        ssl: Union[SSLContext, bool, Fingerprint] = True,
         proxy_headers: Optional[LooseHeaders] = None,
         traces: Optional[List["Trace"]] = None,
         trust_env: bool = False,
@@ -248,7 +247,7 @@ def __init__(
             real_response_class = response_class
         self.response_class: Type[ClientResponse] = real_response_class
         self._timer = timer if timer is not None else TimerNoop()
-        self._ssl = ssl
+        self._ssl = ssl if ssl is not None else True  # type: ignore[redundant-expr]
         self.server_hostname = server_hostname
 
         if loop.get_debug():
@@ -290,7 +289,7 @@ def is_ssl(self) -> bool:
         return self.url.scheme in ("https", "wss")
 
     @property
-    def ssl(self) -> Union["SSLContext", None, Literal[False], Fingerprint]:
+    def ssl(self) -> Union["SSLContext", bool, Fingerprint]:
         return self._ssl
 
     @property

aiohttp/connector.py

@@ -746,7 +746,7 @@ def __init__(
         use_dns_cache: bool = True,
         ttl_dns_cache: Optional[int] = 10,
         family: int = 0,
-        ssl: Union[None, Literal[False], Fingerprint, SSLContext] = None,
+        ssl: Union[bool, Fingerprint, SSLContext] = True,
         local_addr: Optional[Tuple[str, int]] = None,
         resolver: Optional[AbstractResolver] = None,
         keepalive_timeout: Union[None, float, _SENTINEL] = sentinel,
@@ -769,8 +769,8 @@ def __init__(
 
         if not isinstance(ssl, SSL_ALLOWED_TYPES):
             raise TypeError(
-                "ssl should be SSLContext, bool, Fingerprint, "
-                "or None, got {!r} instead.".format(ssl)
+                "ssl should be SSLContext, Fingerprint, or bool, "
+                "got {!r} instead.".format(ssl)
             )
         self._ssl = ssl
         if resolver is None:
@@ -942,13 +942,13 @@ def _get_ssl_context(self, req: ClientRequest) -> Optional[SSLContext]:
             sslcontext = req.ssl
             if isinstance(sslcontext, ssl.SSLContext):
                 return sslcontext
-            if sslcontext is not None:
+            if sslcontext is not True:
                 # not verified or fingerprinted
                 return self._make_ssl_context(False)
             sslcontext = self._ssl
             if isinstance(sslcontext, ssl.SSLContext):
                 return sslcontext
-            if sslcontext is not None:
+            if sslcontext is not True:
                 # not verified or fingerprinted
                 return self._make_ssl_context(False)
             return self._make_ssl_context(True)

tests/test_client_exceptions.py

@@ -89,7 +89,7 @@ class TestClientConnectorError:
         host="example.com",
         port=8080,
         is_ssl=False,
-        ssl=None,
+        ssl=True,
         proxy=None,
         proxy_auth=None,
         proxy_headers_hash=None,
@@ -106,7 +106,7 @@ def test_ctor(self) -> None:
         assert err.os_error.strerror == "No such file"
         assert err.host == "example.com"
         assert err.port == 8080
-        assert err.ssl is None
+        assert err.ssl is True
 
     def test_pickle(self) -> None:
         err = client.ClientConnectorError(
@@ -123,7 +123,7 @@ def test_pickle(self) -> None:
             assert err2.os_error.strerror == "No such file"
             assert err2.host == "example.com"
             assert err2.port == 8080
-            assert err2.ssl is None
+            assert err2.ssl is True
             assert err2.foo == "bar"
 
     def test_repr(self) -> None:
@@ -141,7 +141,7 @@ def test_str(self) -> None:
             os_error=OSError(errno.ENOENT, "No such file"),
         )
         assert str(err) == (
-            "Cannot connect to host example.com:8080 ssl:" "default [No such file]"
+            "Cannot connect to host example.com:8080 ssl:default [No such file]"
         )
 
 
@@ -150,7 +150,7 @@ class TestClientConnectorCertificateError:
         host="example.com",
         port=8080,
         is_ssl=False,
-        ssl=None,
+        ssl=True,
         proxy=None,
         proxy_auth=None,
         proxy_headers_hash=None,

tests/test_client_request.py

@@ -164,7 +164,7 @@ def test_host_port_default_http(make_request: Any) -> None:
     req = make_request("get", "http://python.org/")
     assert req.host == "python.org"
     assert req.port == 80
-    assert not req.ssl
+    assert not req.is_ssl()
 
 
 def test_host_port_default_https(make_request: Any) -> None:
@@ -391,7 +391,7 @@ def test_ipv6_default_http_port(make_request: Any) -> None:
     req = make_request("get", "http://[2001:db8::1]/")
     assert req.host == "2001:db8::1"
     assert req.port == 80
-    assert not req.ssl
+    assert not req.is_ssl()
 
 
 def test_ipv6_default_https_port(make_request: Any) -> None:

tests/test_connector.py

@@ -31,19 +31,19 @@
 @pytest.fixture()
 def key():
     # Connection key
-    return ConnectionKey("localhost", 80, False, None, None, None, None)
+    return ConnectionKey("localhost", 80, False, True, None, None, None)
 
 
 @pytest.fixture
 def key2():
     # Connection key
-    return ConnectionKey("localhost", 80, False, None, None, None, None)
+    return ConnectionKey("localhost", 80, False, True, None, None, None)
 
 
 @pytest.fixture
 def ssl_key():
     # Connection key
-    return ConnectionKey("localhost", 80, True, None, None, None, None)
+    return ConnectionKey("localhost", 80, True, True, None, None, None)
 
 
 @pytest.fixture
@@ -1478,7 +1478,7 @@ async def test_cleanup_closed_disabled(loop: Any, mocker: Any) -> None:
 
 async def test_tcp_connector_ctor(loop: Any) -> None:
     conn = aiohttp.TCPConnector()
-    assert conn._ssl is None
+    assert conn._ssl is True
 
     assert conn.use_dns_cache
     assert conn.family == 0
@@ -1565,7 +1565,7 @@ async def test___get_ssl_context3(loop: Any) -> None:
     conn = aiohttp.TCPConnector(ssl=ctx)
     req = mock.Mock()
     req.is_ssl.return_value = True
-    req.ssl = None
+    req.ssl = True
     assert conn._get_ssl_context(req) is ctx
 
 
@@ -1591,7 +1591,7 @@ async def test___get_ssl_context6(loop: Any) -> None:
     conn = aiohttp.TCPConnector()
     req = mock.Mock()
     req.is_ssl.return_value = True
-    req.ssl = None
+    req.ssl = True
     assert conn._get_ssl_context(req) is conn._make_ssl_context(True)
 
 

tests/test_proxy.py

@@ -88,7 +88,7 @@ async def make_conn():
             auth=None,
             headers={"Host": "www.python.org"},
             loop=self.loop,
-            ssl=None,
+            ssl=True,
         )
 
         conn.close()
@@ -146,7 +146,7 @@ async def make_conn():
             auth=None,
             headers={"Host": "www.python.org", "Foo": "Bar"},
             loop=self.loop,
-            ssl=None,
+            ssl=True,
         )
 
         conn.close()