파일 생성 시각 및 파일 마지막 수정 시각을 저장하도록 변경

파일 마지막 수정 시각은 반드시 지정되어야 하며, 파일 시스템에서 읽어옵니다. 파일 생성 시각은 선택적으로 지정될 수 있으며, 이미지일 경우 EXIF에서 추출을 시도합니다. 두 값 모두 클라이언트에서 암호화되어 서버에 저장됩니다.

src/routes/(main)/directory/[[id]]/service.ts

@@ -1,3 +1,4 @@
+import ExifReader from "exifreader";
 import { callGetApi, callPostApi } from "$lib/hooks";
 import { storeHmacSecrets } from "$lib/indexedDB";
 import {
@@ -82,6 +83,32 @@ export const requestDuplicateFileScan = async (file: File, hmacSecret: HmacSecre
   };
 };
 
+const extractExifDateTime = (fileBuffer: ArrayBuffer) => {
+  const exif = ExifReader.load(fileBuffer);
+  const dateTimeOriginal = exif["DateTimeOriginal"]?.description;
+  const offsetTimeOriginal = exif["OffsetTimeOriginal"]?.description;
+  if (!dateTimeOriginal) return undefined;
+
+  const [date, time] = dateTimeOriginal.split(" ");
+  if (!date || !time) return undefined;
+
+  const [year, month, day] = date.split(":").map(Number);
+  const [hour, minute, second] = time.split(":").map(Number);
+  if (!year || !month || !day || !hour || !minute || !second) return undefined;
+
+  if (!offsetTimeOriginal) {
+    // No timezone information -> Local timezone
+    return new Date(year, month - 1, day, hour, minute, second);
+  }
+
+  const offsetSign = offsetTimeOriginal[0] === "+" ? 1 : -1;
+  const [offsetHour, offsetMinute] = offsetTimeOriginal.slice(1).split(":").map(Number);
+
+  const utcDate = Date.UTC(year, month - 1, day, hour, minute, second);
+  const offsetMs = offsetSign * ((offsetHour ?? 0) * 60 + (offsetMinute ?? 0)) * 60 * 1000;
+  return new Date(utcDate - offsetMs);
+};
+
 export const requestFileUpload = async (
   file: File,
   fileBuffer: ArrayBuffer,
@@ -90,9 +117,17 @@ export const requestFileUpload = async (
   masterKey: MasterKey,
   hmacSecret: HmacSecret,
 ) => {
+  let createdAt = undefined;
+  if (file.type.startsWith("image/")) {
+    createdAt = extractExifDateTime(fileBuffer);
+  }
+
   const { dataKey, dataKeyVersion } = await generateDataKey();
-  const nameEncrypted = await encryptString(file.name, dataKey);
   const fileEncrypted = await encryptData(fileBuffer, dataKey);
+  const nameEncrypted = await encryptString(file.name, dataKey);
+  const createdAtEncrypted =
+    createdAt && (await encryptString(createdAt.getTime().toString(), dataKey));
+  const lastModifiedAtEncrypted = await encryptString(file.lastModified.toString(), dataKey);
 
   const form = new FormData();
   form.set(
@@ -108,6 +143,10 @@ export const requestFileUpload = async (
       contentIv: fileEncrypted.iv,
       name: nameEncrypted.ciphertext,
       nameIv: nameEncrypted.iv,
+      createdAt: createdAtEncrypted?.ciphertext,
+      createdAtIv: createdAtEncrypted?.iv,
+      lastModifiedAt: lastModifiedAtEncrypted.ciphertext,
+      lastModifiedAtIv: lastModifiedAtEncrypted.iv,
     } satisfies FileUploadRequest),
   );
   form.set("content", new Blob([fileEncrypted.ciphertext]));