Support using netrc for non-proxy HTTP credentials

aiohttp/client.py

@@ -492,6 +492,7 @@ async def _request(
                         ssl=ssl,
                         proxy_headers=proxy_headers,
                         traces=traces,
+                        trust_env=self.trust_env,
                     )
 
                     # connection timeout

aiohttp/client_reqrep.py

@@ -44,7 +44,9 @@
     BasicAuth,
     HeadersMixin,
     TimerNoop,
+    basicauth_from_netrc,
     is_expected_content_type,
+    netrc_from_env,
     noop,
     parse_mimetype,
     reify,
@@ -210,6 +212,7 @@ def __init__(
         ssl: Union[SSLContext, bool, Fingerprint, None] = None,
         proxy_headers: Optional[LooseHeaders] = None,
         traces: Optional[List["Trace"]] = None,
+        trust_env: bool = False,
     ):
         match = _CONTAINS_CONTROL_CHAR_RE.search(method)
         if match:
@@ -251,7 +254,7 @@ def __init__(
         self.update_auto_headers(skip_auto_headers)
         self.update_cookies(cookies)
         self.update_content_encoding(data)
-        self.update_auth(auth)
+        self.update_auth(auth, trust_env)
         self.update_proxy(proxy, proxy_auth, proxy_headers)
 
         self.update_body_from_data(data)
@@ -428,11 +431,20 @@ def update_transfer_encoding(self) -> None:
             if hdrs.CONTENT_LENGTH not in self.headers:
                 self.headers[hdrs.CONTENT_LENGTH] = str(len(self.body))
 
-    def update_auth(self, auth: Optional[BasicAuth]) -> None:
+    def update_auth(self, auth: Optional[BasicAuth], trust_env: bool = False) -> None:
         """Set basic auth."""
         if auth is None:
             auth = self.auth
         if auth is None:
+            if trust_env:
+                # If no auth is specified, we read from netrc.
+
+                netrc_obj = netrc_from_env()
+                if netrc_obj:
+                    auth = basicauth_from_netrc(netrc_obj, self.url.host)
+                    if auth:
+                        self.headers[hdrs.AUTHORIZATION] = auth.encode()
+
             return
 
         if not isinstance(auth, helpers.BasicAuth):

aiohttp/helpers.py

@@ -41,7 +41,6 @@
     Type,
     TypeVar,
     Union,
-    cast,
     overload,
 )
 from urllib.parse import quote
@@ -244,6 +243,31 @@ class ProxyInfo:
     proxy_auth: Optional[BasicAuth]
 
 
+def basicauth_from_netrc(netrc_obj: netrc.netrc, host: str) -> Optional[BasicAuth]:
+    auth_from_netrc = netrc_obj.authenticators(host)
+    if auth_from_netrc is not None:
+        login, account, password = auth_from_netrc
+        if not login:
+            # login is provided, we just use it as username.
+            # If login and account are both provided, only login is used
+            username = login
+        elif account:
+            # login is not provided, but account is
+            username = account
+        else:
+            # neither login nore account are provided, we use blank username
+            # this matches python 3.11 behavior
+            username = ""
+
+        if password is None:
+            # Password is not provided, we use blank string.
+            # this matches python 3.11 behavior
+            password = ""
+
+        auth = BasicAuth(username, password)
+        return auth
+
+
 def proxies_from_env() -> Dict[str, ProxyInfo]:
     proxy_urls = {
         k: URL(v)
@@ -261,16 +285,8 @@ def proxies_from_env() -> Dict[str, ProxyInfo]:
             )
             continue
         if netrc_obj and auth is None:
-            auth_from_netrc = None
             if proxy.host is not None:
-                auth_from_netrc = netrc_obj.authenticators(proxy.host)
-            if auth_from_netrc is not None:
-                # auth_from_netrc is a (`user`, `account`, `password`) tuple,
-                # `user` and `account` both can be username,
-                # if `user` is None, use `account`
-                *logins, password = auth_from_netrc
-                login = logins[0] if logins[0] else logins[-1]
-                auth = BasicAuth(cast(str, login), cast(str, password))
+                auth = basicauth_from_netrc(netrc_obj, proxy.host)
         ret[proto] = ProxyInfo(proxy, auth)
     return ret