enhance(server): better content type detection

2 files changed, 7 insertions, 4 deletions

diff --git a/packages/backend/src/server/file/send-drive-file.ts b/packages/backend/src/server/file/send-drive-file.ts
index 8bb5655b4f..1f88d9e315 100644
--- a/packages/backend/src/server/file/send-drive-file.ts
+++ b/packages/backend/src/server/file/send-drive-file.ts
@@ -14,6 +14,7 @@ import { detectType } from '@/misc/get-file-info';
 import { convertToJpeg, convertToPngOrJpeg } from '@/services/drive/image-processor';
 import { GenerateVideoThumbnail } from '@/services/drive/generate-video-thumbnail';
 import { StatusError } from '@/misc/fetch';
+import { FILE_TYPE_WHITELIST } from '@/const';
 
 //const _filename = fileURLToPath(import.meta.url);
 const _filename = __filename;
@@ -27,6 +28,7 @@ const commonReadableHandlerGenerator = (ctx: Koa.Context) => (e: Error): void =>
 	ctx.set('Cache-Control', 'max-age=300');
 };
 
+// eslint-disable-next-line import/no-default-export
 export default async function(ctx: Koa.Context) {
 	const key = ctx.params.key;
 
@@ -81,7 +83,7 @@ export default async function(ctx: Koa.Context) {
 
 				const image = await convertFile();
 				ctx.body = image.data;
-				ctx.set('Content-Type', image.type);
+				ctx.set('Content-Type', FILE_TYPE_WHITELIST.includes(image.type) ? image.type : 'application/octet-stream');
 				ctx.set('Cache-Control', 'max-age=31536000, immutable');
 			} catch (e) {
 				serverLogger.error(`${e}`);
@@ -112,14 +114,14 @@ export default async function(ctx: Koa.Context) {
 		}).toString();
 
 		ctx.body = InternalStorage.read(key);
-		ctx.set('Content-Type', mime);
+		ctx.set('Content-Type', FILE_TYPE_WHITELIST.includes(mime) ? mime : 'application/octet-stream');
 		ctx.set('Cache-Control', 'max-age=31536000, immutable');
 		ctx.set('Content-Disposition', contentDisposition('inline', filename));
 	} else {
 		const readable = InternalStorage.read(file.accessKey!);
 		readable.on('error', commonReadableHandlerGenerator(ctx));
 		ctx.body = readable;
-		ctx.set('Content-Type', file.type);
+		ctx.set('Content-Type', FILE_TYPE_WHITELIST.includes(file.type) ? file.type : 'application/octet-stream');
 		ctx.set('Cache-Control', 'max-age=31536000, immutable');
 		ctx.set('Content-Disposition', contentDisposition('inline', file.name));
 	}
diff --git a/packages/backend/src/server/proxy/proxy-media.ts b/packages/backend/src/server/proxy/proxy-media.ts
index 9e13c0877f..7d6652a97a 100644
--- a/packages/backend/src/server/proxy/proxy-media.ts
+++ b/packages/backend/src/server/proxy/proxy-media.ts
@@ -6,6 +6,7 @@ import { createTemp } from '@/misc/create-temp';
 import { downloadUrl } from '@/misc/download-url';
 import { detectType } from '@/misc/get-file-info';
 import { StatusError } from '@/misc/fetch';
+import { FILE_TYPE_WHITELIST } from '@/const';
 
 export async function proxyMedia(ctx: Koa.Context) {
 	const url = 'url' in ctx.query ? ctx.query.url : 'https://' + ctx.params.url;
@@ -18,7 +19,7 @@ export async function proxyMedia(ctx: Koa.Context) {
 
 		const { mime, ext } = await detectType(path);
 
-		if (!mime.startsWith('image/')) throw 403;
+		if (!FILE_TYPE_WHITELIST.includes(mime)) throw 403;
 
 		let image: IImage;