media: trust client Content-Type again

Signed-off-by: strawberry <strawberry@puppygock.gay>

src/api/client_server/media.rs

@@ -22,9 +22,7 @@
 	services,
 	utils::{
 		self,
-		content_disposition::{
-			content_disposition_type, make_content_disposition, make_content_type, sanitise_filename,
-		},
+		content_disposition::{content_disposition_type, make_content_disposition, sanitise_filename},
 	},
 	Error, Result, Ruma, RumaResponse,
 };
@@ -131,8 +129,6 @@ pub(crate) async fn create_content_route(
 		utils::random_string(MXC_LENGTH)
 	);
 
-	let content_type = Some(make_content_type(&body.file, &body.content_type).to_owned());
-
 	services()
 		.media
 		.create(
@@ -143,12 +139,12 @@ pub(crate) async fn create_content_route(
 				.map(|filename| {
 					format!(
 						"{}; filename={}",
-						content_disposition_type(&body.file, &content_type),
+						content_disposition_type(&body.file, &body.content_type),
 						sanitise_filename(filename.to_owned())
 					)
 				})
 				.as_deref(),
-			content_type.as_deref(),
+			body.content_type.as_deref(),
 			&body.file,
 		)
 		.await?;
@@ -193,7 +189,6 @@ pub(crate) async fn get_content_route(body: Ruma<get_content::v3::Request>) -> R
 	}) = services().media.get(mxc.clone()).await?
 	{
 		let content_disposition = Some(make_content_disposition(&file, &content_type, content_disposition, None));
-		let content_type = Some(make_content_type(&file, &content_type).to_owned());
 
 		Ok(get_content::v3::Response {
 			file,
@@ -222,11 +217,10 @@ pub(crate) async fn get_content_route(body: Ruma<get_content::v3::Request>) -> R
 			response.content_disposition,
 			None,
 		));
-		let content_type = Some(make_content_type(&response.file, &response.content_type).to_owned());
 
 		Ok(get_content::v3::Response {
 			file: response.file,
-			content_type,
+			content_type: response.content_type,
 			content_disposition,
 			cross_origin_resource_policy: Some(CORP_CROSS_ORIGIN.to_owned()),
 			cache_control: Some(CACHE_CONTROL_IMMUTABLE.to_owned()),
@@ -279,7 +273,6 @@ pub(crate) async fn get_content_as_filename_route(
 			content_disposition,
 			Some(body.filename.clone()),
 		));
-		let content_type = Some(make_content_type(&file, &content_type).to_owned());
 
 		Ok(get_content_as_filename::v3::Response {
 			file,
@@ -305,13 +298,10 @@ pub(crate) async fn get_content_as_filename_route(
 					remote_content_response.content_disposition,
 					None,
 				));
-				let content_type = Some(
-					make_content_type(&remote_content_response.file, &remote_content_response.content_type).to_owned(),
-				);
 
 				Ok(get_content_as_filename::v3::Response {
 					content_disposition,
-					content_type,
+					content_type: remote_content_response.content_type,
 					file: remote_content_response.file,
 					cross_origin_resource_policy: Some(CORP_CROSS_ORIGIN.to_owned()),
 					cache_control: Some(CACHE_CONTROL_IMMUTABLE.into()),
@@ -376,7 +366,6 @@ pub(crate) async fn get_content_thumbnail_route(
 		.await?
 	{
 		let content_disposition = Some(make_content_disposition(&file, &content_type, content_disposition, None));
-		let content_type = Some(make_content_type(&file, &content_type).to_owned());
 
 		Ok(get_content_thumbnail::v3::Response {
 			file,
@@ -434,13 +423,10 @@ pub(crate) async fn get_content_thumbnail_route(
 					get_thumbnail_response.content_disposition,
 					None,
 				));
-				let content_type = Some(
-					make_content_type(&get_thumbnail_response.file, &get_thumbnail_response.content_type).to_owned(),
-				);
 
 				Ok(get_content_thumbnail::v3::Response {
 					file: get_thumbnail_response.file,
-					content_type,
+					content_type: get_thumbnail_response.content_type,
 					cross_origin_resource_policy: Some(CORP_CROSS_ORIGIN.to_owned()),
 					cache_control: Some(CACHE_CONTROL_IMMUTABLE.to_owned()),
 					content_disposition,
@@ -509,22 +495,20 @@ async fn get_remote_content(
 		None,
 	));
 
-	let content_type = Some(make_content_type(&content_response.file, &content_response.content_type).to_owned());
-
 	services()
 		.media
 		.create(
 			None,
 			mxc.to_owned(),
 			content_disposition.as_deref(),
-			content_type.as_deref(),
+			content_response.content_type.as_deref(),
 			&content_response.file,
 		)
 		.await?;
 
 	Ok(get_content::v3::Response {
 		file: content_response.file,
-		content_type,
+		content_type: content_response.content_type,
 		content_disposition,
 		cross_origin_resource_policy: Some(CORP_CROSS_ORIGIN.to_owned()),
 		cache_control: Some(CACHE_CONTROL_IMMUTABLE.to_owned()),

src/core/utils/content_disposition.rs

@@ -2,8 +2,6 @@
 
 const ATTACHMENT: &str = "attachment";
 const INLINE: &str = "inline";
-const APPLICATION_OCTET_STREAM: &str = "application/octet-stream";
-const IMAGE_SVG_XML: &str = "image/svg+xml";
 
 /// as defined by MSC2702
 const ALLOWED_INLINE_CONTENT_TYPES: [&str; 26] = [
@@ -56,29 +54,6 @@ pub fn content_disposition_type(buf: &[u8], content_type: &Option<String>) -> &'
 	}
 }
 
-/// overrides the Content-Type with what we detected
-///
-/// SVG is special-cased due to the MIME type being classified as `text/xml` but
-/// browsers need `image/svg+xml`
-#[must_use]
-#[tracing::instrument(skip(buf))]
-pub fn make_content_type(buf: &[u8], content_type: &Option<String>) -> &'static str {
-	let Some(claimed_content_type) = content_type else {
-		return APPLICATION_OCTET_STREAM;
-	};
-
-	let Some(file_type) = infer::get(buf) else {
-		debug_info!("Failed to infer the file's contents");
-		return APPLICATION_OCTET_STREAM;
-	};
-
-	if claimed_content_type.contains("svg") && file_type.mime_type().contains("xml") {
-		return IMAGE_SVG_XML;
-	}
-
-	file_type.mime_type()
-}
-
 /// sanitises the file name for the Content-Disposition using
 /// `sanitize_filename` crate
 #[tracing::instrument]