Restrict OAuth proxy redirect URLs

src/enapter_mcp_server/cli/serve_command.py

@@ -31,6 +31,9 @@
 ENAPTER_OAUTH_PROXY_REQUIRED_SCOPES = os.getenv(
     "ENAPTER_OAUTH_PROXY_REQUIRED_SCOPES", "openid,public"
 )
+ENAPTER_OAUTH_PROXY_ALLOWED_REDIRECT_URLS = os.getenv(
+    "ENAPTER_OAUTH_PROXY_ALLOWED_REDIRECT_URLS", ""
+)
 ENAPTER_OAUTH_PROXY_CLIENT_ID = os.getenv("ENAPTER_OAUTH_PROXY_CLIENT_ID")
 ENAPTER_OAUTH_PROXY_CLIENT_SECRET = os.getenv("ENAPTER_OAUTH_PROXY_CLIENT_SECRET")
 ENAPTER_OAUTH_PROXY_JWT_STORE_URL = os.getenv(
@@ -99,6 +102,11 @@ def register(parent: Subparsers) -> None:
             default=ENAPTER_OAUTH_PROXY_REQUIRED_SCOPES,
             help="Comma-separated list of required scopes for OAuth proxy",
         )
+        parser.add_argument(
+            "--oauth-proxy-allowed-redirect-urls",
+            default=ENAPTER_OAUTH_PROXY_ALLOWED_REDIRECT_URLS,
+            help="Comma-separated list of allowed redirect URLs for OAuth proxy",
+        )
         parser.add_argument(
             "--oauth-proxy-client-id",
             default=ENAPTER_OAUTH_PROXY_CLIENT_ID,
@@ -132,6 +140,11 @@ async def run(args: argparse.Namespace) -> None:
                 for scope in args.oauth_proxy_required_scopes.split(",")
                 if scope.strip()
             ]
+            allowed_redirect_urls = [
+                url.strip()
+                for url in args.oauth_proxy_allowed_redirect_urls.split(",")
+                if url.strip()
+            ]
             oauth_proxy_config = mcp.OAuthProxyConfig(
                 introspection_endpoint_url=args.oauth_proxy_introspection_url,
                 authorization_endpoint_url=args.oauth_proxy_authorization_url,
@@ -142,6 +155,9 @@ async def run(args: argparse.Namespace) -> None:
                 required_scopes=required_scopes,
                 client_id=args.oauth_proxy_client_id,
                 client_secret=args.oauth_proxy_client_secret,
+                allowed_redirect_urls=(
+                    allowed_redirect_urls if allowed_redirect_urls else None
+                ),
                 jwt_store_url=args.oauth_proxy_jwt_store_url,
                 jwt_signing_key=args.oauth_proxy_jwt_signing_key,
             )

src/enapter_mcp_server/mcp/oauth_proxy_config.py

@@ -13,5 +13,6 @@ class OAuthProxyConfig:
     required_scopes: list[str]
     client_id: str
     client_secret: str
+    allowed_redirect_urls: list[str] | None = None
     jwt_store_url: str | None = None
     jwt_signing_key: str | None = None

src/enapter_mcp_server/mcp/server.py

@@ -86,6 +86,7 @@ def _select_auth_provider(self) -> fastmcp.server.auth.AuthProvider | None:
             token_verifier=token_verifier,
             base_url=self._config.oauth_proxy.protected_resource_url,
             forward_pkce=self._config.oauth_proxy.forward_pkce,
+            allowed_client_redirect_uris=self._config.oauth_proxy.allowed_redirect_urls,
             client_storage=jwt_store,
             jwt_signing_key=self._config.oauth_proxy.jwt_signing_key,
         )

tests/unit/cli/test_serve_command.py

@@ -0,0 +1,82 @@
+import argparse
+import asyncio
+from unittest.mock import patch
+
+import pytest
+
+from enapter_mcp_server.cli.serve_command import ServeCommand
+
+
+class TestServeCommand:
+    @pytest.mark.asyncio
+    async def test_run_parses_allowed_redirect_urls(self):
+        args = argparse.Namespace(
+            address="127.0.0.1:8080",
+            enapter_http_api_url="https://api.example.com",
+            logo_url="https://logo.example.com",
+            oauth_proxy_enabled="1",
+            oauth_proxy_introspection_url="https://sso.example.com/introspect",
+            oauth_proxy_authorization_url="https://sso.example.com/authorize",
+            oauth_proxy_token_url="https://sso.example.com/token",
+            oauth_proxy_user_info_url="https://sso.example.com/me",
+            oauth_proxy_protected_resource_url="https://mcp.example.com",
+            oauth_proxy_forward_pkce="1",
+            oauth_proxy_required_scopes="openid,profile",
+            oauth_proxy_allowed_redirect_urls="http://localhost:3000,http://localhost:3001",
+            oauth_proxy_client_id="client_id",
+            oauth_proxy_client_secret="client_secret",
+            oauth_proxy_jwt_store_url="memory://",
+            oauth_proxy_jwt_signing_key="signing_key",
+            verbose=False,
+        )
+
+        with patch("enapter_mcp_server.mcp.Server", autospec=True) as mock_server:
+            # We need to mock the async context manager
+            mock_server_instance = mock_server.return_value
+            mock_server_instance.__aenter__.return_value = mock_server_instance
+
+            # ServeCommand.run has an infinite wait, so we need to break it
+            with patch("asyncio.Event.wait", side_effect=asyncio.CancelledError):
+                with pytest.raises(asyncio.CancelledError):
+                    await ServeCommand.run(args)
+
+            mock_server.assert_called_once()
+            config = mock_server.call_args[1]["config"]
+            assert config.oauth_proxy is not None
+            assert config.oauth_proxy.allowed_redirect_urls == [
+                "http://localhost:3000",
+                "http://localhost:3001",
+            ]
+
+    @pytest.mark.asyncio
+    async def test_run_handles_empty_allowed_redirect_urls(self):
+        args = argparse.Namespace(
+            address="127.0.0.1:8080",
+            enapter_http_api_url="https://api.example.com",
+            logo_url="https://logo.example.com",
+            oauth_proxy_enabled="1",
+            oauth_proxy_introspection_url="https://sso.example.com/introspect",
+            oauth_proxy_authorization_url="https://sso.example.com/authorize",
+            oauth_proxy_token_url="https://sso.example.com/token",
+            oauth_proxy_user_info_url="https://sso.example.com/me",
+            oauth_proxy_protected_resource_url="https://mcp.example.com",
+            oauth_proxy_forward_pkce="1",
+            oauth_proxy_required_scopes="openid,profile",
+            oauth_proxy_allowed_redirect_urls="",
+            oauth_proxy_client_id="client_id",
+            oauth_proxy_client_secret="client_secret",
+            oauth_proxy_jwt_store_url="memory://",
+            oauth_proxy_jwt_signing_key="signing_key",
+            verbose=False,
+        )
+
+        with patch("enapter_mcp_server.mcp.Server", autospec=True) as mock_server:
+            mock_server_instance = mock_server.return_value
+            mock_server_instance.__aenter__.return_value = mock_server_instance
+
+            with patch("asyncio.Event.wait", side_effect=asyncio.CancelledError):
+                with pytest.raises(asyncio.CancelledError):
+                    await ServeCommand.run(args)
+
+            config = mock_server.call_args[1]["config"]
+            assert config.oauth_proxy.allowed_redirect_urls is None