Support MSC3916 by adding a federation `/download` endpoint (#17172)

2 files changed, 246 insertions, 2 deletions

diff --git a/tests/federation/test_federation_media.py b/tests/federation/test_federation_media.py
new file mode 100644
index 0000000000..1c89d19e99
--- /dev/null
+++ b/tests/federation/test_federation_media.py
@@ -0,0 +1,234 @@
+#
+# This file is licensed under the Affero General Public License (AGPL) version 3.
+#
+# Copyright (C) 2024 New Vector, Ltd
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# See the GNU Affero General Public License for more details:
+# <https://www.gnu.org/licenses/agpl-3.0.html>.
+#
+# Originally licensed under the Apache License, Version 2.0:
+# <http://www.apache.org/licenses/LICENSE-2.0>.
+#
+# [This file includes modifications made by New Vector Limited]
+#
+#
+import io
+import os
+import shutil
+import tempfile
+from typing import Optional
+
+from twisted.test.proto_helpers import MemoryReactor
+
+from synapse.media._base import FileInfo, Responder
+from synapse.media.filepath import MediaFilePaths
+from synapse.media.media_storage import MediaStorage
+from synapse.media.storage_provider import (
+    FileStorageProviderBackend,
+    StorageProviderWrapper,
+)
+from synapse.server import HomeServer
+from synapse.storage.databases.main.media_repository import LocalMedia
+from synapse.types import JsonDict, UserID
+from synapse.util import Clock
+
+from tests import unittest
+from tests.test_utils import SMALL_PNG
+from tests.unittest import override_config
+
+
+class FederationUnstableMediaDownloadsTest(unittest.FederatingHomeserverTestCase):
+
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
+        super().prepare(reactor, clock, hs)
+        self.test_dir = tempfile.mkdtemp(prefix="synapse-tests-")
+        self.addCleanup(shutil.rmtree, self.test_dir)
+        self.primary_base_path = os.path.join(self.test_dir, "primary")
+        self.secondary_base_path = os.path.join(self.test_dir, "secondary")
+
+        hs.config.media.media_store_path = self.primary_base_path
+
+        storage_providers = [
+            StorageProviderWrapper(
+                FileStorageProviderBackend(hs, self.secondary_base_path),
+                store_local=True,
+                store_remote=False,
+                store_synchronous=True,
+            )
+        ]
+
+        self.filepaths = MediaFilePaths(self.primary_base_path)
+        self.media_storage = MediaStorage(
+            hs, self.primary_base_path, self.filepaths, storage_providers
+        )
+        self.media_repo = hs.get_media_repository()
+
+    @override_config(
+        {"experimental_features": {"msc3916_authenticated_media_enabled": True}}
+    )
+    def test_file_download(self) -> None:
+        content = io.BytesIO(b"file_to_stream")
+        content_uri = self.get_success(
+            self.media_repo.create_content(
+                "text/plain",
+                "test_upload",
+                content,
+                46,
+                UserID.from_string("@user_id:whatever.org"),
+            )
+        )
+        # test with a text file
+        channel = self.make_signed_federation_request(
+            "GET",
+            f"/_matrix/federation/unstable/org.matrix.msc3916/media/download/{content_uri.media_id}",
+        )
+        self.pump()
+        self.assertEqual(200, channel.code)
+
+        content_type = channel.headers.getRawHeaders("content-type")
+        assert content_type is not None
+        assert "multipart/mixed" in content_type[0]
+        assert "boundary" in content_type[0]
+
+        # extract boundary
+        boundary = content_type[0].split("boundary=")[1]
+        # split on boundary and check that json field and expected value exist
+        stripped = channel.text_body.split("\r\n" + "--" + boundary)
+        # TODO: the json object expected will change once MSC3911 is implemented, currently
+        # {} is returned for all requests as a placeholder (per MSC3196)
+        found_json = any(
+            "\r\nContent-Type: application/json\r\n{}" in field for field in stripped
+        )
+        self.assertTrue(found_json)
+
+        # check that text file and expected value exist
+        found_file = any(
+            "\r\nContent-Type: text/plain\r\nfile_to_stream" in field
+            for field in stripped
+        )
+        self.assertTrue(found_file)
+
+        content = io.BytesIO(SMALL_PNG)
+        content_uri = self.get_success(
+            self.media_repo.create_content(
+                "image/png",
+                "test_png_upload",
+                content,
+                67,
+                UserID.from_string("@user_id:whatever.org"),
+            )
+        )
+        # test with an image file
+        channel = self.make_signed_federation_request(
+            "GET",
+            f"/_matrix/federation/unstable/org.matrix.msc3916/media/download/{content_uri.media_id}",
+        )
+        self.pump()
+        self.assertEqual(200, channel.code)
+
+        content_type = channel.headers.getRawHeaders("content-type")
+        assert content_type is not None
+        assert "multipart/mixed" in content_type[0]
+        assert "boundary" in content_type[0]
+
+        # extract boundary
+        boundary = content_type[0].split("boundary=")[1]
+        # split on boundary and check that json field and expected value exist
+        body = channel.result.get("body")
+        assert body is not None
+        stripped_bytes = body.split(b"\r\n" + b"--" + boundary.encode("utf-8"))
+        found_json = any(
+            b"\r\nContent-Type: application/json\r\n{}" in field
+            for field in stripped_bytes
+        )
+        self.assertTrue(found_json)
+
+        # check that png file exists and matches what was uploaded
+        found_file = any(SMALL_PNG in field for field in stripped_bytes)
+        self.assertTrue(found_file)
+
+    @override_config(
+        {"experimental_features": {"msc3916_authenticated_media_enabled": False}}
+    )
+    def test_disable_config(self) -> None:
+        content = io.BytesIO(b"file_to_stream")
+        content_uri = self.get_success(
+            self.media_repo.create_content(
+                "text/plain",
+                "test_upload",
+                content,
+                46,
+                UserID.from_string("@user_id:whatever.org"),
+            )
+        )
+        channel = self.make_signed_federation_request(
+            "GET",
+            f"/_matrix/federation/unstable/org.matrix.msc3916/media/download/{content_uri.media_id}",
+        )
+        self.pump()
+        self.assertEqual(404, channel.code)
+        self.assertEqual(channel.json_body.get("errcode"), "M_UNRECOGNIZED")
+
+
+class FakeFileStorageProviderBackend:
+    """
+    Fake storage provider stub with incompatible `fetch` signature for testing
+    """
+
+    def __init__(self, hs: "HomeServer", config: str):
+        self.hs = hs
+        self.cache_directory = hs.config.media.media_store_path
+        self.base_directory = config
+
+    def __str__(self) -> str:
+        return "FakeFileStorageProviderBackend[%s]" % (self.base_directory,)
+
+    async def fetch(
+        self, path: str, file_info: FileInfo, media_info: Optional[LocalMedia] = None
+    ) -> Optional[Responder]:
+        pass
+
+
+TEST_DIR = tempfile.mkdtemp(prefix="synapse-tests-")
+
+
+class FederationUnstableMediaEndpointCompatibilityTest(
+    unittest.FederatingHomeserverTestCase
+):
+
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
+        super().prepare(reactor, clock, hs)
+        self.test_dir = TEST_DIR
+        self.addCleanup(shutil.rmtree, self.test_dir)
+        self.media_repo = hs.get_media_repository()
+
+    def default_config(self) -> JsonDict:
+        config = super().default_config()
+        primary_base_path = os.path.join(TEST_DIR, "primary")
+        config["media_storage_providers"] = [
+            {
+                "module": "tests.federation.test_federation_media.FakeFileStorageProviderBackend",
+                "store_local": "True",
+                "store_remote": "False",
+                "store_synchronous": "False",
+                "config": {"directory": primary_base_path},
+            }
+        ]
+        return config
+
+    @override_config(
+        {"experimental_features": {"msc3916_authenticated_media_enabled": True}}
+    )
+    def test_incompatible_storage_provider_fails_to_load_endpoint(self) -> None:
+        channel = self.make_signed_federation_request(
+            "GET",
+            "/_matrix/federation/unstable/org.matrix.msc3916/media/download/xyz",
+        )
+        self.pump()
+        self.assertEqual(404, channel.code)
+        self.assertEqual(channel.json_body.get("errcode"), "M_UNRECOGNIZED")
diff --git a/tests/media/test_media_storage.py b/tests/media/test_media_storage.py
index 46d20ce775..47a89e9c66 100644
--- a/tests/media/test_media_storage.py
+++ b/tests/media/test_media_storage.py
@@ -49,7 +49,10 @@ from synapse.logging.context import make_deferred_yieldable
 from synapse.media._base import FileInfo, ThumbnailInfo
 from synapse.media.filepath import MediaFilePaths
 from synapse.media.media_storage import MediaStorage, ReadableFileWrapper
-from synapse.media.storage_provider import FileStorageProviderBackend
+from synapse.media.storage_provider import (
+    FileStorageProviderBackend,
+    StorageProviderWrapper,
+)
 from synapse.media.thumbnailer import ThumbnailProvider
 from synapse.module_api import ModuleApi
 from synapse.module_api.callbacks.spamchecker_callbacks import load_legacy_spam_checkers
@@ -78,7 +81,14 @@ class MediaStorageTests(unittest.HomeserverTestCase):
 
         hs.config.media.media_store_path = self.primary_base_path
 
-        storage_providers = [FileStorageProviderBackend(hs, self.secondary_base_path)]
+        storage_providers = [
+            StorageProviderWrapper(
+                FileStorageProviderBackend(hs, self.secondary_base_path),
+                store_local=True,
+                store_remote=False,
+                store_synchronous=True,
+            )
+        ]
 
         self.filepaths = MediaFilePaths(self.primary_base_path)
         self.media_storage = MediaStorage(