media: drop Content-Type detection support

Signed-off-by: strawberry <[email protected]>

Cargo.toml

@@ -28,10 +28,6 @@ name = "conduit"
 [workspace.dependencies.sanitize-filename]
 version = "0.5.0"
 
-[workspace.dependencies.infer]
-version = "0.16"
-default-features = false
-
 [workspace.dependencies.jsonwebtoken]
 version = "9.3.0"
 

src/api/client_server/media.rs

@@ -139,7 +139,7 @@ pub(crate) async fn create_content_route(
 				.map(|filename| {
 					format!(
 						"{}; filename={}",
-						content_disposition_type(&body.file, &body.content_type),
+						content_disposition_type(&body.content_type),
 						sanitise_filename(filename.to_owned())
 					)
 				})
@@ -188,7 +188,7 @@ pub(crate) async fn get_content_route(body: Ruma<get_content::v3::Request>) -> R
 		content_disposition,
 	}) = services().media.get(mxc.clone()).await?
 	{
-		let content_disposition = Some(make_content_disposition(&file, &content_type, content_disposition, None));
+		let content_disposition = Some(make_content_disposition(&content_type, content_disposition, None));
 
 		Ok(get_content::v3::Response {
 			file,
@@ -212,7 +212,6 @@ pub(crate) async fn get_content_route(body: Ruma<get_content::v3::Request>) -> R
 		})?;
 
 		let content_disposition = Some(make_content_disposition(
-			&response.file,
 			&response.content_type,
 			response.content_disposition,
 			None,
@@ -268,7 +267,6 @@ pub(crate) async fn get_content_as_filename_route(
 	}) = services().media.get(mxc.clone()).await?
 	{
 		let content_disposition = Some(make_content_disposition(
-			&file,
 			&content_type,
 			content_disposition,
 			Some(body.filename.clone()),
@@ -293,7 +291,6 @@ pub(crate) async fn get_content_as_filename_route(
 		{
 			Ok(remote_content_response) => {
 				let content_disposition = Some(make_content_disposition(
-					&remote_content_response.file,
 					&remote_content_response.content_type,
 					remote_content_response.content_disposition,
 					None,
@@ -365,7 +362,7 @@ pub(crate) async fn get_content_thumbnail_route(
 		)
 		.await?
 	{
-		let content_disposition = Some(make_content_disposition(&file, &content_type, content_disposition, None));
+		let content_disposition = Some(make_content_disposition(&content_type, content_disposition, None));
 
 		Ok(get_content_thumbnail::v3::Response {
 			file,
@@ -418,7 +415,6 @@ pub(crate) async fn get_content_thumbnail_route(
 					.await?;
 
 				let content_disposition = Some(make_content_disposition(
-					&get_thumbnail_response.file,
 					&get_thumbnail_response.content_type,
 					get_thumbnail_response.content_disposition,
 					None,
@@ -489,7 +485,6 @@ async fn get_remote_content(
 		.await?;
 
 	let content_disposition = Some(make_content_disposition(
-		&content_response.file,
 		&content_response.content_type,
 		content_response.content_disposition,
 		None,

src/core/Cargo.toml

@@ -68,7 +68,6 @@ figment.workspace = true
 http-body-util.workspace = true
 http.workspace = true
 image.workspace = true
-infer.workspace = true
 ipaddress.workspace = true
 itertools.workspace = true
 libloading.workspace = true

src/core/utils/content_disposition.rs

@@ -1,5 +1,3 @@
-use crate::debug_info;
-
 const ATTACHMENT: &str = "attachment";
 const INLINE: &str = "inline";
 
@@ -35,19 +33,17 @@ const ALLOWED_INLINE_CONTENT_TYPES: [&str; 26] = [
 ];
 
 /// Returns a Content-Disposition of `attachment` or `inline`, depending on the
-/// *parsed* contents of the file uploaded via format magic keys using `infer`
-/// crate (basically libmagic without needing libmagic).
+/// Content-Type against MSC2702 list of safe inline Content-Types
+/// (`ALLOWED_INLINE_CONTENT_TYPES`)
 #[must_use]
-#[tracing::instrument(skip(buf))]
-pub fn content_disposition_type(buf: &[u8], content_type: &Option<String>) -> &'static str {
-	let Some(file_type) = infer::get(buf) else {
-		debug_info!("Failed to infer the file's contents, assuming attachment for Content-Disposition");
+#[tracing::instrument]
+pub fn content_disposition_type(content_type: &Option<String>) -> &'static str {
+	let Some(content_type) = content_type else {
+		// no Content-Type was given to us, assume attachment
 		return ATTACHMENT;
 	};
 
-	debug_info!("detected MIME type: {}", file_type.mime_type());
-
-	if ALLOWED_INLINE_CONTENT_TYPES.contains(&file_type.mime_type()) {
+	if ALLOWED_INLINE_CONTENT_TYPES.contains(&content_type.as_str()) {
 		INLINE
 	} else {
 		ATTACHMENT
@@ -74,9 +70,9 @@ pub fn sanitise_filename(filename: String) -> String {
 /// `Content-Disposition: attachment/inline; filename=filename.ext`
 ///
 /// else: `Content-Disposition: attachment/inline`
-#[tracing::instrument(skip(file))]
+#[tracing::instrument]
 pub fn make_content_disposition(
-	file: &[u8], content_type: &Option<String>, content_disposition: Option<String>, req_filename: Option<String>,
+	content_type: &Option<String>, content_disposition: Option<String>, req_filename: Option<String>,
 ) -> String {
 	let filename: String;
 
@@ -98,10 +94,10 @@ pub fn make_content_disposition(
 
 	if !filename.is_empty() {
 		// Content-Disposition: attachment/inline; filename=filename.ext
-		format!("{}; filename={}", content_disposition_type(file, content_type), filename)
+		format!("{}; filename={}", content_disposition_type(content_type), filename)
 	} else {
 		// Content-Disposition: attachment/inline
-		String::from(content_disposition_type(file, content_type))
+		String::from(content_disposition_type(content_type))
 	}
 }