From 79eb6c0cdc15ccb5083368c923653862a4d2d23a Mon Sep 17 00:00:00 2001 From: Will Hunt Date: Fri, 29 Sep 2023 12:19:38 +0100 Subject: [PATCH] Support rendering some media downloads as inline (#15988) Use an `inline` Content-Disposition header when the media is "safe" to display inline (some known text, image, video, audio formats). --- changelog.d/15988.feature | 1 + synapse/media/_base.py | 42 +++++++++++++++++++++++++++++-- tests/media/test_base.py | 29 ++++++++++++++++++++- tests/media/test_media_storage.py | 40 ++++++++++++++++++++++++++--- 4 files changed, 106 insertions(+), 6 deletions(-) create mode 100644 changelog.d/15988.feature diff --git a/changelog.d/15988.feature b/changelog.d/15988.feature new file mode 100644 index 000000000..dee8fa597 --- /dev/null +++ b/changelog.d/15988.feature @@ -0,0 +1 @@ +Render plain, CSS, CSV, JSON and common image formats media content in the browser (inline) when requested through the /download endpoint. \ No newline at end of file diff --git a/synapse/media/_base.py b/synapse/media/_base.py index 20cb8b901..80c448de2 100644 --- a/synapse/media/_base.py +++ b/synapse/media/_base.py @@ -50,6 +50,39 @@ TEXT_CONTENT_TYPES = [ "text/xml", ] +# A list of all content types that are "safe" to be rendered inline in a browser. +INLINE_CONTENT_TYPES = [ + "text/css", + "text/plain", + "text/csv", + "application/json", + "application/ld+json", + # We allow some media files deemed as safe, which comes from the matrix-react-sdk. + # https://github.com/matrix-org/matrix-react-sdk/blob/a70fcfd0bcf7f8c85986da18001ea11597989a7c/src/utils/blobs.ts#L51 + # SVGs are *intentionally* omitted. + "image/jpeg", + "image/gif", + "image/png", + "image/apng", + "image/webp", + "image/avif", + "video/mp4", + "video/webm", + "video/ogg", + "video/quicktime", + "audio/mp4", + "audio/webm", + "audio/aac", + "audio/mpeg", + "audio/ogg", + "audio/wave", + "audio/wav", + "audio/x-wav", + "audio/x-pn-wav", + "audio/flac", + "audio/x-flac", +] + def parse_media_id(request: Request) -> Tuple[str, str, Optional[str]]: """Parses the server name, media ID and optional file name from the request URI @@ -153,8 +186,13 @@ def add_file_headers( request.setHeader(b"Content-Type", content_type.encode("UTF-8")) - # Use a Content-Disposition of attachment to force download of media. - disposition = "attachment" + # A strict subset of content types is allowed to be inlined so that they may + # be viewed directly in a browser. Other file types are forced to be downloads. + if media_type.lower() in INLINE_CONTENT_TYPES: + disposition = "inline" + else: + disposition = "attachment" + if upload_name: # RFC6266 section 4.1 [1] defines both `filename` and `filename*`. # diff --git a/tests/media/test_base.py b/tests/media/test_base.py index 4728c8096..119d7ba66 100644 --- a/tests/media/test_base.py +++ b/tests/media/test_base.py @@ -12,7 +12,9 @@ # See the License for the specific language governing permissions and # limitations under the License. -from synapse.media._base import get_filename_from_headers +from unittest.mock import Mock + +from synapse.media._base import add_file_headers, get_filename_from_headers from tests import unittest @@ -36,3 +38,28 @@ class GetFileNameFromHeadersTests(unittest.TestCase): expected, f"expected output for {hdr!r} to be {expected} but was {res}", ) + + +class AddFileHeadersTests(unittest.TestCase): + TEST_CASES = { + "text/plain": b"inline; filename=file.name", + "text/csv": b"inline; filename=file.name", + "image/png": b"inline; filename=file.name", + "text/html": b"attachment; filename=file.name", + "any/thing": b"attachment; filename=file.name", + } + + def test_content_disposition(self) -> None: + for media_type, expected in self.TEST_CASES.items(): + request = Mock() + add_file_headers(request, media_type, 0, "file.name") + request.setHeader.assert_any_call(b"Content-Disposition", expected) + + def test_no_filename(self) -> None: + request = Mock() + add_file_headers(request, "text/plain", 0, None) + request.setHeader.assert_any_call(b"Content-Disposition", b"inline") + + request.reset_mock() + add_file_headers(request, "text/html", 0, None) + request.setHeader.assert_any_call(b"Content-Disposition", b"attachment") diff --git a/tests/media/test_media_storage.py b/tests/media/test_media_storage.py index ea0051dde..04fc7bdce 100644 --- a/tests/media/test_media_storage.py +++ b/tests/media/test_media_storage.py @@ -129,6 +129,8 @@ class _TestImage: a 404/400 is expected. unable_to_thumbnail: True if we expect the thumbnailing to fail (400), or False if the thumbnailing should succeed or a normal 404 is expected. + is_inline: True if we expect the file to be served using an inline + Content-Disposition or False if we expect an attachment. """ data: bytes @@ -138,6 +140,7 @@ class _TestImage: expected_scaled: Optional[bytes] = None expected_found: bool = True unable_to_thumbnail: bool = False + is_inline: bool = True @parameterized_class( @@ -198,6 +201,25 @@ class _TestImage: unable_to_thumbnail=True, ), ), + # An SVG. + ( + _TestImage( + b""" + + + + +""", + b"image/svg", + b".svg", + expected_found=False, + unable_to_thumbnail=True, + is_inline=False, + ), + ), ], ) class MediaRepoTests(unittest.HomeserverTestCase): @@ -339,7 +361,11 @@ class MediaRepoTests(unittest.HomeserverTestCase): ) self.assertEqual( headers.getRawHeaders(b"Content-Disposition"), - [b"attachment; filename=out" + self.test_image.extension], + [ + (b"inline" if self.test_image.is_inline else b"attachment") + + b"; filename=out" + + self.test_image.extension + ], ) def test_disposition_filenamestar_utf8escaped(self) -> None: @@ -359,7 +385,12 @@ class MediaRepoTests(unittest.HomeserverTestCase): ) self.assertEqual( headers.getRawHeaders(b"Content-Disposition"), - [b"attachment; filename*=utf-8''" + filename + self.test_image.extension], + [ + (b"inline" if self.test_image.is_inline else b"attachment") + + b"; filename*=utf-8''" + + filename + + self.test_image.extension + ], ) def test_disposition_none(self) -> None: @@ -373,7 +404,10 @@ class MediaRepoTests(unittest.HomeserverTestCase): self.assertEqual( headers.getRawHeaders(b"Content-Type"), [self.test_image.content_type] ) - self.assertEqual(headers.getRawHeaders(b"Content-Disposition"), [b"attachment"]) + self.assertEqual( + headers.getRawHeaders(b"Content-Disposition"), + [b"inline" if self.test_image.is_inline else b"attachment"], + ) def test_thumbnail_crop(self) -> None: """Test that a cropped remote thumbnail is available."""