Add basic SAML tests for mapping users. (#8800)

tests/handlers/test_saml.py

@@ -0,0 +1,136 @@
+#  Copyright 2020 The Matrix.org Foundation C.I.C.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+
+import attr
+
+from synapse.handlers.sso import MappingException
+
+from tests.unittest import HomeserverTestCase
+
+# These are a few constants that are used as config parameters in the tests.
+BASE_URL = "https://synapse/"
+
+
+@attr.s
+class FakeAuthnResponse:
+    ava = attr.ib(type=dict)
+
+
+class TestMappingProvider:
+    def __init__(self, config, module):
+        pass
+
+    @staticmethod
+    def parse_config(config):
+        return
+
+    @staticmethod
+    def get_saml_attributes(config):
+        return {"uid"}, {"displayName"}
+
+    def get_remote_user_id(self, saml_response, client_redirect_url):
+        return saml_response.ava["uid"]
+
+    def saml_response_to_user_attributes(
+        self, saml_response, failures, client_redirect_url
+    ):
+        localpart = saml_response.ava["username"] + (str(failures) if failures else "")
+        return {"mxid_localpart": localpart, "displayname": None}
+
+
+class SamlHandlerTestCase(HomeserverTestCase):
+    def default_config(self):
+        config = super().default_config()
+        config["public_baseurl"] = BASE_URL
+        saml_config = {
+            "sp_config": {"metadata": {}},
+            # Disable grandfathering.
+            "grandfathered_mxid_source_attribute": None,
+            "user_mapping_provider": {"module": __name__ + ".TestMappingProvider"},
+        }
+        config["saml2_config"] = saml_config
+
+        return config
+
+    def make_homeserver(self, reactor, clock):
+        hs = self.setup_test_homeserver()
+
+        self.handler = hs.get_saml_handler()
+
+        # Reduce the number of attempts when generating MXIDs.
+        sso_handler = hs.get_sso_handler()
+        sso_handler._MAP_USERNAME_RETRIES = 3
+
+        return hs
+
+    def test_map_saml_response_to_user(self):
+        """Ensure that mapping the SAML response returned from a provider to an MXID works properly."""
+        saml_response = FakeAuthnResponse({"uid": "test_user", "username": "test_user"})
+        # The redirect_url doesn't matter with the default user mapping provider.
+        redirect_url = ""
+        mxid = self.get_success(
+            self.handler._map_saml_response_to_user(
+                saml_response, redirect_url, "user-agent", "10.10.10.10"
+            )
+        )
+        self.assertEqual(mxid, "@test_user:test")
+
+    def test_map_saml_response_to_invalid_localpart(self):
+        """If the mapping provider generates an invalid localpart it should be rejected."""
+        saml_response = FakeAuthnResponse({"uid": "test", "username": "föö"})
+        redirect_url = ""
+        e = self.get_failure(
+            self.handler._map_saml_response_to_user(
+                saml_response, redirect_url, "user-agent", "10.10.10.10"
+            ),
+            MappingException,
+        )
+        self.assertEqual(str(e.value), "localpart is invalid: föö")
+
+    def test_map_saml_response_to_user_retries(self):
+        """The mapping provider can retry generating an MXID if the MXID is already in use."""
+        store = self.hs.get_datastore()
+        self.get_success(
+            store.register_user(user_id="@test_user:test", password_hash=None)
+        )
+        saml_response = FakeAuthnResponse({"uid": "test", "username": "test_user"})
+        redirect_url = ""
+        mxid = self.get_success(
+            self.handler._map_saml_response_to_user(
+                saml_response, redirect_url, "user-agent", "10.10.10.10"
+            )
+        )
+        # test_user is already taken, so test_user1 gets registered instead.
+        self.assertEqual(mxid, "@test_user1:test")
+
+        # Register all of the potential mxids for a particular SAML username.
+        self.get_success(
+            store.register_user(user_id="@tester:test", password_hash=None)
+        )
+        for i in range(1, 3):
+            self.get_success(
+                store.register_user(user_id="@tester%d:test" % i, password_hash=None)
+            )
+
+        # Now attempt to map to a username, this will fail since all potential usernames are taken.
+        saml_response = FakeAuthnResponse({"uid": "tester", "username": "tester"})
+        e = self.get_failure(
+            self.handler._map_saml_response_to_user(
+                saml_response, redirect_url, "user-agent", "10.10.10.10"
+            ),
+            MappingException,
+        )
+        self.assertEqual(
+            str(e.value), "Unable to generate a Matrix ID from the SSO response"
+        )