Remove the 'password_hash' from the Users Admin API endpoint response dictionary (#11576)

5 files changed, 86 insertions, 43 deletions

diff --git a/changelog.d/11576.feature b/changelog.d/11576.feature
new file mode 100644
index 0000000000..5be836ae02
--- /dev/null
+++ b/changelog.d/11576.feature
@@ -0,0 +1 @@
+Remove the `"password_hash"` field from the response dictionaries of the [Users Admin API](https://matrix-org.github.io/synapse/latest/admin_api/user_admin_api.html).
\ No newline at end of file
diff --git a/docs/admin_api/user_admin_api.md b/docs/admin_api/user_admin_api.md
index 74933d2fcf..c514cadb9d 100644
--- a/docs/admin_api/user_admin_api.md
+++ b/docs/admin_api/user_admin_api.md
@@ -15,9 +15,10 @@ server admin: [Admin API](../usage/administration/admin_api)
 
 It returns a JSON body like the following:
 
-```json
+```jsonc
 {
-    "displayname": "User",
+    "name": "@user:example.com",
+    "displayname": "User", // can be null if not set
     "threepids": [
         {
             "medium": "email",
@@ -32,11 +33,11 @@ It returns a JSON body like the following:
             "validated_at": 1586458409743
         }
     ],
-    "avatar_url": "<avatar_url>",
+    "avatar_url": "<avatar_url>",  // can be null if not set
+    "is_guest": 0,
     "admin": 0,
     "deactivated": 0,
     "shadow_banned": 0,
-    "password_hash": "$2b$12$p9B4GkqYdRTPGD",
     "creation_ts": 1560432506,
     "appservice_id": null,
     "consent_server_notice_sent": null,
diff --git a/synapse/handlers/admin.py b/synapse/handlers/admin.py
index 85157a138b..00ab5e79bf 100644
--- a/synapse/handlers/admin.py
+++ b/synapse/handlers/admin.py
@@ -55,21 +55,47 @@ class AdminHandler:
 
     async def get_user(self, user: UserID) -> Optional[JsonDict]:
         """Function to get user details"""
-        ret = await self.store.get_user_by_id(user.to_string())
-        if ret:
-            profile = await self.store.get_profileinfo(user.localpart)
-            threepids = await self.store.user_get_threepids(user.to_string())
-            external_ids = [
-                ({"auth_provider": auth_provider, "external_id": external_id})
-                for auth_provider, external_id in await self.store.get_external_ids_by_user(
-                    user.to_string()
-                )
-            ]
-            ret["displayname"] = profile.display_name
-            ret["avatar_url"] = profile.avatar_url
-            ret["threepids"] = threepids
-            ret["external_ids"] = external_ids
-        return ret
+        user_info_dict = await self.store.get_user_by_id(user.to_string())
+        if user_info_dict is None:
+            return None
+
+        # Restrict returned information to a known set of fields. This prevents additional
+        # fields added to get_user_by_id from modifying Synapse's external API surface.
+        user_info_to_return = {
+            "name",
+            "admin",
+            "deactivated",
+            "shadow_banned",
+            "creation_ts",
+            "appservice_id",
+            "consent_server_notice_sent",
+            "consent_version",
+            "user_type",
+            "is_guest",
+        }
+
+        # Restrict returned keys to a known set.
+        user_info_dict = {
+            key: value
+            for key, value in user_info_dict.items()
+            if key in user_info_to_return
+        }
+
+        # Add additional user metadata
+        profile = await self.store.get_profileinfo(user.localpart)
+        threepids = await self.store.user_get_threepids(user.to_string())
+        external_ids = [
+            ({"auth_provider": auth_provider, "external_id": external_id})
+            for auth_provider, external_id in await self.store.get_external_ids_by_user(
+                user.to_string()
+            )
+        ]
+        user_info_dict["displayname"] = profile.display_name
+        user_info_dict["avatar_url"] = profile.avatar_url
+        user_info_dict["threepids"] = threepids
+        user_info_dict["external_ids"] = external_ids
+
+        return user_info_dict
 
     async def export_user_data(self, user_id: str, writer: "ExfiltrationWriter") -> Any:
         """Write all data we have on the user to the given writer.
diff --git a/synapse/rest/admin/users.py b/synapse/rest/admin/users.py
index 78e795c347..c2617ee30c 100644
--- a/synapse/rest/admin/users.py
+++ b/synapse/rest/admin/users.py
@@ -173,12 +173,11 @@ class UserRestServletV2(RestServlet):
         if not self.hs.is_mine(target_user):
             raise SynapseError(HTTPStatus.BAD_REQUEST, "Can only look up local users")
 
-        ret = await self.admin_handler.get_user(target_user)
-
-        if not ret:
+        user_info_dict = await self.admin_handler.get_user(target_user)
+        if not user_info_dict:
             raise NotFoundError("User not found")
 
-        return HTTPStatus.OK, ret
+        return HTTPStatus.OK, user_info_dict
 
     async def on_PUT(
         self, request: SynapseRequest, user_id: str
@@ -399,10 +398,10 @@ class UserRestServletV2(RestServlet):
                     target_user, requester, body["avatar_url"], True
                 )
 
-            user = await self.admin_handler.get_user(target_user)
-            assert user is not None
+            user_info_dict = await self.admin_handler.get_user(target_user)
+            assert user_info_dict is not None
 
-            return 201, user
+            return HTTPStatus.CREATED, user_info_dict
 
 
 class UserRegisterServlet(RestServlet):
diff --git a/tests/rest/admin/test_user.py b/tests/rest/admin/test_user.py
index e0b9fe8e91..9711405735 100644
--- a/tests/rest/admin/test_user.py
+++ b/tests/rest/admin/test_user.py
@@ -1181,6 +1181,7 @@ class UserRestTestCase(unittest.HomeserverTestCase):
                 self.other_user, device_id=None, valid_until_ms=None
             )
         )
+
         self.url_prefix = "/_synapse/admin/v2/users/%s"
         self.url_other_user = self.url_prefix % self.other_user
 
@@ -1188,7 +1189,7 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         """
         If the user is not a server admin, an error is returned.
         """
-        url = "/_synapse/admin/v2/users/@bob:test"
+        url = self.url_prefix % "@bob:test"
 
         channel = self.make_request(
             "GET",
@@ -1216,7 +1217,7 @@ class UserRestTestCase(unittest.HomeserverTestCase):
 
         channel = self.make_request(
             "GET",
-            "/_synapse/admin/v2/users/@unknown_person:test",
+            self.url_prefix % "@unknown_person:test",
             access_token=self.admin_user_tok,
         )
 
@@ -1337,7 +1338,7 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         """
         Check that a new admin user is created successfully.
         """
-        url = "/_synapse/admin/v2/users/@bob:test"
+        url = self.url_prefix % "@bob:test"
 
         # Create user (server admin)
         body = {
@@ -1386,7 +1387,7 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         """
         Check that a new regular user is created successfully.
         """
-        url = "/_synapse/admin/v2/users/@bob:test"
+        url = self.url_prefix % "@bob:test"
 
         # Create user
         body = {
@@ -1478,7 +1479,7 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         )
 
         # Register new user with admin API
-        url = "/_synapse/admin/v2/users/@bob:test"
+        url = self.url_prefix % "@bob:test"
 
         # Create user
         channel = self.make_request(
@@ -1515,7 +1516,7 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         )
 
         # Register new user with admin API
-        url = "/_synapse/admin/v2/users/@bob:test"
+        url = self.url_prefix % "@bob:test"
 
         # Create user
         channel = self.make_request(
@@ -1545,7 +1546,7 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         Check that a new regular user is created successfully and
         got an email pusher.
         """
-        url = "/_synapse/admin/v2/users/@bob:test"
+        url = self.url_prefix % "@bob:test"
 
         # Create user
         body = {
@@ -1588,7 +1589,7 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         Check that a new regular user is created successfully and
         got not an email pusher.
         """
-        url = "/_synapse/admin/v2/users/@bob:test"
+        url = self.url_prefix % "@bob:test"
 
         # Create user
         body = {
@@ -2085,10 +2086,13 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         self.assertEqual(HTTPStatus.OK, channel.code, msg=channel.json_body)
         self.assertEqual("@user:test", channel.json_body["name"])
         self.assertTrue(channel.json_body["deactivated"])
-        self.assertIsNone(channel.json_body["password_hash"])
         self.assertEqual(0, len(channel.json_body["threepids"]))
         self.assertEqual("mxc://servername/mediaid", channel.json_body["avatar_url"])
         self.assertEqual("User", channel.json_body["displayname"])
+
+        # This key was removed intentionally. Ensure it is not accidentally re-included.
+        self.assertNotIn("password_hash", channel.json_body)
+
         # the user is deactivated, the threepid will be deleted
 
         # Get user
@@ -2101,11 +2105,13 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         self.assertEqual(HTTPStatus.OK, channel.code, msg=channel.json_body)
         self.assertEqual("@user:test", channel.json_body["name"])
         self.assertTrue(channel.json_body["deactivated"])
-        self.assertIsNone(channel.json_body["password_hash"])
         self.assertEqual(0, len(channel.json_body["threepids"]))
         self.assertEqual("mxc://servername/mediaid", channel.json_body["avatar_url"])
         self.assertEqual("User", channel.json_body["displayname"])
 
+        # This key was removed intentionally. Ensure it is not accidentally re-included.
+        self.assertNotIn("password_hash", channel.json_body)
+
     @override_config({"user_directory": {"enabled": True, "search_all_users": True}})
     def test_change_name_deactivate_user_user_directory(self):
         """
@@ -2177,9 +2183,11 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         self.assertEqual(HTTPStatus.OK, channel.code, msg=channel.json_body)
         self.assertEqual("@user:test", channel.json_body["name"])
         self.assertFalse(channel.json_body["deactivated"])
-        self.assertIsNotNone(channel.json_body["password_hash"])
         self._is_erased("@user:test", False)
 
+        # This key was removed intentionally. Ensure it is not accidentally re-included.
+        self.assertNotIn("password_hash", channel.json_body)
+
     @override_config({"password_config": {"localdb_enabled": False}})
     def test_reactivate_user_localdb_disabled(self):
         """
@@ -2209,9 +2217,11 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         self.assertEqual(HTTPStatus.OK, channel.code, msg=channel.json_body)
         self.assertEqual("@user:test", channel.json_body["name"])
         self.assertFalse(channel.json_body["deactivated"])
-        self.assertIsNone(channel.json_body["password_hash"])
         self._is_erased("@user:test", False)
 
+        # This key was removed intentionally. Ensure it is not accidentally re-included.
+        self.assertNotIn("password_hash", channel.json_body)
+
     @override_config({"password_config": {"enabled": False}})
     def test_reactivate_user_password_disabled(self):
         """
@@ -2241,9 +2251,11 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         self.assertEqual(HTTPStatus.OK, channel.code, msg=channel.json_body)
         self.assertEqual("@user:test", channel.json_body["name"])
         self.assertFalse(channel.json_body["deactivated"])
-        self.assertIsNone(channel.json_body["password_hash"])
         self._is_erased("@user:test", False)
 
+        # This key was removed intentionally. Ensure it is not accidentally re-included.
+        self.assertNotIn("password_hash", channel.json_body)
+
     def test_set_user_as_admin(self):
         """
         Test setting the admin flag on a user.
@@ -2328,7 +2340,7 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         Ensure an account can't accidentally be deactivated by using a str value
         for the deactivated body parameter
         """
-        url = "/_synapse/admin/v2/users/@bob:test"
+        url = self.url_prefix % "@bob:test"
 
         # Create user
         channel = self.make_request(
@@ -2392,18 +2404,20 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         # Deactivate the user.
         channel = self.make_request(
             "PUT",
-            "/_synapse/admin/v2/users/%s" % urllib.parse.quote(user_id),
+            self.url_prefix % urllib.parse.quote(user_id),
             access_token=self.admin_user_tok,
             content={"deactivated": True},
         )
         self.assertEqual(HTTPStatus.OK, channel.code, msg=channel.json_body)
         self.assertTrue(channel.json_body["deactivated"])
-        self.assertIsNone(channel.json_body["password_hash"])
         self._is_erased(user_id, False)
         d = self.store.mark_user_erased(user_id)
         self.assertIsNone(self.get_success(d))
         self._is_erased(user_id, True)
 
+        # This key was removed intentionally. Ensure it is not accidentally re-included.
+        self.assertNotIn("password_hash", channel.json_body)
+
     def _check_fields(self, content: JsonDict):
         """Checks that the expected user attributes are present in content
 
@@ -2416,13 +2430,15 @@ class UserRestTestCase(unittest.HomeserverTestCase):
         self.assertIn("admin", content)
         self.assertIn("deactivated", content)
         self.assertIn("shadow_banned", content)
-        self.assertIn("password_hash", content)
         self.assertIn("creation_ts", content)
         self.assertIn("appservice_id", content)
         self.assertIn("consent_server_notice_sent", content)
         self.assertIn("consent_version", content)
         self.assertIn("external_ids", content)
 
+        # This key was removed intentionally. Ensure it is not accidentally re-included.
+        self.assertNotIn("password_hash", content)
+
 
 class UserMembershipRestTestCase(unittest.HomeserverTestCase):