Add RFC 6750 Bearer Token Auth

Author: loechel

httpx/__init__.py

@@ -38,6 +38,7 @@ def main() -> None:  # type: ignore
     "Auth",
     "BaseTransport",
     "BasicAuth",
+    "BearerTokenAuth",
     "ByteStream",
     "Client",
     "CloseError",

httpx/_auth.py

@@ -16,7 +16,7 @@
     from hashlib import _Hash
 
 
-__all__ = ["Auth", "BasicAuth", "DigestAuth", "NetRCAuth"]
+__all__ = ["Auth", "BasicAuth", "BearerTokenAuth", "DigestAuth", "NetRCAuth"]
 
 
 class Auth:
@@ -142,6 +142,23 @@ def _build_auth_header(self, username: str | bytes, password: str | bytes) -> st
         return f"Basic {token}"
 
 
+class BearerTokenAuth(Auth):
+    """
+    Allows the 'auth' argument to be passed as a bearer token string,
+    and uses HTTP Bearer authentication (RFC 6750).
+    """
+
+    def __init__(self, bearer_token: str | bytes) -> None:
+        self._auth_header = self._build_auth_header(bearer_token)
+
+    def auth_flow(self, request: Request) -> typing.Generator[Request, Response, None]:
+        request.headers["Authorization"] = self._auth_header
+        yield request
+
+    def _build_auth_header(self, bearer_token: str | bytes) -> str:
+        return f"Bearer {to_bytes(bearer_token).decode()}"
+
+
 class NetRCAuth(Auth):
     """
     Use a 'netrc' file to lookup basic auth credentials based on the url host.

tests/test_auth.py

@@ -26,6 +26,21 @@ def test_basic_auth():
         flow.send(response)
 
 
+def test_bearer_token_auth():
+    auth = httpx.BearerTokenAuth(bearer_token="my_token")
+    request = httpx.Request("GET", "https://www.example.com")
+
+    # The initial request should include a bearer token auth header.
+    flow = auth.sync_auth_flow(request)
+    request = next(flow)
+    assert request.headers["Authorization"].startswith("Bearer ")
+
+    # No other requests are made.
+    response = httpx.Response(content=b"Hello, world!", status_code=200)
+    with pytest.raises(StopIteration):
+        flow.send(response)
+
+
 def test_digest_auth_with_200():
     auth = httpx.DigestAuth(username="user", password="pass")
     request = httpx.Request("GET", "https://www.example.com")