파일 업로드 스케쥴링 구현

암호화는 동시에 최대 4개까지, 업로드는 1개까지 가능하도록 설정했습니다.

src/lib/modules/file/index.ts

@@ -0,0 +1,3 @@
+export * from "./cache";
+export * from "./info";
+export * from "./upload";

src/lib/modules/file/upload.ts

@@ -0,0 +1,221 @@
+import axios from "axios";
+import ExifReader from "exifreader";
+import { limitFunction } from "p-limit";
+import { writable, type Writable } from "svelte/store";
+import {
+  encodeToBase64,
+  generateDataKey,
+  wrapDataKey,
+  encryptData,
+  encryptString,
+  signMessageHmac,
+} from "$lib/modules/crypto";
+import type {
+  DuplicateFileScanRequest,
+  DuplicateFileScanResponse,
+  FileUploadRequest,
+} from "$lib/server/schemas";
+import {
+  fileUploadStatusStore,
+  type MasterKey,
+  type HmacSecret,
+  type FileUploadStatus,
+} from "$lib/stores";
+
+const requestDuplicateFileScan = limitFunction(
+  async (file: File, hmacSecret: HmacSecret, onDuplicate: () => Promise<boolean>) => {
+    const fileBuffer = await file.arrayBuffer();
+    const fileSigned = encodeToBase64(await signMessageHmac(fileBuffer, hmacSecret.secret));
+
+    const res = await axios.post("/api/file/scanDuplicates", {
+      hskVersion: hmacSecret.version,
+      contentHmac: fileSigned,
+    } satisfies DuplicateFileScanRequest);
+    const { files }: DuplicateFileScanResponse = res.data;
+
+    if (files.length === 0 || (await onDuplicate())) {
+      return { fileBuffer, fileSigned };
+    } else {
+      return {};
+    }
+  },
+  { concurrency: 1 },
+);
+
+const getFileType = (file: File) => {
+  if (file.type) return file.type;
+  if (file.name.endsWith(".heic")) return "image/heic";
+  throw new Error("Unknown file type");
+};
+
+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.. Assume 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);
+};
+
+const encryptFile = limitFunction(
+  async (
+    status: Writable<FileUploadStatus>,
+    file: File,
+    fileBuffer: ArrayBuffer,
+    masterKey: MasterKey,
+  ) => {
+    status.update((value) => {
+      value.status = "encrypting";
+      return value;
+    });
+
+    const fileType = getFileType(file);
+
+    let createdAt;
+    if (fileType.startsWith("image/")) {
+      createdAt = extractExifDateTime(fileBuffer);
+    }
+
+    const { dataKey, dataKeyVersion } = await generateDataKey();
+    const dataKeyWrapped = await wrapDataKey(dataKey, masterKey.key);
+
+    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);
+
+    status.update((value) => {
+      value.status = "upload-pending";
+      return value;
+    });
+
+    return {
+      dataKeyWrapped,
+      dataKeyVersion,
+      fileEncrypted,
+      fileType,
+      nameEncrypted,
+      createdAtEncrypted,
+      lastModifiedAtEncrypted,
+    };
+  },
+  { concurrency: 4 },
+);
+
+const uploadFileInternal = limitFunction(
+  async (status: Writable<FileUploadStatus>, form: FormData) => {
+    status.update((value) => {
+      value.status = "uploading";
+      return value;
+    });
+
+    await axios.post("/api/file/upload", form, {
+      onUploadProgress: ({ progress, rate, estimated }) => {
+        status.update((value) => {
+          value.progress = progress;
+          value.rate = rate;
+          value.estimated = estimated;
+          return value;
+        });
+      },
+    });
+
+    status.update((value) => {
+      value.status = "uploaded";
+      return value;
+    });
+  },
+  { concurrency: 1 },
+);
+
+export const uploadFile = async (
+  file: File,
+  parentId: "root" | number,
+  hmacSecret: HmacSecret,
+  masterKey: MasterKey,
+  onDuplicate: () => Promise<boolean>,
+) => {
+  const status = writable<FileUploadStatus>({
+    name: file.name,
+    parentId,
+    status: "encryption-pending",
+  });
+  fileUploadStatusStore.update((value) => {
+    value.push(status);
+    return value;
+  });
+
+  try {
+    const { fileBuffer, fileSigned } = await requestDuplicateFileScan(
+      file,
+      hmacSecret,
+      onDuplicate,
+    );
+    if (!fileBuffer || !fileSigned) {
+      status.update((value) => {
+        value.status = "canceled";
+        return value;
+      });
+      return false;
+    }
+
+    const {
+      dataKeyWrapped,
+      dataKeyVersion,
+      fileEncrypted,
+      fileType,
+      nameEncrypted,
+      createdAtEncrypted,
+      lastModifiedAtEncrypted,
+    } = await encryptFile(status, file, fileBuffer, masterKey);
+
+    const form = new FormData();
+    form.set(
+      "metadata",
+      JSON.stringify({
+        parentId,
+        mekVersion: masterKey.version,
+        dek: dataKeyWrapped,
+        dekVersion: dataKeyVersion.toISOString(),
+        hskVersion: hmacSecret.version,
+        contentHmac: fileSigned,
+        contentType: fileType,
+        contentIv: fileEncrypted.iv,
+        name: nameEncrypted.ciphertext,
+        nameIv: nameEncrypted.iv,
+        createdAt: createdAtEncrypted?.ciphertext,
+        createdAtIv: createdAtEncrypted?.iv,
+        lastModifiedAt: lastModifiedAtEncrypted.ciphertext,
+        lastModifiedAtIv: lastModifiedAtEncrypted.iv,
+      } as FileUploadRequest),
+    );
+    form.set("content", new Blob([fileEncrypted.ciphertext]));
+
+    await uploadFileInternal(status, form);
+    return true;
+  } catch (e) {
+    status.update((value) => {
+      value.status = "error";
+      return value;
+    });
+    throw e;
+  }
+};