Merge pull request #19 from kmc7468/dev

v0.8.0
2026-02-03 23:56:53 +00:00 · 2026-01-13 00:29:14 +09:00
parent 3906ec4371 b952bfae86
commit 7b621d6e98
96 changed files with 2643 additions and 1103 deletions
--- a/.dockerignore
+++ b/.dockerignore
@@ -12,6 +12,7 @@ node_modules
 /data
 /library
 /thumbnails
+/uploads

 # OS
 .DS_Store
--- a/.env.example
+++ b/.env.example
@@ -12,3 +12,4 @@ USER_CLIENT_CHALLENGE_EXPIRES=
 SESSION_UPGRADE_CHALLENGE_EXPIRES=
 LIBRARY_PATH=
 THUMBNAILS_PATH=
+UPLOADS_PATH=
--- a/.github/workflows/docker.yaml
+++ b/.github/workflows/docker.yaml
@@ -0,0 +1,45 @@
+name: Docker Image Build
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract Docker metadata
+        uses: docker/metadata-action@v5
+        id: meta
+        with:
+          images: ghcr.io/${{ github.repository }}
+          tags: |
+            type=semver,value={{version}}
+            type=raw,value=latest
+            type=sha
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
--- a/.gitignore
+++ b/.gitignore
@@ -10,6 +10,7 @@ node_modules
 /data
 /library
 /thumbnails
+/uploads

 # OS
 .DS_Store
--- a/docker-compose.yaml
+++ b/docker-compose.yaml
@@ -9,6 +9,7 @@ services:
    volumes:
      - ./data/library:/app/data/library
      - ./data/thumbnails:/app/data/thumbnails
+      - ./data/uploads:/app/data/uploads
    environment:
      # ArkVault
      - DATABASE_HOST=database
@@ -20,6 +21,7 @@ services:
      - SESSION_UPGRADE_CHALLENGE_EXPIRES
      - LIBRARY_PATH=/app/data/library
      - THUMBNAILS_PATH=/app/data/thumbnails
+      - UPLOADS_PATH=/app/data/uploads
      # SvelteKit
      - ADDRESS_HEADER=${TRUST_PROXY:+X-Forwarded-For}
      - XFF_DEPTH=${TRUST_PROXY:-}
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
  "name": "arkvault",
  "private": true,
-  "version": "0.7.0",
+  "version": "0.8.0",
  "type": "module",
  "scripts": {
    "dev": "vite dev",
@@ -16,13 +16,14 @@
    "db:migrate": "kysely migrate"
  },
  "devDependencies": {
-    "@eslint/compat": "^2.0.0",
+    "@eslint/compat": "^2.0.1",
    "@eslint/js": "^9.39.2",
-    "@iconify-json/material-symbols": "^1.2.50",
+    "@iconify-json/material-symbols": "^1.2.51",
+    "@noble/hashes": "^2.0.1",
    "@sveltejs/adapter-node": "^5.4.0",
-    "@sveltejs/kit": "^2.49.2",
-    "@sveltejs/vite-plugin-svelte": "^6.2.1",
-    "@tanstack/svelte-virtual": "^3.13.16",
+    "@sveltejs/kit": "^2.49.4",
+    "@sveltejs/vite-plugin-svelte": "^6.2.4",
+    "@tanstack/svelte-virtual": "^3.13.18",
    "@trpc/client": "^11.8.1",
    "@types/file-saver": "^2.0.7",
    "@types/ms": "^0.7.34",
@@ -33,11 +34,11 @@
    "dexie": "^4.2.1",
    "eslint": "^9.39.2",
    "eslint-config-prettier": "^10.1.8",
-    "eslint-plugin-svelte": "^3.13.1",
+    "eslint-plugin-svelte": "^3.14.0",
    "eslint-plugin-tailwindcss": "^3.18.2",
-    "exifreader": "^4.33.1",
+    "exifreader": "^4.35.0",
    "file-saver": "^2.0.5",
-    "globals": "^16.5.0",
+    "globals": "^17.0.0",
    "heic2any": "^0.0.4",
    "kysely-ctl": "^0.19.0",
    "lru-cache": "^11.2.4",
@@ -50,12 +51,11 @@
    "svelte-check": "^4.3.5",
    "tailwindcss": "^3.4.19",
    "typescript": "^5.9.3",
-    "typescript-eslint": "^8.51.0",
+    "typescript-eslint": "^8.52.0",
    "unplugin-icons": "^22.5.0",
-    "vite": "^7.3.0"
+    "vite": "^7.3.1"
  },
  "dependencies": {
-    "@fastify/busboy": "^3.2.0",
    "@trpc/server": "^11.8.1",
    "argon2": "^0.44.0",
    "kysely": "^0.28.9",
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
--- a/src/hooks.client.ts
+++ b/src/hooks.client.ts
@@ -1,7 +1,6 @@
 import type { ClientInit } from "@sveltejs/kit";
 import { cleanupDanglingInfos, getClientKey, getMasterKeys, getHmacSecrets } from "$lib/indexedDB";
 import { prepareFileCache } from "$lib/modules/file";
-import { prepareOpfs } from "$lib/modules/opfs";
 import { clientKeyStore, masterKeyStore, hmacSecretStore } from "$lib/stores";

 const requestPersistentStorage = async () => {
@@ -46,7 +45,6 @@ export const init: ClientInit = async () => {
    prepareClientKeyStore(),
    prepareMasterKeyStore(),
    prepareHmacSecretStore(),
-    prepareOpfs(),
  ]);

  cleanupDanglingInfos(); // Intended
--- a/src/hooks.server.ts
+++ b/src/hooks.server.ts
@@ -8,6 +8,7 @@ import {
  cleanupExpiredSessionUpgradeChallenges,
 } from "$lib/server/db/session";
 import { authenticate, setAgentInfo } from "$lib/server/middlewares";
+import { cleanupExpiredUploadSessions } from "$lib/server/services/upload";

 export const init: ServerInit = async () => {
  await migrateDB();
@@ -16,6 +17,7 @@ export const init: ServerInit = async () => {
    cleanupExpiredUserClientChallenges();
    cleanupExpiredSessions();
    cleanupExpiredSessionUpgradeChallenges();
+    cleanupExpiredUploadSessions();
  });
 };

--- a/src/lib/constants/index.ts
+++ b/src/lib/constants/index.ts
@@ -0,0 +1,2 @@
+export * from "./serviceWorker";
+export * from "./upload";
--- a/src/lib/constants/serviceWorker.ts
+++ b/src/lib/constants/serviceWorker.ts
@@ -0,0 +1 @@
+export const DECRYPTED_FILE_URL_PREFIX = "/_internal/decryptedFile/";
--- a/src/lib/constants/upload.ts
+++ b/src/lib/constants/upload.ts
@@ -0,0 +1,6 @@
+export const AES_GCM_IV_SIZE = 12;
+export const AES_GCM_TAG_SIZE = 16;
+export const ENCRYPTION_OVERHEAD = AES_GCM_IV_SIZE + AES_GCM_TAG_SIZE;
+
+export const CHUNK_SIZE = 4 * 1024 * 1024; // 4 MiB
+export const ENCRYPTED_CHUNK_SIZE = CHUNK_SIZE + ENCRYPTION_OVERHEAD;
--- a/src/lib/indexedDB/keyStore.ts
+++ b/src/lib/indexedDB/keyStore.ts
@@ -70,12 +70,12 @@ export const storeMasterKeys = async (keys: MasterKey[]) => {
 };

 export const getHmacSecrets = async () => {
-  return await keyStore.hmacSecret.toArray();
+  return (await keyStore.hmacSecret.toArray()).filter(({ secret }) => secret.extractable);
 };

 export const storeHmacSecrets = async (secrets: HmacSecret[]) => {
-  if (secrets.some(({ secret }) => secret.extractable)) {
-    throw new Error("Hmac secrets must be nonextractable");
+  if (secrets.some(({ secret }) => !secret.extractable)) {
+    throw new Error("Hmac secrets must be extractable");
  }
  await keyStore.hmacSecret.bulkPut(secrets);
 };
--- a/src/lib/modules/crypto/aes.ts
+++ b/src/lib/modules/crypto/aes.ts
@@ -1,8 +1,15 @@
-import { encodeString, decodeString, encodeToBase64, decodeFromBase64 } from "./util";
+import { AES_GCM_IV_SIZE } from "$lib/constants";
+import {
+  encodeString,
+  decodeString,
+  encodeToBase64,
+  decodeFromBase64,
+  concatenateBuffers,
+} from "./utils";

 export const generateMasterKey = async () => {
  return {
-    masterKey: await window.crypto.subtle.generateKey(
+    masterKey: await crypto.subtle.generateKey(
      {
        name: "AES-KW",
        length: 256,
@@ -15,7 +22,7 @@ export const generateMasterKey = async () => {

 export const generateDataKey = async () => {
  return {
-    dataKey: await window.crypto.subtle.generateKey(
+    dataKey: await crypto.subtle.generateKey(
      {
        name: "AES-GCM",
        length: 256,
@@ -28,9 +35,9 @@ export const generateDataKey = async () => {
 };

 export const makeAESKeyNonextractable = async (key: CryptoKey) => {
-  return await window.crypto.subtle.importKey(
+  return await crypto.subtle.importKey(
    "raw",
-    await window.crypto.subtle.exportKey("raw", key),
+    await crypto.subtle.exportKey("raw", key),
    key.algorithm,
    false,
    key.usages,
@@ -38,12 +45,12 @@ export const makeAESKeyNonextractable = async (key: CryptoKey) => {
 };

 export const wrapDataKey = async (dataKey: CryptoKey, masterKey: CryptoKey) => {
-  return encodeToBase64(await window.crypto.subtle.wrapKey("raw", dataKey, masterKey, "AES-KW"));
+  return encodeToBase64(await crypto.subtle.wrapKey("raw", dataKey, masterKey, "AES-KW"));
 };

 export const unwrapDataKey = async (dataKeyWrapped: string, masterKey: CryptoKey) => {
  return {
-    dataKey: await window.crypto.subtle.unwrapKey(
+    dataKey: await crypto.subtle.unwrapKey(
      "raw",
      decodeFromBase64(dataKeyWrapped),
      masterKey,
@@ -56,12 +63,12 @@ export const unwrapDataKey = async (dataKeyWrapped: string, masterKey: CryptoKey
 };

 export const wrapHmacSecret = async (hmacSecret: CryptoKey, masterKey: CryptoKey) => {
-  return encodeToBase64(await window.crypto.subtle.wrapKey("raw", hmacSecret, masterKey, "AES-KW"));
+  return encodeToBase64(await crypto.subtle.wrapKey("raw", hmacSecret, masterKey, "AES-KW"));
 };

 export const unwrapHmacSecret = async (hmacSecretWrapped: string, masterKey: CryptoKey) => {
  return {
-    hmacSecret: await window.crypto.subtle.unwrapKey(
+    hmacSecret: await crypto.subtle.unwrapKey(
      "raw",
      decodeFromBase64(hmacSecretWrapped),
      masterKey,
@@ -70,15 +77,15 @@ export const unwrapHmacSecret = async (hmacSecretWrapped: string, masterKey: Cry
        name: "HMAC",
        hash: "SHA-256",
      } satisfies HmacImportParams,
-      false, // Nonextractable
+      true, // Extractable
      ["sign", "verify"],
    ),
  };
 };

 export const encryptData = async (data: BufferSource, dataKey: CryptoKey) => {
-  const iv = window.crypto.getRandomValues(new Uint8Array(12));
-  const ciphertext = await window.crypto.subtle.encrypt(
+  const iv = crypto.getRandomValues(new Uint8Array(12));
+  const ciphertext = await crypto.subtle.encrypt(
    {
      name: "AES-GCM",
      iv,
@@ -86,14 +93,18 @@ export const encryptData = async (data: BufferSource, dataKey: CryptoKey) => {
    dataKey,
    data,
  );
-  return { ciphertext, iv: encodeToBase64(iv.buffer) };
+  return { ciphertext, iv: iv.buffer };
 };

-export const decryptData = async (ciphertext: BufferSource, iv: string, dataKey: CryptoKey) => {
-  return await window.crypto.subtle.decrypt(
+export const decryptData = async (
+  ciphertext: BufferSource,
+  iv: string | BufferSource,
+  dataKey: CryptoKey,
+) => {
+  return await crypto.subtle.decrypt(
    {
      name: "AES-GCM",
-      iv: decodeFromBase64(iv),
+      iv: typeof iv === "string" ? decodeFromBase64(iv) : iv,
    } satisfies AesGcmParams,
    dataKey,
    ciphertext,
@@ -102,9 +113,22 @@ export const decryptData = async (ciphertext: BufferSource, iv: string, dataKey:

 export const encryptString = async (plaintext: string, dataKey: CryptoKey) => {
  const { ciphertext, iv } = await encryptData(encodeString(plaintext), dataKey);
-  return { ciphertext: encodeToBase64(ciphertext), iv };
+  return { ciphertext: encodeToBase64(ciphertext), iv: encodeToBase64(iv) };
 };

 export const decryptString = async (ciphertext: string, iv: string, dataKey: CryptoKey) => {
  return decodeString(await decryptData(decodeFromBase64(ciphertext), iv, dataKey));
 };
+
+export const encryptChunk = async (chunk: ArrayBuffer, dataKey: CryptoKey) => {
+  const { ciphertext, iv } = await encryptData(chunk, dataKey);
+  return concatenateBuffers(iv, ciphertext).buffer;
+};
+
+export const decryptChunk = async (encryptedChunk: ArrayBuffer, dataKey: CryptoKey) => {
+  return await decryptData(
+    encryptedChunk.slice(AES_GCM_IV_SIZE),
+    encryptedChunk.slice(0, AES_GCM_IV_SIZE),
+    dataKey,
+  );
+};
--- a/src/lib/modules/crypto/index.ts
+++ b/src/lib/modules/crypto/index.ts
@@ -1,4 +1,4 @@
 export * from "./aes";
 export * from "./rsa";
 export * from "./sha";
-export * from "./util";
+export * from "./utils";
--- a/src/lib/modules/crypto/rsa.ts
+++ b/src/lib/modules/crypto/rsa.ts
@@ -1,7 +1,7 @@
-import { encodeString, encodeToBase64, decodeFromBase64 } from "./util";
+import { encodeString, encodeToBase64, decodeFromBase64 } from "./utils";

 export const generateEncryptionKeyPair = async () => {
-  const keyPair = await window.crypto.subtle.generateKey(
+  const keyPair = await crypto.subtle.generateKey(
    {
      name: "RSA-OAEP",
      modulusLength: 4096,
@@ -18,7 +18,7 @@ export const generateEncryptionKeyPair = async () => {
 };

 export const generateSigningKeyPair = async () => {
-  const keyPair = await window.crypto.subtle.generateKey(
+  const keyPair = await crypto.subtle.generateKey(
    {
      name: "RSA-PSS",
      modulusLength: 4096,
@@ -37,7 +37,7 @@ export const generateSigningKeyPair = async () => {
 export const exportRSAKey = async (key: CryptoKey) => {
  const format = key.type === "public" ? ("spki" as const) : ("pkcs8" as const);
  return {
-    key: await window.crypto.subtle.exportKey(format, key),
+    key: await crypto.subtle.exportKey(format, key),
    format,
  };
 };
@@ -54,14 +54,14 @@ export const importEncryptionKeyPairFromBase64 = async (
    name: "RSA-OAEP",
    hash: "SHA-256",
  };
-  const encryptKey = await window.crypto.subtle.importKey(
+  const encryptKey = await crypto.subtle.importKey(
    "spki",
    decodeFromBase64(encryptKeyBase64),
    algorithm,
    true,
    ["encrypt", "wrapKey"],
  );
-  const decryptKey = await window.crypto.subtle.importKey(
+  const decryptKey = await crypto.subtle.importKey(
    "pkcs8",
    decodeFromBase64(decryptKeyBase64),
    algorithm,
@@ -79,14 +79,14 @@ export const importSigningKeyPairFromBase64 = async (
    name: "RSA-PSS",
    hash: "SHA-256",
  };
-  const signKey = await window.crypto.subtle.importKey(
+  const signKey = await crypto.subtle.importKey(
    "pkcs8",
    decodeFromBase64(signKeyBase64),
    algorithm,
    true,
    ["sign"],
  );
-  const verifyKey = await window.crypto.subtle.importKey(
+  const verifyKey = await crypto.subtle.importKey(
    "spki",
    decodeFromBase64(verifyKeyBase64),
    algorithm,
@@ -98,17 +98,11 @@ export const importSigningKeyPairFromBase64 = async (

 export const makeRSAKeyNonextractable = async (key: CryptoKey) => {
  const { key: exportedKey, format } = await exportRSAKey(key);
-  return await window.crypto.subtle.importKey(
-    format,
-    exportedKey,
-    key.algorithm,
-    false,
-    key.usages,
-  );
+  return await crypto.subtle.importKey(format, exportedKey, key.algorithm, false, key.usages);
 };

 export const decryptChallenge = async (challenge: string, decryptKey: CryptoKey) => {
-  return await window.crypto.subtle.decrypt(
+  return await crypto.subtle.decrypt(
    {
      name: "RSA-OAEP",
    } satisfies RsaOaepParams,
@@ -119,7 +113,7 @@ export const decryptChallenge = async (challenge: string, decryptKey: CryptoKey)

 export const wrapMasterKey = async (masterKey: CryptoKey, encryptKey: CryptoKey) => {
  return encodeToBase64(
-    await window.crypto.subtle.wrapKey("raw", masterKey, encryptKey, {
+    await crypto.subtle.wrapKey("raw", masterKey, encryptKey, {
      name: "RSA-OAEP",
    } satisfies RsaOaepParams),
  );
@@ -131,7 +125,7 @@ export const unwrapMasterKey = async (
  extractable = false,
 ) => {
  return {
-    masterKey: await window.crypto.subtle.unwrapKey(
+    masterKey: await crypto.subtle.unwrapKey(
      "raw",
      decodeFromBase64(masterKeyWrapped),
      decryptKey,
@@ -146,7 +140,7 @@ export const unwrapMasterKey = async (
 };

 export const signMessageRSA = async (message: BufferSource, signKey: CryptoKey) => {
-  return await window.crypto.subtle.sign(
+  return await crypto.subtle.sign(
    {
      name: "RSA-PSS",
      saltLength: 32, // SHA-256
@@ -161,7 +155,7 @@ export const verifySignatureRSA = async (
  signature: BufferSource,
  verifyKey: CryptoKey,
 ) => {
-  return await window.crypto.subtle.verify(
+  return await crypto.subtle.verify(
    {
      name: "RSA-PSS",
      saltLength: 32, // SHA-256
--- a/src/lib/modules/crypto/sha.ts
+++ b/src/lib/modules/crypto/sha.ts
@@ -1,10 +1,13 @@
+import HmacWorker from "$workers/hmac?worker";
+import type { ComputeMessage, ResultMessage } from "$workers/hmac";
+
 export const digestMessage = async (message: BufferSource) => {
-  return await window.crypto.subtle.digest("SHA-256", message);
+  return await crypto.subtle.digest("SHA-256", message);
 };

 export const generateHmacSecret = async () => {
  return {
-    hmacSecret: await window.crypto.subtle.generateKey(
+    hmacSecret: await crypto.subtle.generateKey(
      {
        name: "HMAC",
        hash: "SHA-256",
@@ -15,6 +18,24 @@ export const generateHmacSecret = async () => {
  };
 };

-export const signMessageHmac = async (message: BufferSource, hmacSecret: CryptoKey) => {
-  return await window.crypto.subtle.sign("HMAC", hmacSecret, message);
+export const signMessageHmac = async (message: Blob, hmacSecret: CryptoKey) => {
+  const stream = message.stream();
+  const hmacSecretRaw = new Uint8Array(await crypto.subtle.exportKey("raw", hmacSecret));
+  const worker = new HmacWorker();
+
+  return new Promise<Uint8Array>((resolve, reject) => {
+    worker.onmessage = ({ data }: MessageEvent<ResultMessage>) => {
+      resolve(data.result);
+      worker.terminate();
+    };
+
+    worker.onerror = ({ error }) => {
+      reject(error);
+      worker.terminate();
+    };
+
+    worker.postMessage({ stream, key: hmacSecretRaw } satisfies ComputeMessage, {
+      transfer: [stream, hmacSecretRaw.buffer],
+    });
+  });
 };
--- a/src/lib/modules/crypto/utils.ts
+++ b/src/lib/modules/crypto/utils.ts
@@ -9,8 +9,8 @@ export const decodeString = (data: ArrayBuffer) => {
  return textDecoder.decode(data);
 };

-export const encodeToBase64 = (data: ArrayBuffer) => {
-  return btoa(String.fromCharCode(...new Uint8Array(data)));
+export const encodeToBase64 = (data: ArrayBuffer | Uint8Array) => {
+  return btoa(String.fromCharCode(...(data instanceof ArrayBuffer ? new Uint8Array(data) : data)));
 };

 export const decodeFromBase64 = (data: string) => {
--- a/src/lib/modules/file/download.svelte.ts
+++ b/src/lib/modules/file/download.svelte.ts
@@ -1,6 +1,7 @@
 import axios from "axios";
 import { limitFunction } from "p-limit";
-import { decryptData } from "$lib/modules/crypto";
+import { ENCRYPTED_CHUNK_SIZE } from "$lib/constants";
+import { decryptChunk, concatenateBuffers } from "$lib/modules/crypto";

 export interface FileDownloadState {
  id: number;
@@ -65,13 +66,21 @@ const decryptFile = limitFunction(
  async (
    state: FileDownloadState,
    fileEncrypted: ArrayBuffer,
-    fileEncryptedIv: string,
+    encryptedChunkSize: number,
    dataKey: CryptoKey,
  ) => {
    state.status = "decrypting";

-    const fileBuffer = await decryptData(fileEncrypted, fileEncryptedIv, dataKey);
+    const chunks: ArrayBuffer[] = [];
+    let offset = 0;

+    while (offset < fileEncrypted.byteLength) {
+      const nextOffset = Math.min(offset + encryptedChunkSize, fileEncrypted.byteLength);
+      chunks.push(await decryptChunk(fileEncrypted.slice(offset, nextOffset), dataKey));
+      offset = nextOffset;
+    }
+
+    const fileBuffer = concatenateBuffers(...chunks).buffer;
    state.status = "decrypted";
    state.result = fileBuffer;
    return fileBuffer;
@@ -79,7 +88,7 @@ const decryptFile = limitFunction(
  { concurrency: 4 },
 );

-export const downloadFile = async (id: number, fileEncryptedIv: string, dataKey: CryptoKey) => {
+export const downloadFile = async (id: number, dataKey: CryptoKey, isLegacy: boolean) => {
  downloadingFiles.push({
    id,
    status: "download-pending",
@@ -87,7 +96,13 @@ export const downloadFile = async (id: number, fileEncryptedIv: string, dataKey:
  const state = downloadingFiles.at(-1)!;

  try {
-    return await decryptFile(state, await requestFileDownload(state, id), fileEncryptedIv, dataKey);
+    const fileEncrypted = await requestFileDownload(state, id);
+    return await decryptFile(
+      state,
+      fileEncrypted,
+      isLegacy ? fileEncrypted.byteLength : ENCRYPTED_CHUNK_SIZE,
+      dataKey,
+    );
  } catch (e) {
    state.status = "error";
    throw e;
--- a/src/lib/modules/file/thumbnail.ts
+++ b/src/lib/modules/file/thumbnail.ts
@@ -1,11 +1,10 @@
 import { LRUCache } from "lru-cache";
 import { writable, type Writable } from "svelte/store";
 import { browser } from "$app/environment";
-import { decryptData } from "$lib/modules/crypto";
+import { decryptChunk } from "$lib/modules/crypto";
 import type { SummarizedFileInfo } from "$lib/modules/filesystem";
 import { readFile, writeFile, deleteFile, deleteDirectory } from "$lib/modules/opfs";
 import { getThumbnailUrl } from "$lib/modules/thumbnail";
-import { isTRPCClientError, trpc } from "$trpc/client";

 const loadedThumbnails = new LRUCache<number, Writable<string>>({ max: 100 });
 const loadingThumbnails = new Map<number, Writable<string | undefined>>();
@@ -18,25 +17,13 @@ const fetchFromOpfs = async (fileId: number) => {
 };

 const fetchFromServer = async (fileId: number, dataKey: CryptoKey) => {
-  try {
-    const [thumbnailEncrypted, { contentIv: thumbnailEncryptedIv }] = await Promise.all([
-      fetch(`/api/file/${fileId}/thumbnail/download`),
-      trpc().file.thumbnail.query({ id: fileId }),
-    ]);
-    const thumbnailBuffer = await decryptData(
-      await thumbnailEncrypted.arrayBuffer(),
-      thumbnailEncryptedIv,
-      dataKey,
-    );
+  const res = await fetch(`/api/file/${fileId}/thumbnail/download`);
+  if (!res.ok) return null;
+
+  const thumbnailBuffer = await decryptChunk(await res.arrayBuffer(), dataKey);

  void writeFile(`/thumbnail/file/${fileId}`, thumbnailBuffer);
  return getThumbnailUrl(thumbnailBuffer);
-  } catch (e) {
-    if (isTRPCClientError(e) && e.data?.code === "NOT_FOUND") {
-      return null;
-    }
-    throw e;
-  }
 };

 export const getFileThumbnail = (file: SummarizedFileInfo) => {
--- a/src/lib/modules/file/upload.svelte.ts
+++ b/src/lib/modules/file/upload.svelte.ts
@@ -1,23 +1,12 @@
-import axios from "axios";
 import ExifReader from "exifreader";
 import { limitFunction } from "p-limit";
-import {
-  encodeToBase64,
-  generateDataKey,
-  wrapDataKey,
-  encryptData,
-  encryptString,
-  digestMessage,
-  signMessageHmac,
-} from "$lib/modules/crypto";
-import { Scheduler } from "$lib/modules/scheduler";
+import { CHUNK_SIZE } from "$lib/constants";
+import { encodeToBase64, generateDataKey, wrapDataKey, encryptString } from "$lib/modules/crypto";
+import { signMessageHmac } from "$lib/modules/crypto";
 import { generateThumbnail } from "$lib/modules/thumbnail";
-import type {
-  FileThumbnailUploadRequest,
-  FileUploadRequest,
-  FileUploadResponse,
-} from "$lib/server/schemas";
+import { uploadBlob } from "$lib/modules/upload";
 import type { MasterKey, HmacSecret } from "$lib/stores";
+import { Scheduler } from "$lib/utils";
 import { trpc } from "$trpc/client";

 export interface FileUploadState {
@@ -42,7 +31,7 @@ export type LiveFileUploadState = FileUploadState & {
 };

 const scheduler = new Scheduler<
-  { fileId: number; fileBuffer: ArrayBuffer; thumbnailBuffer?: ArrayBuffer } | undefined
+  { fileId: number; fileBuffer?: ArrayBuffer; thumbnailBuffer?: ArrayBuffer } | undefined
 >();
 let uploadingFiles: FileUploadState[] = $state([]);

@@ -61,16 +50,21 @@ export const clearUploadedFiles = () => {
 };

 const requestDuplicateFileScan = limitFunction(
-  async (file: File, hmacSecret: HmacSecret, onDuplicate: () => Promise<boolean>) => {
-    const fileBuffer = await file.arrayBuffer();
-    const fileSigned = encodeToBase64(await signMessageHmac(fileBuffer, hmacSecret.secret));
+  async (
+    state: FileUploadState,
+    file: File,
+    hmacSecret: HmacSecret,
+    onDuplicate: () => Promise<boolean>,
+  ) => {
+    state.status = "encryption-pending";

+    const fileSigned = encodeToBase64(await signMessageHmac(file, hmacSecret.secret));
    const files = await trpc().file.listByHash.query({
      hskVersion: hmacSecret.version,
      contentHmac: fileSigned,
    });
    if (files.length === 0 || (await onDuplicate())) {
-      return { fileBuffer, fileSigned };
+      return { fileSigned };
    } else {
      return {};
    }
@@ -110,74 +104,98 @@ const extractExifDateTime = (fileBuffer: ArrayBuffer) => {
  return new Date(utcDate - offsetMs);
 };

-const encryptFile = limitFunction(
-  async (state: FileUploadState, file: File, fileBuffer: ArrayBuffer, masterKey: MasterKey) => {
-    state.status = "encrypting";
-
-    const fileType = getFileType(file);
-
-    let createdAt;
-    if (fileType.startsWith("image/")) {
-      createdAt = extractExifDateTime(fileBuffer);
+interface FileMetadata {
+  parentId: "root" | number;
+  name: string;
+  createdAt?: Date;
+  lastModifiedAt: Date;
 }

+const requestFileMetadataEncryption = limitFunction(
+  async (
+    state: FileUploadState,
+    file: Blob,
+    fileMetadata: FileMetadata,
+    masterKey: MasterKey,
+    hmacSecret: HmacSecret,
+  ) => {
+    state.status = "encrypting";
+
    const { dataKey, dataKeyVersion } = await generateDataKey();
    const dataKeyWrapped = await wrapDataKey(dataKey, masterKey.key);

-    const fileEncrypted = await encryptData(fileBuffer, dataKey);
-    const fileEncryptedHash = encodeToBase64(await digestMessage(fileEncrypted.ciphertext));
+    const [nameEncrypted, createdAtEncrypted, lastModifiedAtEncrypted, thumbnailBuffer] =
+      await Promise.all([
+        encryptString(fileMetadata.name, dataKey),
+        fileMetadata.createdAt &&
+          encryptString(fileMetadata.createdAt.getTime().toString(), dataKey),
+        encryptString(fileMetadata.lastModifiedAt.getTime().toString(), dataKey),
+        generateThumbnail(file).then((blob) => blob?.arrayBuffer()),
+      ]);

-    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 thumbnail = await generateThumbnail(fileBuffer, fileType);
-    const thumbnailBuffer = await thumbnail?.arrayBuffer();
-    const thumbnailEncrypted = thumbnailBuffer && (await encryptData(thumbnailBuffer, dataKey));
+    const { uploadId } = await trpc().upload.startFileUpload.mutate({
+      chunks: Math.ceil(file.size / CHUNK_SIZE),
+      parent: fileMetadata.parentId,
+      mekVersion: masterKey.version,
+      dek: dataKeyWrapped,
+      dekVersion: dataKeyVersion,
+      hskVersion: hmacSecret.version,
+      contentType: file.type,
+      name: nameEncrypted.ciphertext,
+      nameIv: nameEncrypted.iv,
+      createdAt: createdAtEncrypted?.ciphertext,
+      createdAtIv: createdAtEncrypted?.iv,
+      lastModifiedAt: lastModifiedAtEncrypted.ciphertext,
+      lastModifiedAtIv: lastModifiedAtEncrypted.iv,
+    });

    state.status = "upload-pending";
-
-    return {
-      dataKeyWrapped,
-      dataKeyVersion,
-      fileType,
-      fileEncrypted,
-      fileEncryptedHash,
-      nameEncrypted,
-      createdAtEncrypted,
-      lastModifiedAtEncrypted,
-      thumbnail: thumbnailEncrypted && { plaintext: thumbnailBuffer, ...thumbnailEncrypted },
-    };
+    return { uploadId, thumbnailBuffer, dataKey, dataKeyVersion };
  },
  { concurrency: 4 },
 );

 const requestFileUpload = limitFunction(
-  async (state: FileUploadState, form: FormData, thumbnailForm: FormData | null) => {
+  async (
+    state: FileUploadState,
+    uploadId: string,
+    file: Blob,
+    fileSigned: string,
+    thumbnailBuffer: ArrayBuffer | undefined,
+    dataKey: CryptoKey,
+    dataKeyVersion: Date,
+  ) => {
    state.status = "uploading";

-    const res = await axios.post("/api/file/upload", form, {
-      onUploadProgress: ({ progress, rate, estimated }) => {
-        state.progress = progress;
-        state.rate = rate;
-        state.estimated = estimated;
+    await uploadBlob(uploadId, file, dataKey, {
+      onProgress(s) {
+        state.progress = s.progress;
+        state.rate = s.rate;
      },
    });
-    const { file }: FileUploadResponse = res.data;

-    if (thumbnailForm) {
+    const { file: fileId } = await trpc().upload.completeFileUpload.mutate({
+      uploadId,
+      contentHmac: fileSigned,
+    });
+
+    if (thumbnailBuffer) {
      try {
-        await axios.post(`/api/file/${file}/thumbnail/upload`, thumbnailForm);
+        const { uploadId } = await trpc().upload.startFileThumbnailUpload.mutate({
+          file: fileId,
+          dekVersion: dataKeyVersion,
+        });
+
+        await uploadBlob(uploadId, new Blob([thumbnailBuffer]), dataKey);
+
+        await trpc().upload.completeFileThumbnailUpload.mutate({ uploadId });
      } catch (e) {
-        // TODO
        console.error(e);
      }
    }

    state.status = "uploaded";
-
-    return { fileId: file };
+    return { fileId };
  },
  { concurrency: 1 },
 );
@@ -185,8 +203,8 @@ const requestFileUpload = limitFunction(
 export const uploadFile = async (
  file: File,
  parentId: "root" | number,
-  hmacSecret: HmacSecret,
  masterKey: MasterKey,
+  hmacSecret: HmacSecret,
  onDuplicate: () => Promise<boolean>,
 ) => {
  uploadingFiles.push({
@@ -197,70 +215,44 @@ export const uploadFile = async (
  const state = uploadingFiles.at(-1)!;

  return await scheduler.schedule(file.size, async () => {
-    state.status = "encryption-pending";
-
    try {
-      const { fileBuffer, fileSigned } = await requestDuplicateFileScan(
-        file,
-        hmacSecret,
-        onDuplicate,
-      );
-      if (!fileBuffer || !fileSigned) {
+      const { fileSigned } = await requestDuplicateFileScan(state, file, hmacSecret, onDuplicate);
+
+      if (!fileSigned) {
        state.status = "canceled";
        uploadingFiles = uploadingFiles.filter((file) => file !== state);
-        return undefined;
+        return;
      }

-      const {
-        dataKeyWrapped,
+      let fileBuffer;
+      const fileType = getFileType(file);
+      const fileMetadata: FileMetadata = {
+        parentId,
+        name: file.name,
+        lastModifiedAt: new Date(file.lastModified),
+      };
+
+      if (fileType.startsWith("image/")) {
+        fileBuffer = await file.arrayBuffer();
+        fileMetadata.createdAt = extractExifDateTime(fileBuffer);
+      }
+
+      const blob = new Blob([file], { type: fileType });
+
+      const { uploadId, thumbnailBuffer, dataKey, dataKeyVersion } =
+        await requestFileMetadataEncryption(state, blob, fileMetadata, masterKey, hmacSecret);
+
+      const { fileId } = await requestFileUpload(
+        state,
+        uploadId,
+        blob,
+        fileSigned,
+        thumbnailBuffer,
+        dataKey,
        dataKeyVersion,
-        fileType,
-        fileEncrypted,
-        fileEncryptedHash,
-        nameEncrypted,
-        createdAtEncrypted,
-        lastModifiedAtEncrypted,
-        thumbnail,
-      } = await encryptFile(state, file, fileBuffer, masterKey);
-
-      const form = new FormData();
-      form.set(
-        "metadata",
-        JSON.stringify({
-          parent: 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,
-        } satisfies FileUploadRequest),
      );
-      form.set("content", new Blob([fileEncrypted.ciphertext]));
-      form.set("checksum", fileEncryptedHash);

-      let thumbnailForm = null;
-      if (thumbnail) {
-        thumbnailForm = new FormData();
-        thumbnailForm.set(
-          "metadata",
-          JSON.stringify({
-            dekVersion: dataKeyVersion.toISOString(),
-            contentIv: thumbnail.iv,
-          } satisfies FileThumbnailUploadRequest),
-        );
-        thumbnailForm.set("content", new Blob([thumbnail.ciphertext]));
-      }
-
-      const { fileId } = await requestFileUpload(state, form, thumbnailForm);
-      return { fileId, fileBuffer, thumbnailBuffer: thumbnail?.plaintext };
+      return { fileId, fileBuffer, thumbnailBuffer };
    } catch (e) {
      state.status = "error";
      throw e;
--- a/src/lib/modules/filesystem/file.ts
+++ b/src/lib/modules/filesystem/file.ts
@@ -47,10 +47,10 @@ const cache = new FilesystemCache<number, MaybeFileInfo>({

      return storeToIndexedDB({
        id,
+        isLegacy: file.isLegacy,
        parentId: file.parent,
        dataKey: metadata.dataKey,
        contentType: file.contentType,
-        contentIv: file.contentIv,
        name: metadata.name,
        createdAt: metadata.createdAt,
        lastModifiedAt: metadata.lastModifiedAt,
@@ -116,9 +116,9 @@ const cache = new FilesystemCache<number, MaybeFileInfo>({
        return {
          id,
          exists: true as const,
+          isLegacy: metadataRaw.isLegacy,
          parentId: metadataRaw.parent,
          contentType: metadataRaw.contentType,
-          contentIv: metadataRaw.contentIv,
          categories,
          ...metadata,
        };
--- a/src/lib/modules/filesystem/types.ts
+++ b/src/lib/modules/filesystem/types.ts
@@ -28,10 +28,10 @@ export type SubDirectoryInfo = Omit<LocalDirectoryInfo, "subDirectories" | "file

 export interface FileInfo {
  id: number;
+  isLegacy?: boolean;
  parentId: DirectoryId;
  dataKey?: DataKey;
  contentType: string;
-  contentIv?: string;
  name: string;
  createdAt?: Date;
  lastModifiedAt: Date;
@@ -42,7 +42,7 @@ export type MaybeFileInfo =
  | (FileInfo & { exists: true })
  | ({ id: number; exists: false } & AllUndefined<Omit<FileInfo, "id">>);

-export type SummarizedFileInfo = Omit<FileInfo, "contentIv" | "categories">;
+export type SummarizedFileInfo = Omit<FileInfo, "categories">;
 export type CategoryFileInfo = SummarizedFileInfo & { isRecursive: boolean };

 interface LocalCategoryInfo {
--- a/src/lib/modules/http.ts
+++ b/src/lib/modules/http.ts
@@ -0,0 +1,22 @@
+export const parseRangeHeader = (value: string | null) => {
+  if (!value) return undefined;
+
+  const firstRange = value.split(",")[0]!.trim();
+  const parts = firstRange.replace(/bytes=/, "").split("-");
+  return {
+    start: parts[0] ? parseInt(parts[0], 10) : undefined,
+    end: parts[1] ? parseInt(parts[1], 10) : undefined,
+  };
+};
+
+export const getContentRangeHeader = (range?: { start: number; end: number; total: number }) => {
+  return range && { "Content-Range": `bytes ${range.start}-${range.end}/${range.total}` };
+};
+
+export const parseContentDigestHeader = (value: string | null) => {
+  if (!value) return undefined;
+
+  const firstDigest = value.split(",")[0]!.trim();
+  const match = firstDigest.match(/^sha-256=:([A-Za-z0-9+/=]+):$/);
+  return match?.[1];
+};
--- a/src/lib/modules/key.ts
+++ b/src/lib/modules/key.ts
@@ -2,7 +2,7 @@ import { z } from "zod";
 import { storeClientKey } from "$lib/indexedDB";
 import type { ClientKeys } from "$lib/stores";

-const serializedClientKeysSchema = z.intersection(
+const SerializedClientKeysSchema = z.intersection(
  z.object({
    generator: z.literal("ArkVault"),
    exportedAt: z.iso.datetime(),
@@ -16,7 +16,7 @@ const serializedClientKeysSchema = z.intersection(
  }),
 );

-type SerializedClientKeys = z.infer<typeof serializedClientKeysSchema>;
+type SerializedClientKeys = z.infer<typeof SerializedClientKeysSchema>;

 type DeserializedClientKeys = {
  encryptKeyBase64: string;
@@ -43,7 +43,7 @@ export const serializeClientKeys = ({
 };

 export const deserializeClientKeys = (serialized: string) => {
-  const zodRes = serializedClientKeysSchema.safeParse(JSON.parse(serialized));
+  const zodRes = SerializedClientKeysSchema.safeParse(JSON.parse(serialized));
  if (zodRes.success) {
    return {
      encryptKeyBase64: zodRes.data.encryptKey,
--- a/src/lib/modules/opfs.ts
+++ b/src/lib/modules/opfs.ts
@@ -1,13 +1,5 @@
-let rootHandle: FileSystemDirectoryHandle | null = null;
-
-export const prepareOpfs = async () => {
-  rootHandle = await navigator.storage.getDirectory();
-};
-
 const getFileHandle = async (path: string, create = true) => {
-  if (!rootHandle) {
-    throw new Error("OPFS not prepared");
-  } else if (path[0] !== "/") {
+  if (path[0] !== "/") {
    throw new Error("Path must be absolute");
  }

@@ -17,7 +9,7 @@ const getFileHandle = async (path: string, create = true) => {
  }

  try {
-    let directoryHandle = rootHandle;
+    let directoryHandle = await navigator.storage.getDirectory();
    for (const part of parts.slice(0, -1)) {
      if (!part) continue;
      directoryHandle = await directoryHandle.getDirectoryHandle(part, { create });
@@ -34,12 +26,15 @@ const getFileHandle = async (path: string, create = true) => {
  }
 };

-export const readFile = async (path: string) => {
+export const getFile = async (path: string) => {
  const { fileHandle } = await getFileHandle(path, false);
  if (!fileHandle) return null;

-  const file = await fileHandle.getFile();
-  return await file.arrayBuffer();
+  return await fileHandle.getFile();
+};
+
+export const readFile = async (path: string) => {
+  return (await getFile(path))?.arrayBuffer() ?? null;
 };

 export const writeFile = async (path: string, data: ArrayBuffer) => {
@@ -61,9 +56,7 @@ export const deleteFile = async (path: string) => {
 };

 const getDirectoryHandle = async (path: string) => {
-  if (!rootHandle) {
-    throw new Error("OPFS not prepared");
-  } else if (path[0] !== "/") {
+  if (path[0] !== "/") {
    throw new Error("Path must be absolute");
  }

@@ -73,7 +66,7 @@ const getDirectoryHandle = async (path: string) => {
  }

  try {
-    let directoryHandle = rootHandle;
+    let directoryHandle = await navigator.storage.getDirectory();
    let parentHandle;
    for (const part of parts.slice(1)) {
      if (!part) continue;
--- a/src/lib/modules/thumbnail.ts
+++ b/src/lib/modules/thumbnail.ts
@@ -52,7 +52,6 @@ const generateImageThumbnail = (imageUrl: string) => {
        .catch(reject);
    };
    image.onerror = reject;
-
    image.src = imageUrl;
  });
 };
@@ -85,31 +84,27 @@ const generateVideoThumbnail = (videoUrl: string, time = 0) => {
  });
 };

-export const generateThumbnail = async (fileBuffer: ArrayBuffer, fileType: string) => {
+export const generateThumbnail = async (blob: Blob) => {
  let url;
  try {
-    if (fileType.startsWith("image/")) {
-      const fileBlob = new Blob([fileBuffer], { type: fileType });
-      url = URL.createObjectURL(fileBlob);
-
+    if (blob.type.startsWith("image/")) {
+      url = URL.createObjectURL(blob);
      try {
        return await generateImageThumbnail(url);
      } catch {
        URL.revokeObjectURL(url);
        url = undefined;

-        if (fileType === "image/heic") {
+        if (blob.type === "image/heic") {
          const { default: heic2any } = await import("heic2any");
-          url = URL.createObjectURL(
-            (await heic2any({ blob: fileBlob, toType: "image/png" })) as Blob,
-          );
+          url = URL.createObjectURL((await heic2any({ blob, toType: "image/png" })) as Blob);
          return await generateImageThumbnail(url);
        } else {
          return null;
        }
      }
-    } else if (fileType.startsWith("video/")) {
-      url = URL.createObjectURL(new Blob([fileBuffer], { type: fileType }));
+    } else if (blob.type.startsWith("video/")) {
+      url = URL.createObjectURL(blob);
      return await generateVideoThumbnail(url);
    }
    return null;
--- a/src/lib/modules/upload.ts
+++ b/src/lib/modules/upload.ts
@@ -0,0 +1,183 @@
+import axios from "axios";
+import pLimit from "p-limit";
+import { ENCRYPTION_OVERHEAD, CHUNK_SIZE } from "$lib/constants";
+import { encryptChunk, digestMessage, encodeToBase64 } from "$lib/modules/crypto";
+import { BoundedQueue } from "$lib/utils";
+
+interface UploadStats {
+  progress: number;
+  rate: number;
+}
+
+interface EncryptedChunk {
+  index: number;
+  data: ArrayBuffer;
+  hash: string;
+}
+
+const createSpeedMeter = (timeWindow = 3000, minInterval = 200, warmupPeriod = 500) => {
+  const samples: { t: number; b: number }[] = [];
+  let lastSpeed = 0;
+  let startTime: number | null = null;
+
+  return (bytesNow?: number) => {
+    if (bytesNow === undefined) return lastSpeed;
+
+    const now = performance.now();
+
+    // Initialize start time on first call
+    if (startTime === null) {
+      startTime = now;
+    }
+
+    // Check if enough time has passed since the last sample
+    const lastSample = samples[samples.length - 1];
+    if (lastSample && now - lastSample.t < minInterval) {
+      return lastSpeed;
+    }
+
+    samples.push({ t: now, b: bytesNow });
+
+    // Remove old samples outside the time window
+    const cutoff = now - timeWindow;
+    while (samples.length > 2 && samples[0]!.t < cutoff) samples.shift();
+
+    // Need at least 2 samples to calculate speed
+    if (samples.length < 2) {
+      return lastSpeed;
+    }
+
+    const first = samples[0]!;
+    const dt = now - first.t;
+    const db = bytesNow - first.b;
+
+    if (dt >= minInterval) {
+      const instantSpeed = (db / dt) * 1000;
+      // Apply EMA for smoother speed transitions
+      const alpha = 0.3;
+      const rawSpeed =
+        lastSpeed === 0 ? instantSpeed : alpha * instantSpeed + (1 - alpha) * lastSpeed;
+
+      // Apply warmup ramp to prevent initial overestimation
+      const elapsed = now - startTime;
+      const warmupWeight = Math.min(1, elapsed / warmupPeriod);
+      lastSpeed = rawSpeed * warmupWeight;
+    }
+
+    return lastSpeed;
+  };
+};
+
+const encryptChunkData = async (
+  chunk: Blob,
+  dataKey: CryptoKey,
+): Promise<{ data: ArrayBuffer; hash: string }> => {
+  const encrypted = await encryptChunk(await chunk.arrayBuffer(), dataKey);
+  const hash = encodeToBase64(await digestMessage(encrypted));
+  return { data: encrypted, hash };
+};
+
+const uploadEncryptedChunk = async (
+  uploadId: string,
+  chunkIndex: number,
+  encrypted: ArrayBuffer,
+  hash: string,
+  onChunkProgress: (chunkIndex: number, loaded: number) => void,
+) => {
+  await axios.post(`/api/upload/${uploadId}/chunks/${chunkIndex + 1}`, encrypted, {
+    headers: {
+      "Content-Type": "application/octet-stream",
+      "Content-Digest": `sha-256=:${hash}:`,
+    },
+    onUploadProgress(e) {
+      onChunkProgress(chunkIndex, e.loaded ?? 0);
+    },
+  });
+
+  onChunkProgress(chunkIndex, encrypted.byteLength);
+};
+
+export const uploadBlob = async (
+  uploadId: string,
+  blob: Blob,
+  dataKey: CryptoKey,
+  options?: { concurrency?: number; onProgress?: (s: UploadStats) => void },
+) => {
+  const onProgress = options?.onProgress;
+  const networkConcurrency = options?.concurrency ?? 4;
+  const maxQueueSize = 8;
+
+  const totalChunks = Math.ceil(blob.size / CHUNK_SIZE);
+  const totalBytes = blob.size + totalChunks * ENCRYPTION_OVERHEAD;
+
+  const uploadedByChunk = new Array<number>(totalChunks).fill(0);
+  const speedMeter = createSpeedMeter(3000, 200);
+
+  const emit = () => {
+    if (!onProgress) return;
+
+    const uploadedBytes = uploadedByChunk.reduce((a, b) => a + b, 0);
+    const rate = speedMeter(uploadedBytes);
+    const progress = Math.min(1, uploadedBytes / totalBytes);
+
+    onProgress({ progress, rate });
+  };
+
+  const onChunkProgress = (idx: number, loaded: number) => {
+    uploadedByChunk[idx] = loaded;
+    emit();
+  };
+
+  const queue = new BoundedQueue<EncryptedChunk>(maxQueueSize);
+  let encryptionError: Error | null = null;
+
+  // Producer: encrypt chunks and push to queue
+  const encryptionProducer = async () => {
+    try {
+      for (let i = 0; i < totalChunks; i++) {
+        const chunk = blob.slice(i * CHUNK_SIZE, (i + 1) * CHUNK_SIZE);
+        const { data, hash } = await encryptChunkData(chunk, dataKey);
+        await queue.push({ index: i, data, hash });
+      }
+    } catch (e) {
+      encryptionError = e instanceof Error ? e : new Error(String(e));
+    } finally {
+      queue.close();
+    }
+  };
+
+  // Consumer: upload chunks from queue with concurrency limit
+  const uploadConsumer = async () => {
+    const limit = pLimit(networkConcurrency);
+    const activeTasks = new Set<Promise<void>>();
+
+    while (true) {
+      const item = await queue.pop();
+      if (item === null) break;
+      if (encryptionError) throw encryptionError;
+
+      const task = limit(async () => {
+        try {
+          await uploadEncryptedChunk(uploadId, item.index, item.data, item.hash, onChunkProgress);
+        } finally {
+          // @ts-ignore
+          item.data = null;
+        }
+      });
+
+      activeTasks.add(task);
+      task.finally(() => activeTasks.delete(task));
+
+      if (activeTasks.size >= networkConcurrency) {
+        await Promise.race(activeTasks);
+      }
+    }
+
+    await Promise.all(activeTasks);
+  };
+
+  // Run producer and consumer concurrently
+  await Promise.all([encryptionProducer(), uploadConsumer()]);
+
+  onProgress?.({ progress: 1, rate: speedMeter() });
+};
--- a/src/lib/schemas/filesystem.ts
+++ b/src/lib/schemas/filesystem.ts
@@ -0,0 +1,4 @@
+import { z } from "zod";
+
+export const DirectoryIdSchema = z.union([z.literal("root"), z.int().positive()]);
+export const CategoryIdSchema = z.union([z.literal("root"), z.int().positive()]);
--- a/src/lib/schemas/index.ts
+++ b/src/lib/schemas/index.ts
@@ -0,0 +1 @@
+export * from "./filesystem";
--- a/src/lib/server/db/error.ts
+++ b/src/lib/server/db/error.ts
@@ -9,6 +9,7 @@ type IntegrityErrorMessages =
  // File
  | "Directory not found"
  | "File not found"
+  | "File is not legacy"
  | "File not found in category"
  | "File already added to category"
  | "Invalid DEK version"
--- a/src/lib/server/db/file.ts
+++ b/src/lib/server/db/file.ts
@@ -15,8 +15,6 @@ interface Directory {
  encName: Ciphertext;
 }

-export type NewDirectory = Omit<Directory, "id">;
-
 interface File {
  id: number;
  parentId: DirectoryId;
@@ -28,15 +26,13 @@ interface File {
  hskVersion: number | null;
  contentHmac: string | null;
  contentType: string;
-  encContentIv: string;
+  encContentIv: string | null;
  encContentHash: string;
  encName: Ciphertext;
  encCreatedAt: Ciphertext | null;
  encLastModifiedAt: Ciphertext;
 }

-export type NewFile = Omit<File, "id">;
-
 interface FileCategory {
  id: number;
  parentId: CategoryId;
@@ -46,7 +42,7 @@ interface FileCategory {
  encName: Ciphertext;
 }

-export const registerDirectory = async (params: NewDirectory) => {
+export const registerDirectory = async (params: Omit<Directory, "id">) => {
  await db.transaction().execute(async (trx) => {
    const mek = await trx
      .selectFrom("master_encryption_key")
@@ -214,38 +210,11 @@ export const unregisterDirectory = async (userId: number, directoryId: number) =
    });
 };

-export const registerFile = async (params: NewFile) => {
+export const registerFile = async (trx: typeof db, params: Omit<File, "id">) => {
  if ((params.hskVersion && !params.contentHmac) || (!params.hskVersion && params.contentHmac)) {
    throw new Error("Invalid arguments");
  }

-  return await db.transaction().execute(async (trx) => {
-    const mek = await trx
-      .selectFrom("master_encryption_key")
-      .select("version")
-      .where("user_id", "=", params.userId)
-      .where("state", "=", "active")
-      .limit(1)
-      .forUpdate()
-      .executeTakeFirst();
-    if (mek?.version !== params.mekVersion) {
-      throw new IntegrityError("Inactive MEK version");
-    }
-
-    if (params.hskVersion) {
-      const hsk = await trx
-        .selectFrom("hmac_secret_key")
-        .select("version")
-        .where("user_id", "=", params.userId)
-        .where("state", "=", "active")
-        .limit(1)
-        .forUpdate()
-        .executeTakeFirst();
-      if (hsk?.version !== params.hskVersion) {
-        throw new IntegrityError("Inactive HSK version");
-      }
-    }
-
  const { fileId } = await trx
    .insertInto("file")
    .values({
@@ -276,7 +245,6 @@ export const registerFile = async (params: NewFile) => {
    })
    .execute();
  return { id: fileId };
-  });
 };

 export const getAllFilesByParent = async (userId: number, parentId: DirectoryId) => {
@@ -366,6 +334,16 @@ export const getAllFileIds = async (userId: number) => {
  return files.map(({ id }) => id);
 };

+export const getLegacyFileIds = async (userId: number) => {
+  const files = await db
+    .selectFrom("file")
+    .select("id")
+    .where("user_id", "=", userId)
+    .where("encrypted_content_iv", "is not", null)
+    .execute();
+  return files.map(({ id }) => id);
+};
+
 export const getAllFileIdsByContentHmac = async (
  userId: number,
  hskVersion: number,
@@ -514,6 +492,51 @@ export const unregisterFile = async (userId: number, fileId: number) => {
  });
 };

+export const migrateFileContent = async (
+  trx: typeof db,
+  userId: number,
+  fileId: number,
+  newPath: string,
+  dekVersion: Date,
+  encContentHash: string,
+) => {
+  const file = await trx
+    .selectFrom("file")
+    .select(["path", "data_encryption_key_version", "encrypted_content_iv"])
+    .where("id", "=", fileId)
+    .where("user_id", "=", userId)
+    .limit(1)
+    .forUpdate()
+    .executeTakeFirst();
+  if (!file) {
+    throw new IntegrityError("File not found");
+  } else if (file.data_encryption_key_version.getTime() !== dekVersion.getTime()) {
+    throw new IntegrityError("Invalid DEK version");
+  } else if (!file.encrypted_content_iv) {
+    throw new IntegrityError("File is not legacy");
+  }
+
+  await trx
+    .updateTable("file")
+    .set({
+      path: newPath,
+      encrypted_content_iv: null,
+      encrypted_content_hash: encContentHash,
+    })
+    .where("id", "=", fileId)
+    .where("user_id", "=", userId)
+    .execute();
+  await trx
+    .insertInto("file_log")
+    .values({
+      file_id: fileId,
+      timestamp: new Date(),
+      action: "migrate",
+    })
+    .execute();
+  return { oldPath: file.path };
+};
+
 export const addFileToCategory = async (fileId: number, categoryId: number) => {
  await db.transaction().execute(async (trx) => {
    try {
--- a/src/lib/server/db/index.ts
+++ b/src/lib/server/db/index.ts
@@ -5,6 +5,7 @@ export * as HskRepo from "./hsk";
 export * as MediaRepo from "./media";
 export * as MekRepo from "./mek";
 export * as SessionRepo from "./session";
+export * as UploadRepo from "./upload";
 export * as UserRepo from "./user";

 export * from "./error";
--- a/src/lib/server/db/media.ts
+++ b/src/lib/server/db/media.ts
@@ -6,7 +6,7 @@ interface Thumbnail {
  id: number;
  path: string;
  updatedAt: Date;
-  encContentIv: string;
+  encContentIv: string | null;
 }

 interface FileThumbnail extends Thumbnail {
@@ -14,13 +14,13 @@ interface FileThumbnail extends Thumbnail {
 }

 export const updateFileThumbnail = async (
+  trx: typeof db,
  userId: number,
  fileId: number,
  dekVersion: Date,
  path: string,
-  encContentIv: string,
+  encContentIv: string | null,
 ) => {
-  return await db.transaction().execute(async (trx) => {
  const file = await trx
    .selectFrom("file")
    .select("data_encryption_key_version")
@@ -61,7 +61,6 @@ export const updateFileThumbnail = async (
    )
    .execute();
  return thumbnail?.oldPath ?? null;
-  });
 };

 export const getFileThumbnail = async (userId: number, fileId: number) => {
--- a/src/lib/server/db/migrations/1768062380-AddChunkedUpload.ts
+++ b/src/lib/server/db/migrations/1768062380-AddChunkedUpload.ts
@@ -0,0 +1,74 @@
+import { Kysely, sql } from "kysely";
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export const up = async (db: Kysely<any>) => {
+  // file.ts
+  await db.schema
+    .alterTable("file")
+    .alterColumn("encrypted_content_iv", (col) => col.dropNotNull())
+    .execute();
+
+  // media.ts
+  await db.schema
+    .alterTable("thumbnail")
+    .alterColumn("encrypted_content_iv", (col) => col.dropNotNull())
+    .execute();
+
+  // upload.ts
+  await db.schema
+    .createTable("upload_session")
+    .addColumn("id", "uuid", (col) => col.primaryKey())
+    .addColumn("type", "text", (col) => col.notNull())
+    .addColumn("user_id", "integer", (col) => col.references("user.id").notNull())
+    .addColumn("path", "text", (col) => col.notNull())
+    .addColumn("bitmap", "bytea", (col) => col.notNull())
+    .addColumn("total_chunks", "integer", (col) => col.notNull())
+    .addColumn("uploaded_chunks", "integer", (col) =>
+      col
+        .generatedAlwaysAs(sql`bit_count(bitmap)`)
+        .stored()
+        .notNull(),
+    )
+    .addColumn("expires_at", "timestamp(3)", (col) => col.notNull())
+    .addColumn("parent_id", "integer", (col) => col.references("directory.id"))
+    .addColumn("master_encryption_key_version", "integer")
+    .addColumn("encrypted_data_encryption_key", "text")
+    .addColumn("data_encryption_key_version", "timestamp(3)")
+    .addColumn("hmac_secret_key_version", "integer")
+    .addColumn("content_type", "text")
+    .addColumn("encrypted_name", "json")
+    .addColumn("encrypted_created_at", "json")
+    .addColumn("encrypted_last_modified_at", "json")
+    .addColumn("file_id", "integer", (col) => col.references("file.id"))
+    .addForeignKeyConstraint(
+      "upload_session_fk01",
+      ["user_id", "master_encryption_key_version"],
+      "master_encryption_key",
+      ["user_id", "version"],
+    )
+    .addForeignKeyConstraint(
+      "upload_session_fk02",
+      ["user_id", "hmac_secret_key_version"],
+      "hmac_secret_key",
+      ["user_id", "version"],
+    )
+    .addCheckConstraint(
+      "upload_session_ck01",
+      sql`length(bitmap) = ceil(total_chunks / 8.0)::integer`,
+    )
+    .addCheckConstraint("upload_session_ck02", sql`uploaded_chunks <= total_chunks`)
+    .execute();
+};
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export const down = async (db: Kysely<any>) => {
+  await db.schema.dropTable("upload_session").execute();
+  await db.schema
+    .alterTable("thumbnail")
+    .alterColumn("encrypted_content_iv", (col) => col.setNotNull())
+    .execute();
+  await db.schema
+    .alterTable("file")
+    .alterColumn("encrypted_content_iv", (col) => col.setNotNull())
+    .execute();
+};
--- a/src/lib/server/db/migrations/index.ts
+++ b/src/lib/server/db/migrations/index.ts
@@ -1,9 +1,11 @@
 import * as Initial1737357000 from "./1737357000-Initial";
 import * as AddFileCategory1737422340 from "./1737422340-AddFileCategory";
 import * as AddThumbnail1738409340 from "./1738409340-AddThumbnail";
+import * as AddChunkedUpload1768062380 from "./1768062380-AddChunkedUpload";

 export default {
  "1737357000-Initial": Initial1737357000,
  "1737422340-AddFileCategory": AddFileCategory1737422340,
  "1738409340-AddThumbnail": AddThumbnail1738409340,
+  "1768062380-AddChunkedUpload": AddChunkedUpload1768062380,
 };
--- a/src/lib/server/db/schema/category.ts
+++ b/src/lib/server/db/schema/category.ts
@@ -1,5 +1,5 @@
 import type { Generated } from "kysely";
-import type { Ciphertext } from "./util";
+import type { Ciphertext } from "./utils";

 interface CategoryTable {
  id: Generated<number>;
--- a/src/lib/server/db/schema/file.ts
+++ b/src/lib/server/db/schema/file.ts
@@ -1,5 +1,5 @@
 import type { ColumnType, Generated } from "kysely";
-import type { Ciphertext } from "./util";
+import type { Ciphertext } from "./utils";

 interface DirectoryTable {
  id: Generated<number>;
@@ -30,7 +30,7 @@ interface FileTable {
  hmac_secret_key_version: number | null;
  content_hmac: string | null; // Base64
  content_type: string;
-  encrypted_content_iv: string; // Base64
+  encrypted_content_iv: string | null; // Base64
  encrypted_content_hash: string; // Base64
  encrypted_name: Ciphertext;
  encrypted_created_at: Ciphertext | null;
@@ -41,7 +41,7 @@ interface FileLogTable {
  id: Generated<number>;
  file_id: number;
  timestamp: ColumnType<Date, Date, never>;
-  action: "create" | "rename" | "add-to-category" | "remove-from-category";
+  action: "create" | "rename" | "migrate" | "add-to-category" | "remove-from-category";
  new_name: Ciphertext | null;
  category_id: number | null;
 }
--- a/src/lib/server/db/schema/index.ts
+++ b/src/lib/server/db/schema/index.ts
@@ -5,8 +5,9 @@ export * from "./hsk";
 export * from "./media";
 export * from "./mek";
 export * from "./session";
+export * from "./upload";
 export * from "./user";
-export * from "./util";
+export * from "./utils";

 // eslint-disable-next-line @typescript-eslint/no-empty-object-type
 export interface Database {}
--- a/src/lib/server/db/schema/media.ts
+++ b/src/lib/server/db/schema/media.ts
@@ -7,7 +7,7 @@ interface ThumbnailTable {
  category_id: number | null;
  path: string;
  updated_at: Date;
-  encrypted_content_iv: string; // Base64
+  encrypted_content_iv: string | null; // Base64
 }

 declare module "./index" {
--- a/src/lib/server/db/schema/upload.ts
+++ b/src/lib/server/db/schema/upload.ts
@@ -0,0 +1,30 @@
+import type { Generated } from "kysely";
+import type { Ciphertext } from "./utils";
+
+interface UploadSessionTable {
+  id: string;
+  type: "file" | "thumbnail" | "migration";
+  user_id: number;
+  path: string;
+  bitmap: Buffer;
+  total_chunks: number;
+  uploaded_chunks: Generated<number>;
+  expires_at: Date;
+
+  parent_id: number | null;
+  master_encryption_key_version: number | null;
+  encrypted_data_encryption_key: string | null; // Base64
+  data_encryption_key_version: Date | null;
+  hmac_secret_key_version: number | null;
+  content_type: string | null;
+  encrypted_name: Ciphertext | null;
+  encrypted_created_at: Ciphertext | null;
+  encrypted_last_modified_at: Ciphertext | null;
+  file_id: number | null;
+}
+
+declare module "./index" {
+  interface Database {
+    upload_session: UploadSessionTable;
+  }
+}
--- a/src/lib/server/db/schema/utils.ts
+++ b/src/lib/server/db/schema/utils.ts
--- a/src/lib/server/db/upload.ts
+++ b/src/lib/server/db/upload.ts
@@ -0,0 +1,192 @@
+import { sql } from "kysely";
+import { IntegrityError } from "./error";
+import db from "./kysely";
+import type { Ciphertext } from "./schema";
+
+interface BaseUploadSession {
+  id: string;
+  userId: number;
+  path: string;
+  bitmap: Buffer;
+  totalChunks: number;
+  uploadedChunks: number;
+  expiresAt: Date;
+}
+
+interface FileUploadSession extends BaseUploadSession {
+  type: "file";
+  parentId: DirectoryId;
+  mekVersion: number;
+  encDek: string;
+  dekVersion: Date;
+  hskVersion: number | null;
+  contentType: string;
+  encName: Ciphertext;
+  encCreatedAt: Ciphertext | null;
+  encLastModifiedAt: Ciphertext;
+}
+
+interface ThumbnailOrMigrationUploadSession extends BaseUploadSession {
+  type: "thumbnail" | "migration";
+  fileId: number;
+  dekVersion: Date;
+}
+
+export const createFileUploadSession = async (
+  params: Omit<FileUploadSession, "type" | "bitmap" | "uploadedChunks">,
+) => {
+  await db.transaction().execute(async (trx) => {
+    const mek = await trx
+      .selectFrom("master_encryption_key")
+      .select("version")
+      .where("user_id", "=", params.userId)
+      .where("state", "=", "active")
+      .limit(1)
+      .forUpdate()
+      .executeTakeFirst();
+    if (mek?.version !== params.mekVersion) {
+      throw new IntegrityError("Inactive MEK version");
+    }
+
+    if (params.hskVersion) {
+      const hsk = await trx
+        .selectFrom("hmac_secret_key")
+        .select("version")
+        .where("user_id", "=", params.userId)
+        .where("state", "=", "active")
+        .limit(1)
+        .forUpdate()
+        .executeTakeFirst();
+      if (hsk?.version !== params.hskVersion) {
+        throw new IntegrityError("Inactive HSK version");
+      }
+    }
+
+    await trx
+      .insertInto("upload_session")
+      .values({
+        id: params.id,
+        type: "file",
+        user_id: params.userId,
+        path: params.path,
+        bitmap: Buffer.alloc(Math.ceil(params.totalChunks / 8)),
+        total_chunks: params.totalChunks,
+        expires_at: params.expiresAt,
+        parent_id: params.parentId !== "root" ? params.parentId : null,
+        master_encryption_key_version: params.mekVersion,
+        encrypted_data_encryption_key: params.encDek,
+        data_encryption_key_version: params.dekVersion,
+        hmac_secret_key_version: params.hskVersion,
+        content_type: params.contentType,
+        encrypted_name: params.encName,
+        encrypted_created_at: params.encCreatedAt,
+        encrypted_last_modified_at: params.encLastModifiedAt,
+      })
+      .execute();
+  });
+};
+
+export const createThumbnailOrMigrationUploadSession = async (
+  params: Omit<ThumbnailOrMigrationUploadSession, "bitmap" | "uploadedChunks">,
+) => {
+  await db.transaction().execute(async (trx) => {
+    const file = await trx
+      .selectFrom("file")
+      .select("data_encryption_key_version")
+      .where("id", "=", params.fileId)
+      .where("user_id", "=", params.userId)
+      .limit(1)
+      .forUpdate()
+      .executeTakeFirst();
+    if (!file) {
+      throw new IntegrityError("File not found");
+    } else if (file.data_encryption_key_version.getTime() !== params.dekVersion.getTime()) {
+      throw new IntegrityError("Invalid DEK version");
+    }
+
+    await trx
+      .insertInto("upload_session")
+      .values({
+        id: params.id,
+        type: params.type,
+        user_id: params.userId,
+        path: params.path,
+        bitmap: Buffer.alloc(Math.ceil(params.totalChunks / 8)),
+        total_chunks: params.totalChunks,
+        expires_at: params.expiresAt,
+        file_id: params.fileId,
+        data_encryption_key_version: params.dekVersion,
+      })
+      .execute();
+  });
+};
+
+export const getUploadSession = async (sessionId: string, userId: number) => {
+  const session = await db
+    .selectFrom("upload_session")
+    .selectAll()
+    .where("id", "=", sessionId)
+    .where("user_id", "=", userId)
+    .where("expires_at", ">", new Date())
+    .limit(1)
+    .executeTakeFirst();
+  if (!session) {
+    return null;
+  } else if (session.type === "file") {
+    return {
+      type: "file",
+      id: session.id,
+      userId: session.user_id,
+      path: session.path,
+      bitmap: session.bitmap,
+      totalChunks: session.total_chunks,
+      uploadedChunks: session.uploaded_chunks,
+      expiresAt: session.expires_at,
+      parentId: session.parent_id ?? "root",
+      mekVersion: session.master_encryption_key_version!,
+      encDek: session.encrypted_data_encryption_key!,
+      dekVersion: session.data_encryption_key_version!,
+      hskVersion: session.hmac_secret_key_version,
+      contentType: session.content_type!,
+      encName: session.encrypted_name!,
+      encCreatedAt: session.encrypted_created_at,
+      encLastModifiedAt: session.encrypted_last_modified_at!,
+    } satisfies FileUploadSession;
+  } else {
+    return {
+      type: session.type,
+      id: session.id,
+      userId: session.user_id,
+      path: session.path,
+      bitmap: session.bitmap,
+      totalChunks: session.total_chunks,
+      uploadedChunks: session.uploaded_chunks,
+      expiresAt: session.expires_at,
+      fileId: session.file_id!,
+      dekVersion: session.data_encryption_key_version!,
+    } satisfies ThumbnailOrMigrationUploadSession;
+  }
+};
+
+export const markChunkAsUploaded = async (sessionId: string, chunkIndex: number) => {
+  await db
+    .updateTable("upload_session")
+    .set({
+      bitmap: sql`set_bit(${sql.ref("bitmap")}, ${chunkIndex - 1}, 1)`,
+    })
+    .where("id", "=", sessionId)
+    .execute();
+};
+
+export const deleteUploadSession = async (trx: typeof db, sessionId: string) => {
+  await trx.deleteFrom("upload_session").where("id", "=", sessionId).execute();
+};
+
+export const cleanupExpiredUploadSessions = async () => {
+  const sessions = await db
+    .deleteFrom("upload_session")
+    .where("expires_at", "<=", new Date())
+    .returning("path")
+    .execute();
+  return sessions.map(({ path }) => path);
+};
--- a/src/lib/server/loadenv.ts
+++ b/src/lib/server/loadenv.ts
@@ -26,4 +26,5 @@ export default {
  },
  libraryPath: env.LIBRARY_PATH || "library",
  thumbnailsPath: env.THUMBNAILS_PATH || "thumbnails",
+  uploadsPath: env.UPLOADS_PATH || "uploads",
 };
--- a/src/lib/server/modules/filesystem.ts
+++ b/src/lib/server/modules/filesystem.ts
@@ -1,4 +1,10 @@
-import { unlink } from "fs/promises";
+import { rm, unlink } from "fs/promises";
+
+export const safeRecursiveRm = async (path: string | null | undefined) => {
+  if (path) {
+    await rm(path, { recursive: true }).catch(console.error);
+  }
+};

 export const safeUnlink = async (path: string | null | undefined) => {
  if (path) {
--- a/src/lib/server/schemas/category.ts
+++ b/src/lib/server/schemas/category.ts
@@ -1,3 +0,0 @@
-import { z } from "zod";
-
-export const categoryIdSchema = z.union([z.literal("root"), z.int().positive()]);
--- a/src/lib/server/schemas/directory.ts
+++ b/src/lib/server/schemas/directory.ts
@@ -1,3 +0,0 @@
-import { z } from "zod";
-
-export const directoryIdSchema = z.union([z.literal("root"), z.int().positive()]);
--- a/src/lib/server/schemas/file.ts
+++ b/src/lib/server/schemas/file.ts
@@ -1,36 +0,0 @@
-import mime from "mime";
-import { z } from "zod";
-import { directoryIdSchema } from "./directory";
-
-export const fileThumbnailUploadRequest = z.object({
-  dekVersion: z.iso.datetime(),
-  contentIv: z.base64().nonempty(),
-});
-export type FileThumbnailUploadRequest = z.input<typeof fileThumbnailUploadRequest>;
-
-export const fileUploadRequest = z.object({
-  parent: directoryIdSchema,
-  mekVersion: z.int().positive(),
-  dek: z.base64().nonempty(),
-  dekVersion: z.iso.datetime(),
-  hskVersion: z.int().positive(),
-  contentHmac: z.base64().nonempty(),
-  contentType: z
-    .string()
-    .trim()
-    .nonempty()
-    .refine((value) => mime.getExtension(value) !== null), // MIME type
-  contentIv: z.base64().nonempty(),
-  name: z.base64().nonempty(),
-  nameIv: z.base64().nonempty(),
-  createdAt: z.base64().nonempty().optional(),
-  createdAtIv: z.base64().nonempty().optional(),
-  lastModifiedAt: z.base64().nonempty(),
-  lastModifiedAtIv: z.base64().nonempty(),
-});
-export type FileUploadRequest = z.input<typeof fileUploadRequest>;
-
-export const fileUploadResponse = z.object({
-  file: z.int().positive(),
-});
-export type FileUploadResponse = z.output<typeof fileUploadResponse>;
--- a/src/lib/server/schemas/index.ts
+++ b/src/lib/server/schemas/index.ts
@@ -1,3 +0,0 @@
-export * from "./category";
-export * from "./directory";
-export * from "./file";
--- a/src/lib/server/services/file.ts
+++ b/src/lib/server/services/file.ts
@@ -1,126 +1,74 @@
 import { error } from "@sveltejs/kit";
-import { createHash } from "crypto";
-import { createReadStream, createWriteStream } from "fs";
-import { mkdir, stat } from "fs/promises";
-import { dirname } from "path";
+import { createReadStream } from "fs";
+import { stat } from "fs/promises";
 import { Readable } from "stream";
-import { pipeline } from "stream/promises";
-import { v4 as uuidv4 } from "uuid";
-import { FileRepo, MediaRepo, IntegrityError } from "$lib/server/db";
-import env from "$lib/server/loadenv";
-import { safeUnlink } from "$lib/server/modules/filesystem";
+import { FileRepo, MediaRepo } from "$lib/server/db";

-export const getFileStream = async (userId: number, fileId: number) => {
+const createEncContentStream = async (
+  path: string,
+  iv?: Buffer,
+  range?: { start?: number; end?: number },
+) => {
+  const { size: fileSize } = await stat(path);
+  const ivSize = iv?.byteLength ?? 0;
+  const totalSize = fileSize + ivSize;
+
+  const start = range?.start ?? 0;
+  const end = range?.end ?? totalSize - 1;
+  if (start > end || start < 0 || end >= totalSize) {
+    error(416, "Invalid range");
+  }
+
+  return {
+    encContentStream: Readable.toWeb(
+      Readable.from(
+        (async function* () {
+          if (start < ivSize) {
+            yield iv!.subarray(start, Math.min(end + 1, ivSize));
+          }
+          if (end >= ivSize) {
+            yield* createReadStream(path, {
+              start: Math.max(0, start - ivSize),
+              end: end - ivSize,
+            });
+          }
+        })(),
+      ),
+    ),
+    range: { start, end, total: totalSize },
+  };
+};
+
+export const getFileStream = async (
+  userId: number,
+  fileId: number,
+  range?: { start?: number; end?: number },
+) => {
  const file = await FileRepo.getFile(userId, fileId);
  if (!file) {
    error(404, "Invalid file id");
  }

-  const { size } = await stat(file.path);
-  return {
-    encContentStream: Readable.toWeb(createReadStream(file.path)),
-    encContentSize: size,
-  };
+  return createEncContentStream(
+    file.path,
+    file.encContentIv ? Buffer.from(file.encContentIv, "base64") : undefined,
+    range,
+  );
 };

-export const getFileThumbnailStream = async (userId: number, fileId: number) => {
+export const getFileThumbnailStream = async (
+  userId: number,
+  fileId: number,
+  range?: { start?: number; end?: number },
+) => {
  const thumbnail = await MediaRepo.getFileThumbnail(userId, fileId);
  if (!thumbnail) {
    error(404, "File or its thumbnail not found");
  }

-  const { size } = await stat(thumbnail.path);
-  return {
-    encContentStream: Readable.toWeb(createReadStream(thumbnail.path)),
-    encContentSize: size,
-  };
-};
-
-export const uploadFileThumbnail = async (
-  userId: number,
-  fileId: number,
-  dekVersion: Date,
-  encContentIv: string,
-  encContentStream: Readable,
-) => {
-  const path = `${env.thumbnailsPath}/${userId}/${uuidv4()}`;
-  await mkdir(dirname(path), { recursive: true });
-
-  try {
-    await pipeline(encContentStream, createWriteStream(path, { flags: "wx", mode: 0o600 }));
-
-    const oldPath = await MediaRepo.updateFileThumbnail(
-      userId,
-      fileId,
-      dekVersion,
-      path,
-      encContentIv,
+  return createEncContentStream(
+    thumbnail.path,
+    thumbnail.encContentIv ? Buffer.from(thumbnail.encContentIv, "base64") : undefined,
+    range,
  );
-    safeUnlink(oldPath); // Intended
-  } catch (e) {
-    await safeUnlink(path);
-
-    if (e instanceof IntegrityError) {
-      if (e.message === "File not found") {
-        error(404, "File not found");
-      } else if (e.message === "Invalid DEK version") {
-        error(400, "Mismatched DEK version");
-      }
-    }
-    throw e;
-  }
-};
-
-export const uploadFile = async (
-  params: Omit<FileRepo.NewFile, "path" | "encContentHash">,
-  encContentStream: Readable,
-  encContentHash: Promise<string>,
-) => {
-  const oneDayAgo = new Date(Date.now() - 24 * 60 * 60 * 1000);
-  const oneMinuteLater = new Date(Date.now() + 60 * 1000);
-  if (params.dekVersion <= oneDayAgo || params.dekVersion >= oneMinuteLater) {
-    error(400, "Invalid DEK version");
-  }
-
-  const path = `${env.libraryPath}/${params.userId}/${uuidv4()}`;
-  await mkdir(dirname(path), { recursive: true });
-
-  try {
-    const hashStream = createHash("sha256");
-    const [, hash] = await Promise.all([
-      pipeline(
-        encContentStream,
-        async function* (source) {
-          for await (const chunk of source) {
-            hashStream.update(chunk);
-            yield chunk;
-          }
-        },
-        createWriteStream(path, { flags: "wx", mode: 0o600 }),
-      ),
-      encContentHash,
-    ]);
-    if (hashStream.digest("base64") !== hash) {
-      throw new Error("Invalid checksum");
-    }
-
-    const { id: fileId } = await FileRepo.registerFile({
-      ...params,
-      path,
-      encContentHash: hash,
-    });
-    return { fileId };
-  } catch (e) {
-    await safeUnlink(path);
-
-    if (e instanceof IntegrityError && e.message === "Inactive MEK version") {
-      error(400, "Invalid MEK version");
-    } else if (
-      e instanceof Error &&
-      (e.message === "Invalid request body" || e.message === "Invalid checksum")
-    ) {
-      error(400, "Invalid request body");
-    }
-    throw e;
-  }
 };
--- a/src/lib/server/services/upload.ts
+++ b/src/lib/server/services/upload.ts
@@ -0,0 +1,88 @@
+import { error } from "@sveltejs/kit";
+import { createHash } from "crypto";
+import { createWriteStream } from "fs";
+import { Readable } from "stream";
+import { ENCRYPTION_OVERHEAD, ENCRYPTED_CHUNK_SIZE } from "$lib/constants";
+import { UploadRepo } from "$lib/server/db";
+import { safeRecursiveRm, safeUnlink } from "$lib/server/modules/filesystem";
+
+const chunkLocks = new Set<string>();
+
+const isChunkUploaded = (bitmap: Buffer, chunkIndex: number) => {
+  chunkIndex -= 1;
+  const byte = bitmap[Math.floor(chunkIndex / 8)];
+  return !!byte && (byte & (1 << (chunkIndex % 8))) !== 0; // Postgres sucks
+};
+
+export const uploadChunk = async (
+  userId: number,
+  sessionId: string,
+  chunkIndex: number,
+  encChunkStream: Readable,
+  encChunkHash: string,
+) => {
+  const lockKey = `${sessionId}/${chunkIndex}`;
+  if (chunkLocks.has(lockKey)) {
+    error(409, "Chunk upload already in progress");
+  } else {
+    chunkLocks.add(lockKey);
+  }
+
+  let filePath;
+
+  try {
+    const session = await UploadRepo.getUploadSession(sessionId, userId);
+    if (!session) {
+      error(404, "Invalid upload id");
+    } else if (chunkIndex > session.totalChunks) {
+      error(400, "Invalid chunk index");
+    } else if (isChunkUploaded(session.bitmap, chunkIndex)) {
+      error(409, "Chunk already uploaded");
+    }
+
+    const isLastChunk = chunkIndex === session.totalChunks;
+    filePath = `${session.path}/${chunkIndex}`;
+
+    const hashStream = createHash("sha256");
+    const writeStream = createWriteStream(filePath, { flags: "wx", mode: 0o600 });
+    let writtenBytes = 0;
+
+    for await (const chunk of encChunkStream) {
+      hashStream.update(chunk);
+      writeStream.write(chunk);
+      writtenBytes += chunk.length;
+    }
+
+    await new Promise<void>((resolve, reject) => {
+      writeStream.end((e: any) => (e ? reject(e) : resolve()));
+    });
+
+    if (hashStream.digest("base64") !== encChunkHash) {
+      throw new Error("Invalid checksum");
+    } else if (
+      (!isLastChunk && writtenBytes !== ENCRYPTED_CHUNK_SIZE) ||
+      (isLastChunk && (writtenBytes <= ENCRYPTION_OVERHEAD || writtenBytes > ENCRYPTED_CHUNK_SIZE))
+    ) {
+      throw new Error("Invalid chunk size");
+    }
+
+    await UploadRepo.markChunkAsUploaded(sessionId, chunkIndex);
+  } catch (e) {
+    await safeUnlink(filePath);
+
+    if (
+      e instanceof Error &&
+      (e.message === "Invalid checksum" || e.message === "Invalid chunk size")
+    ) {
+      error(400, "Invalid request body");
+    }
+    throw e;
+  } finally {
+    chunkLocks.delete(lockKey);
+  }
+};
+
+export const cleanupExpiredUploadSessions = async () => {
+  const paths = await UploadRepo.cleanupExpiredUploadSessions();
+  await Promise.all(paths.map(safeRecursiveRm));
+};
--- a/src/lib/serviceWorker/client.ts
+++ b/src/lib/serviceWorker/client.ts
@@ -0,0 +1,39 @@
+import { DECRYPTED_FILE_URL_PREFIX } from "$lib/constants";
+import type { FileMetadata, ServiceWorkerMessage, ServiceWorkerResponse } from "./types";
+
+const PREPARE_TIMEOUT_MS = 5000;
+
+const getServiceWorker = async () => {
+  const registration = await navigator.serviceWorker.ready;
+  const sw = registration.active;
+  if (!sw) {
+    throw new Error("Service worker not activated");
+  }
+  return sw;
+};
+
+export const prepareFileDecryption = async (id: number, metadata: FileMetadata) => {
+  const sw = await getServiceWorker();
+  return new Promise<void>((resolve, reject) => {
+    const timeout = setTimeout(
+      () => reject(new Error("Service worker timeout")),
+      PREPARE_TIMEOUT_MS,
+    );
+    const handler = (event: MessageEvent<ServiceWorkerResponse>) => {
+      if (event.data.type === "decryption-ready" && event.data.fileId === id) {
+        clearTimeout(timeout);
+        navigator.serviceWorker.removeEventListener("message", handler);
+        resolve();
+      }
+    };
+    navigator.serviceWorker.addEventListener("message", handler);
+
+    sw.postMessage({
+      type: "decryption-prepare",
+      fileId: id,
+      ...metadata,
+    } satisfies ServiceWorkerMessage);
+  });
+};
+
+export const getDecryptedFileUrl = (id: number) => `${DECRYPTED_FILE_URL_PREFIX}${id}`;
--- a/src/lib/serviceWorker/index.ts
+++ b/src/lib/serviceWorker/index.ts
@@ -0,0 +1,2 @@
+export * from "./client";
+export * from "./types";
--- a/src/lib/serviceWorker/types.ts
+++ b/src/lib/serviceWorker/types.ts
@@ -0,0 +1,19 @@
+export interface FileMetadata {
+  isLegacy: boolean;
+  dataKey: CryptoKey;
+  encContentSize: number;
+  contentType: string;
+}
+
+export interface DecryptionPrepareMessage extends FileMetadata {
+  type: "decryption-prepare";
+  fileId: number;
+}
+
+export interface DecryptionReadyMessage {
+  type: "decryption-ready";
+  fileId: number;
+}
+
+export type ServiceWorkerMessage = DecryptionPrepareMessage;
+export type ServiceWorkerResponse = DecryptionReadyMessage;
--- a/src/lib/services/file.ts
+++ b/src/lib/services/file.ts
@@ -6,38 +6,42 @@ import {
  downloadFile,
  deleteFileThumbnailCache,
 } from "$lib/modules/file";
-import type { FileThumbnailUploadRequest } from "$lib/server/schemas";
+import { uploadBlob } from "$lib/modules/upload";
 import { trpc } from "$trpc/client";

 export const requestFileDownload = async (
  fileId: number,
-  fileEncryptedIv: string,
  dataKey: CryptoKey,
+  isLegacy: boolean,
 ) => {
  const cache = await getFileCache(fileId);
  if (cache) return cache;

-  const fileBuffer = await downloadFile(fileId, fileEncryptedIv, dataKey);
+  const fileBuffer = await downloadFile(fileId, dataKey, isLegacy);
  storeFileCache(fileId, fileBuffer); // Intended
  return fileBuffer;
 };

 export const requestFileThumbnailUpload = async (
  fileId: number,
+  thumbnail: Blob,
+  dataKey: CryptoKey,
  dataKeyVersion: Date,
-  thumbnailEncrypted: { ciphertext: ArrayBuffer; iv: string },
 ) => {
-  const form = new FormData();
-  form.set(
-    "metadata",
-    JSON.stringify({
-      dekVersion: dataKeyVersion.toISOString(),
-      contentIv: thumbnailEncrypted.iv,
-    } satisfies FileThumbnailUploadRequest),
-  );
-  form.set("content", new Blob([thumbnailEncrypted.ciphertext]));
+  try {
+    const { uploadId } = await trpc().upload.startFileThumbnailUpload.mutate({
+      file: fileId,
+      dekVersion: dataKeyVersion,
+    });

-  return await fetch(`/api/file/${fileId}/thumbnail/upload`, { method: "POST", body: form });
+    await uploadBlob(uploadId, thumbnail, dataKey);
+
+    await trpc().upload.completeFileThumbnailUpload.mutate({ uploadId });
+    return true;
+  } catch {
+    // TODO: Error Handling
+    return false;
+  }
 };

 export const requestDeletedFilesCleanup = async () => {
--- a/src/lib/utils/concurrency/BoundedQueue.ts
+++ b/src/lib/utils/concurrency/BoundedQueue.ts
@@ -0,0 +1,44 @@
+export class BoundedQueue<T> {
+  private isClosed = false;
+  private reservedCount = 0;
+  private items: T[] = [];
+
+  private waitersNotFull: (() => void)[] = [];
+  private waitersNotEmpty: (() => void)[] = [];
+
+  constructor(private readonly maxSize: number) {}
+
+  async push(item: T) {
+    if (this.isClosed) {
+      throw new Error("Queue closed");
+    }
+
+    while (this.reservedCount >= this.maxSize) {
+      await new Promise<void>((resolve) => this.waitersNotFull.push(resolve));
+      if (this.isClosed) throw new Error("Queue closed");
+    }
+
+    this.reservedCount++;
+    this.items.push(item);
+    this.waitersNotEmpty.shift()?.();
+  }
+
+  async pop() {
+    while (this.items.length === 0) {
+      if (this.isClosed) return null;
+      await new Promise<void>((resolve) => this.waitersNotEmpty.push(resolve));
+    }
+
+    const item = this.items.shift()!;
+    this.reservedCount--;
+    this.waitersNotFull.shift()?.();
+
+    return item;
+  }
+
+  close() {
+    this.isClosed = true;
+    while (this.waitersNotEmpty.length > 0) this.waitersNotEmpty.shift()!();
+    while (this.waitersNotFull.length > 0) this.waitersNotFull.shift()!();
+  }
+}
--- a/src/lib/utils/concurrency/HybridPromise.ts
+++ b/src/lib/utils/concurrency/HybridPromise.ts
--- a/src/lib/utils/concurrency/Scheduler.ts
+++ b/src/lib/utils/concurrency/Scheduler.ts
--- a/src/lib/utils/concurrency/index.ts
+++ b/src/lib/utils/concurrency/index.ts
@@ -0,0 +1,3 @@
+export * from "./BoundedQueue";
+export * from "./HybridPromise";
+export * from "./Scheduler";
--- a/src/lib/utils/index.ts
+++ b/src/lib/utils/index.ts
@@ -1,4 +1,4 @@
+export * from "./concurrency";
 export * from "./format";
 export * from "./gotoStateful";
-export * from "./HybridPromise";
 export * from "./sort";
--- a/src/params/thumbnail.ts
+++ b/src/params/thumbnail.ts
@@ -0,0 +1,5 @@
+import type { ParamMatcher } from "@sveltejs/kit";
+
+export const match: ParamMatcher = (param) => {
+  return param === "thumbnail";
+};
--- a/src/routes/(fullscreen)/file/[id]/+page.svelte
+++ b/src/routes/(fullscreen)/file/[id]/+page.svelte
@@ -5,7 +5,7 @@
  import { page } from "$app/state";
  import { FullscreenDiv } from "$lib/components/atoms";
  import { Categories, IconEntryButton, TopBar } from "$lib/components/molecules";
-  import { getFileInfo, type FileInfo, type MaybeFileInfo } from "$lib/modules/filesystem";
+  import { getFileInfo, type MaybeFileInfo } from "$lib/modules/filesystem";
  import { captureVideoThumbnail } from "$lib/modules/thumbnail";
  import { getFileDownloadState } from "$lib/modules/file";
  import { masterKeyStore } from "$lib/stores";
@@ -17,6 +17,7 @@
    requestFileDownload,
    requestThumbnailUpload,
    requestFileAdditionToCategory,
+    requestVideoStream,
  } from "./service";
  import TopBarMenu from "./TopBarMenu.svelte";

@@ -37,6 +38,7 @@
  let viewerType: "image" | "video" | undefined = $state();
  let fileBlob: Blob | undefined = $state();
  let fileBlobUrl: string | undefined = $state();
+  let videoStreamUrl: string | undefined = $state();
  let videoElement: HTMLVideoElement | undefined = $state();

  const updateViewer = async (buffer: ArrayBuffer, contentType: string) => {
@@ -95,7 +97,19 @@
      untrack(() => {
        if (!downloadState && !isDownloadRequested) {
          isDownloadRequested = true;
-          requestFileDownload(data.id, info!.contentIv!, info!.dataKey!.key).then(
+
+          if (viewerType === "video" && !info!.isLegacy) {
+            requestVideoStream(data.id, info!.dataKey!.key, contentType).then((streamUrl) => {
+              if (streamUrl) {
+                videoStreamUrl = streamUrl;
+              } else {
+                requestFileDownload(data.id, info!.dataKey!.key, info!.isLegacy!).then((buffer) =>
+                  updateViewer(buffer, contentType),
+                );
+              }
+            });
+          } else {
+            requestFileDownload(data.id, info!.dataKey!.key, info!.isLegacy!).then(
              async (buffer) => {
                const blob = await updateViewer(buffer, contentType);
                if (!viewerType) {
@@ -104,13 +118,16 @@
              },
            );
          }
+        }
      });
    }
  });

  $effect(() => {
    if (info?.exists && downloadState?.status === "decrypted") {
-      untrack(() => !isDownloadRequested && updateViewer(downloadState.result!, info!.contentIv!));
+      untrack(
+        () => !isDownloadRequested && updateViewer(downloadState.result!, info!.contentType!),
+      );
    }
  });

@@ -137,6 +154,7 @@
        ? info?.parentId
        : undefined}
      {fileBlob}
+      downloadUrl={videoStreamUrl}
      filename={info?.name}
    />
  </div>
@@ -159,9 +177,10 @@
            {@render viewerLoading("이미지를 불러오고 있어요.")}
          {/if}
        {:else if viewerType === "video"}
-          {#if fileBlobUrl}
+          {#if videoStreamUrl || fileBlobUrl}
            <div class="flex flex-col space-y-2">
-              <video bind:this={videoElement} src={fileBlobUrl} controls muted></video>
+              <video bind:this={videoElement} src={videoStreamUrl ?? fileBlobUrl} controls muted
+              ></video>
              <IconEntryButton
                icon={IconCamera}
                onclick={() => updateThumbnail(info?.dataKey?.key!, info?.dataKey?.version!)}
--- a/src/routes/(fullscreen)/file/[id]/TopBarMenu.svelte
+++ b/src/routes/(fullscreen)/file/[id]/TopBarMenu.svelte
@@ -10,17 +10,29 @@

  interface Props {
    directoryId?: "root" | number;
+    downloadUrl?: string;
    fileBlob?: Blob;
    filename?: string;
    isOpen: boolean;
  }

-  let { directoryId, fileBlob, filename, isOpen = $bindable() }: Props = $props();
+  let { directoryId, downloadUrl, fileBlob, filename, isOpen = $bindable() }: Props = $props();
+
+  const handleDownload = () => {
+    if (fileBlob && filename) {
+      FileSaver.saveAs(fileBlob, filename);
+    } else if (downloadUrl && filename) {
+      // Use streaming download via Content-Disposition header
+      const url = new URL(downloadUrl, window.location.origin);
+      url.searchParams.set("download", filename);
+      window.open(url.toString(), "_blank");
+    }
+  };
 </script>

 <svelte:window onclick={() => (isOpen = false)} />

-{#if isOpen && (directoryId || fileBlob)}
+{#if isOpen && (directoryId || downloadUrl || fileBlob)}
  <div
    class="absolute right-2 top-full z-20 space-y-1 rounded-lg bg-white px-1 py-2 shadow-2xl"
    transition:fly={{ y: -8, duration: 200 }}
@@ -49,10 +61,8 @@
          ),
        )}
      {/if}
-      {#if fileBlob}
-        {@render menuButton(IconCloudDownload, "다운로드", () => {
-          FileSaver.saveAs(fileBlob, filename);
-        })}
+      {#if fileBlob || downloadUrl}
+        {@render menuButton(IconCloudDownload, "다운로드", handleDownload)}
      {/if}
    </div>
  </div>
--- a/src/routes/(fullscreen)/file/[id]/service.ts
+++ b/src/routes/(fullscreen)/file/[id]/service.ts
@@ -1,23 +1,41 @@
-import { encryptData } from "$lib/modules/crypto";
 import { storeFileThumbnailCache } from "$lib/modules/file";
+import { prepareFileDecryption, getDecryptedFileUrl } from "$lib/serviceWorker";
 import { requestFileThumbnailUpload } from "$lib/services/file";
 import { trpc } from "$trpc/client";

 export { requestCategoryCreation, requestFileRemovalFromCategory } from "$lib/services/category";
 export { requestFileDownload } from "$lib/services/file";

+export const requestVideoStream = async (
+  fileId: number,
+  dataKey: CryptoKey,
+  contentType: string,
+) => {
+  const res = await fetch(`/api/file/${fileId}/download`, { method: "HEAD" });
+  if (!res.ok) return null;
+
+  const encContentSize = parseInt(res.headers.get("Content-Length") ?? "0", 10);
+  if (encContentSize <= 0) return null;
+
+  try {
+    await prepareFileDecryption(fileId, { isLegacy: false, dataKey, encContentSize, contentType });
+    return getDecryptedFileUrl(fileId);
+  } catch {
+    // TODO: Error Handling
+    return null;
+  }
+};
+
 export const requestThumbnailUpload = async (
  fileId: number,
  thumbnail: Blob,
  dataKey: CryptoKey,
  dataKeyVersion: Date,
 ) => {
-  const thumbnailBuffer = await thumbnail.arrayBuffer();
-  const thumbnailEncrypted = await encryptData(thumbnailBuffer, dataKey);
-  const res = await requestFileThumbnailUpload(fileId, dataKeyVersion, thumbnailEncrypted);
-  if (!res.ok) return false;
+  const res = await requestFileThumbnailUpload(fileId, thumbnail, dataKey, dataKeyVersion);
+  if (!res) return false;

-  storeFileThumbnailCache(fileId, thumbnailBuffer); // Intended
+  void thumbnail.arrayBuffer().then((buffer) => storeFileThumbnailCache(fileId, buffer));
  return true;
 };

--- a/src/routes/(fullscreen)/settings/migration/+page.server.ts
+++ b/src/routes/(fullscreen)/settings/migration/+page.server.ts
@@ -0,0 +1,7 @@
+import { createCaller } from "$trpc/router.server";
+import type { PageServerLoad } from "./$types";
+
+export const load: PageServerLoad = async (event) => {
+  const files = await createCaller(event).file.listLegacy();
+  return { files };
+};
--- a/src/routes/(fullscreen)/settings/migration/+page.svelte
+++ b/src/routes/(fullscreen)/settings/migration/+page.svelte
@@ -0,0 +1,79 @@
+<script lang="ts">
+  import { onMount } from "svelte";
+  import { goto } from "$app/navigation";
+  import { BottomDiv, Button, FullscreenDiv } from "$lib/components/atoms";
+  import { TopBar } from "$lib/components/molecules";
+  import { bulkGetFileInfo, type MaybeFileInfo } from "$lib/modules/filesystem";
+  import { masterKeyStore } from "$lib/stores";
+  import { sortEntries } from "$lib/utils";
+  import File from "./File.svelte";
+  import { getMigrationState, clearMigrationStates, requestFileMigration } from "./service.svelte";
+
+  let { data } = $props();
+
+  let fileInfos: MaybeFileInfo[] = $state([]);
+  let files = $derived(
+    fileInfos
+      .map((info) => ({
+        info,
+        state: getMigrationState(info.id),
+      }))
+      .filter((file) => file.state?.status !== "uploaded"),
+  );
+
+  const migrateAllFiles = () => {
+    files.forEach(({ info }) => {
+      if (info.exists) {
+        requestFileMigration(info);
+      }
+    });
+  };
+
+  onMount(async () => {
+    fileInfos = sortEntries(
+      Array.from((await bulkGetFileInfo(data.files, $masterKeyStore?.get(1)?.key!)).values()),
+    );
+  });
+
+  $effect(() => clearMigrationStates);
+</script>
+
+<svelte:head>
+  <title>암호화 마이그레이션</title>
+</svelte:head>
+
+<TopBar title="암호화 마이그레이션" />
+<FullscreenDiv>
+  {#if files.length > 0}
+    <div class="space-y-4 pb-4">
+      <p class="break-keep text-gray-800">
+        이전 버전의 ArkVault에서 업로드된 {files.length}개 파일을 다시 암호화할 수 있어요.
+      </p>
+      <div class="space-y-2">
+        {#each files as { info, state } (info.id)}
+          {#if info.exists}
+            <File
+              {info}
+              {state}
+              onclick={({ id }) => goto(`/file/${id}`)}
+              onMigrateClick={requestFileMigration}
+            />
+          {/if}
+        {/each}
+      </div>
+    </div>
+    <BottomDiv>
+      <Button onclick={migrateAllFiles} class="w-full">모두 다시 암호화하기</Button>
+    </BottomDiv>
+  {:else}
+    <div class="flex flex-grow items-center justify-center">
+      <p class="text-gray-500">
+        {#if data.files.length === 0}
+          마이그레이션할 파일이 없어요.
+        {:else}
+          파일 목록을 불러오고 있어요.
+        {/if}
+      </p>
+    </div>
+  {/if}
+</FullscreenDiv>
--- a/src/routes/(fullscreen)/settings/migration/File.svelte
+++ b/src/routes/(fullscreen)/settings/migration/File.svelte
@@ -0,0 +1,52 @@
+<script module lang="ts">
+  const subtexts = {
+    queued: "대기 중",
+    downloading: "다운로드하는 중",
+    "upload-pending": "업로드를 기다리는 중",
+    uploaded: "",
+    error: "실패",
+  } as const;
+</script>
+
+<script lang="ts">
+  import { ActionEntryButton } from "$lib/components/atoms";
+  import { DirectoryEntryLabel } from "$lib/components/molecules";
+  import type { FileInfo } from "$lib/modules/filesystem";
+  import { formatDateTime, formatNetworkSpeed } from "$lib/utils";
+  import type { MigrationState } from "./service.svelte";
+
+  import IconSync from "~icons/material-symbols/sync";
+
+  type FileInfoWithExists = FileInfo & { exists: true };
+
+  interface Props {
+    info: FileInfoWithExists;
+    onclick: (file: FileInfo) => void;
+    onMigrateClick: (file: FileInfoWithExists) => void;
+    state: MigrationState | undefined;
+  }
+
+  let { info, onclick, onMigrateClick, state }: Props = $props();
+
+  let subtext = $derived.by(() => {
+    if (!state) {
+      return formatDateTime(info.createdAt ?? info.lastModifiedAt);
+    }
+    if (state.status === "uploading") {
+      const progress = Math.floor((state.progress ?? 0) * 100);
+      const speed = formatNetworkSpeed((state.rate ?? 0) * 8);
+      return `전송됨 ${progress}% · ${speed}`;
+    }
+    return subtexts[state.status] ?? state.status;
+  });
+</script>
+
+<ActionEntryButton
+  class="h-14"
+  onclick={() => onclick(info)}
+  actionButtonIcon={!state || state.status === "error" ? IconSync : undefined}
+  onActionButtonClick={() => onMigrateClick(info)}
+  actionButtonClass="text-gray-800"
+>
+  <DirectoryEntryLabel type="file" name={info.name} {subtext} />
+</ActionEntryButton>
--- a/src/routes/(fullscreen)/settings/migration/service.svelte.ts
+++ b/src/routes/(fullscreen)/settings/migration/service.svelte.ts
@@ -0,0 +1,105 @@
+import { limitFunction } from "p-limit";
+import { SvelteMap } from "svelte/reactivity";
+import { CHUNK_SIZE } from "$lib/constants";
+import type { FileInfo } from "$lib/modules/filesystem";
+import { uploadBlob } from "$lib/modules/upload";
+import { requestFileDownload } from "$lib/services/file";
+import { Scheduler } from "$lib/utils";
+import { trpc } from "$trpc/client";
+
+export type MigrationStatus =
+  | "queued"
+  | "downloading"
+  | "upload-pending"
+  | "uploading"
+  | "uploaded"
+  | "error";
+
+export interface MigrationState {
+  status: MigrationStatus;
+  progress?: number;
+  rate?: number;
+}
+
+const scheduler = new Scheduler();
+const states = new SvelteMap<number, MigrationState>();
+
+const createState = (status: MigrationStatus): MigrationState => {
+  const state = $state({ status });
+  return state;
+};
+
+export const getMigrationState = (fileId: number) => {
+  return states.get(fileId);
+};
+
+export const clearMigrationStates = () => {
+  for (const [id, state] of states) {
+    if (state.status === "uploaded" || state.status === "error") {
+      states.delete(id);
+    }
+  }
+};
+
+const requestFileUpload = limitFunction(
+  async (
+    state: MigrationState,
+    fileId: number,
+    fileBuffer: ArrayBuffer,
+    dataKey: CryptoKey,
+    dataKeyVersion: Date,
+  ) => {
+    state.status = "uploading";
+
+    const { uploadId } = await trpc().upload.startMigrationUpload.mutate({
+      file: fileId,
+      chunks: Math.ceil(fileBuffer.byteLength / CHUNK_SIZE),
+      dekVersion: dataKeyVersion,
+    });
+
+    await uploadBlob(uploadId, new Blob([fileBuffer]), dataKey, {
+      onProgress(s) {
+        state.progress = s.progress;
+        state.rate = s.rate;
+      },
+    });
+
+    await trpc().upload.completeMigrationUpload.mutate({ uploadId });
+    state.status = "uploaded";
+  },
+  { concurrency: 1 },
+);
+
+export const requestFileMigration = async (fileInfo: FileInfo) => {
+  let state = states.get(fileInfo.id);
+  if (state) {
+    if (state.status !== "error") return;
+    state.status = "queued";
+    state.progress = undefined;
+    state.rate = undefined;
+  } else {
+    state = createState("queued");
+    states.set(fileInfo.id, state);
+  }
+
+  try {
+    const dataKey = fileInfo.dataKey;
+    if (!dataKey) {
+      throw new Error("Data key not available");
+    }
+
+    let fileBuffer: ArrayBuffer | undefined;
+
+    await scheduler.schedule(
+      async () => {
+        state.status = "downloading";
+        fileBuffer = await requestFileDownload(fileInfo.id, dataKey.key, true);
+        return fileBuffer.byteLength;
+      },
+      () => requestFileUpload(state, fileInfo.id, fileBuffer!, dataKey.key, dataKey.version),
+    );
+  } catch (e) {
+    state.status = "error";
+    throw e;
+  }
+};
--- a/src/routes/(fullscreen)/settings/thumbnail/File.svelte
+++ b/src/routes/(fullscreen)/settings/thumbnail/File.svelte
@@ -3,7 +3,6 @@
    queued: "대기 중",
    "generation-pending": "준비 중",
    generating: "생성하는 중",
-    "upload-pending": "업로드를 기다리는 중",
    uploading: "업로드하는 중",
    error: "실패",
  } as const;
--- a/src/routes/(fullscreen)/settings/thumbnail/service.ts
+++ b/src/routes/(fullscreen)/settings/thumbnail/service.ts
@@ -1,17 +1,15 @@
 import { limitFunction } from "p-limit";
 import { SvelteMap } from "svelte/reactivity";
-import { encryptData } from "$lib/modules/crypto";
 import { storeFileThumbnailCache } from "$lib/modules/file";
 import type { FileInfo } from "$lib/modules/filesystem";
-import { Scheduler } from "$lib/modules/scheduler";
-import { generateThumbnail as doGenerateThumbnail } from "$lib/modules/thumbnail";
+import { generateThumbnail } from "$lib/modules/thumbnail";
 import { requestFileDownload, requestFileThumbnailUpload } from "$lib/services/file";
+import { Scheduler } from "$lib/utils";

 export type GenerationStatus =
  | "queued"
  | "generation-pending"
  | "generating"
-  | "upload-pending"
  | "uploading"
  | "uploaded"
  | "error";
@@ -31,33 +29,27 @@ export const clearThumbnailGenerationStatuses = () => {
  }
 };

-const generateThumbnail = limitFunction(
-  async (fileId: number, fileBuffer: ArrayBuffer, fileType: string, dataKey: CryptoKey) => {
-    statuses.set(fileId, "generating");
-
-    const thumbnail = await doGenerateThumbnail(fileBuffer, fileType);
-    if (!thumbnail) return null;
-
-    const thumbnailBuffer = await thumbnail.arrayBuffer();
-    const thumbnailEncrypted = await encryptData(thumbnailBuffer, dataKey);
-    statuses.set(fileId, "upload-pending");
-    return { plaintext: thumbnailBuffer, ...thumbnailEncrypted };
-  },
-  { concurrency: 4 },
-);
-
 const requestThumbnailUpload = limitFunction(
-  async (
-    fileId: number,
-    dataKeyVersion: Date,
-    thumbnail: { plaintext: ArrayBuffer; ciphertext: ArrayBuffer; iv: string },
-  ) => {
-    statuses.set(fileId, "uploading");
+  async (fileInfo: FileInfo, fileBuffer: ArrayBuffer) => {
+    statuses.set(fileInfo.id, "generating");

-    const res = await requestFileThumbnailUpload(fileId, dataKeyVersion, thumbnail);
-    if (!res.ok) return false;
-    statuses.set(fileId, "uploaded");
-    storeFileThumbnailCache(fileId, thumbnail.plaintext); // Intended
+    const thumbnail = await generateThumbnail(
+      new Blob([fileBuffer], { type: fileInfo.contentType }),
+    );
+    if (!thumbnail) return false;
+
+    statuses.set(fileInfo.id, "uploading");
+
+    const res = await requestFileThumbnailUpload(
+      fileInfo.id,
+      thumbnail,
+      fileInfo.dataKey?.key!,
+      fileInfo.dataKey?.version!,
+    );
+    if (!res) return false;
+
+    statuses.set(fileInfo.id, "uploaded");
+    void thumbnail.arrayBuffer().then((buffer) => storeFileThumbnailCache(fileInfo.id, buffer));
    return true;
  },
  { concurrency: 4 },
@@ -77,20 +69,11 @@ export const requestThumbnailGeneration = async (fileInfo: FileInfo) => {
    await scheduler.schedule(
      async () => {
        statuses.set(fileInfo.id, "generation-pending");
-        file = await requestFileDownload(fileInfo.id, fileInfo.contentIv!, fileInfo.dataKey?.key!);
+        file = await requestFileDownload(fileInfo.id, fileInfo.dataKey?.key!, fileInfo.isLegacy!);
        return file.byteLength;
      },
      async () => {
-        const thumbnail = await generateThumbnail(
-          fileInfo.id,
-          file!,
-          fileInfo.contentType,
-          fileInfo.dataKey?.key!,
-        );
-        if (
-          !thumbnail ||
-          !(await requestThumbnailUpload(fileInfo.id, fileInfo.dataKey?.version!, thumbnail))
-        ) {
+        if (!(await requestThumbnailUpload(fileInfo, file!))) {
          statuses.set(fileInfo.id, "error");
        }
      },
--- a/src/routes/(main)/directory/[[id]]/+page.svelte
+++ b/src/routes/(main)/directory/[[id]]/+page.svelte
@@ -51,7 +51,7 @@
    if (!files || files.length === 0) return;

    for (const file of files) {
-      requestFileUpload(file, data.id, $hmacSecretStore?.get(1)!, $masterKeyStore?.get(1)!, () => {
+      requestFileUpload(file, data.id, $masterKeyStore?.get(1)!, $hmacSecretStore?.get(1)!, () => {
        return new Promise((resolve) => {
          duplicatedFile = file;
          resolveForDuplicateFileModal = resolve;
--- a/src/routes/(main)/directory/[[id]]/service.svelte.ts
+++ b/src/routes/(main)/directory/[[id]]/service.svelte.ts
@@ -81,14 +81,16 @@ export const requestDirectoryCreation = async (
 export const requestFileUpload = async (
  file: File,
  parentId: "root" | number,
-  hmacSecret: HmacSecret,
  masterKey: MasterKey,
+  hmacSecret: HmacSecret,
  onDuplicate: () => Promise<boolean>,
 ) => {
-  const res = await uploadFile(file, parentId, hmacSecret, masterKey, onDuplicate);
+  const res = await uploadFile(file, parentId, masterKey, hmacSecret, onDuplicate);
  if (!res) return false;

+  if (res.fileBuffer) {
    storeFileCache(res.fileId, res.fileBuffer); // Intended
+  }
  if (res.thumbnailBuffer) {
    storeFileThumbnailCache(res.fileId, res.thumbnailBuffer); // Intended
  }
--- a/src/routes/(main)/menu/+page.svelte
+++ b/src/routes/(main)/menu/+page.svelte
@@ -5,6 +5,7 @@

  import IconStorage from "~icons/material-symbols/storage";
  import IconImage from "~icons/material-symbols/image";
+  import IconLockReset from "~icons/material-symbols/lock-reset";
  import IconPassword from "~icons/material-symbols/password";
  import IconLogout from "~icons/material-symbols/logout";

@@ -41,6 +42,13 @@
    >
      썸네일
    </MenuEntryButton>
+    <MenuEntryButton
+      onclick={() => goto("/settings/migration")}
+      icon={IconLockReset}
+      iconColor="text-teal-500"
+    >
+      암호화 마이그레이션
+    </MenuEntryButton>
  </div>
  <div class="space-y-2">
    <p class="font-semibold">보안</p>
--- a/src/routes/api/file/[id]/[[thumbnail=thumbnail]]/download/+server.ts
+++ b/src/routes/api/file/[id]/[[thumbnail=thumbnail]]/download/+server.ts
@@ -0,0 +1,44 @@
+import { error } from "@sveltejs/kit";
+import { z } from "zod";
+import { parseRangeHeader, getContentRangeHeader } from "$lib/modules/http";
+import { authorize } from "$lib/server/modules/auth";
+import { getFileStream, getFileThumbnailStream } from "$lib/server/services/file";
+import type { RequestHandler, RouteParams } from "./$types";
+
+const downloadHandler = async (locals: App.Locals, params: RouteParams, request: Request) => {
+  const { userId } = await authorize(locals, "activeClient");
+
+  const zodRes = z
+    .object({
+      id: z.coerce.number().int().positive(),
+    })
+    .safeParse(params);
+  if (!zodRes.success) error(400, "Invalid path parameters");
+  const { id } = zodRes.data;
+
+  const getStream = params.thumbnail ? getFileThumbnailStream : getFileStream;
+  const { encContentStream, range } = await getStream(
+    userId,
+    id,
+    parseRangeHeader(request.headers.get("Range")),
+  );
+  return {
+    stream: encContentStream,
+    status: range ? 206 : 200,
+    headers: {
+      "Accept-Ranges": "bytes",
+      "Content-Length": String(range.end - range.start + 1),
+      "Content-Type": "application/octet-stream",
+      ...getContentRangeHeader(range),
+    },
+  };
+};
+
+export const GET: RequestHandler = async ({ locals, params, request }) => {
+  const { stream, ...init } = await downloadHandler(locals, params, request);
+  return new Response(stream as ReadableStream, init);
+};
+
+export const HEAD: RequestHandler = async ({ locals, params, request }) => {
+  return new Response(null, await downloadHandler(locals, params, request));
+};
--- a/src/routes/api/file/[id]/download/+server.ts
+++ b/src/routes/api/file/[id]/download/+server.ts
@@ -1,25 +0,0 @@
-import { error } from "@sveltejs/kit";
-import { z } from "zod";
-import { authorize } from "$lib/server/modules/auth";
-import { getFileStream } from "$lib/server/services/file";
-import type { RequestHandler } from "./$types";
-
-export const GET: RequestHandler = async ({ locals, params }) => {
-  const { userId } = await authorize(locals, "activeClient");
-
-  const zodRes = z
-    .object({
-      id: z.coerce.number().int().positive(),
-    })
-    .safeParse(params);
-  if (!zodRes.success) error(400, "Invalid path parameters");
-  const { id } = zodRes.data;
-
-  const { encContentStream, encContentSize } = await getFileStream(userId, id);
-  return new Response(encContentStream as ReadableStream, {
-    headers: {
-      "Content-Type": "application/octet-stream",
-      "Content-Length": encContentSize.toString(),
-    },
-  });
-};
--- a/src/routes/api/file/[id]/thumbnail/download/+server.ts
+++ b/src/routes/api/file/[id]/thumbnail/download/+server.ts
@@ -1,25 +0,0 @@
-import { error } from "@sveltejs/kit";
-import { z } from "zod";
-import { authorize } from "$lib/server/modules/auth";
-import { getFileThumbnailStream } from "$lib/server/services/file";
-import type { RequestHandler } from "./$types";
-
-export const GET: RequestHandler = async ({ locals, params }) => {
-  const { userId } = await authorize(locals, "activeClient");
-
-  const zodRes = z
-    .object({
-      id: z.coerce.number().int().positive(),
-    })
-    .safeParse(params);
-  if (!zodRes.success) error(400, "Invalid path parameters");
-  const { id } = zodRes.data;
-
-  const { encContentStream, encContentSize } = await getFileThumbnailStream(userId, id);
-  return new Response(encContentStream as ReadableStream, {
-    headers: {
-      "Content-Type": "application/octet-stream",
-      "Content-Length": encContentSize.toString(),
-    },
-  });
-};
--- a/src/routes/api/file/[id]/thumbnail/upload/+server.ts
+++ b/src/routes/api/file/[id]/thumbnail/upload/+server.ts
@@ -1,74 +0,0 @@
-import Busboy from "@fastify/busboy";
-import { error, text } from "@sveltejs/kit";
-import { Readable, Writable } from "stream";
-import { z } from "zod";
-import { authorize } from "$lib/server/modules/auth";
-import { fileThumbnailUploadRequest, type FileThumbnailUploadRequest } from "$lib/server/schemas";
-import { uploadFileThumbnail } from "$lib/server/services/file";
-import type { RequestHandler } from "./$types";
-
-export const POST: RequestHandler = async ({ locals, params, request }) => {
-  const { userId } = await authorize(locals, "activeClient");
-
-  const zodRes = z
-    .object({
-      id: z.coerce.number().int().positive(),
-    })
-    .safeParse(params);
-  if (!zodRes.success) error(400, "Invalid path parameters");
-  const { id } = zodRes.data;
-
-  const contentType = request.headers.get("Content-Type");
-  if (!contentType?.startsWith("multipart/form-data") || !request.body) {
-    error(400, "Invalid request body");
-  }
-
-  return new Promise<Response>((resolve, reject) => {
-    const bb = Busboy({ headers: { "content-type": contentType } });
-    const handler =
-      <T extends unknown[]>(f: (...args: T) => Promise<void>) =>
-      (...args: T) => {
-        f(...args).catch(reject);
-      };
-
-    let metadata: FileThumbnailUploadRequest | null = null;
-    let content: Readable | null = null;
-    bb.on(
-      "field",
-      handler(async (fieldname, val) => {
-        if (fieldname === "metadata") {
-          // Ignore subsequent metadata fields
-          if (!metadata) {
-            const zodRes = fileThumbnailUploadRequest.safeParse(JSON.parse(val));
-            if (!zodRes.success) error(400, "Invalid request body");
-            metadata = zodRes.data;
-          }
-        } else {
-          error(400, "Invalid request body");
-        }
-      }),
-    );
-    bb.on(
-      "file",
-      handler(async (fieldname, file) => {
-        if (fieldname !== "content") error(400, "Invalid request body");
-        if (!metadata || content) error(400, "Invalid request body");
-        content = file;
-
-        await uploadFileThumbnail(
-          userId,
-          id,
-          new Date(metadata.dekVersion),
-          metadata.contentIv,
-          content,
-        );
-        resolve(text("Thumbnail uploaded", { headers: { "Content-Type": "text/plain" } }));
-      }),
-    );
-    bb.on("error", (e) => {
-      content?.emit("error", e) ?? reject(e);
-    });
-
-    request.body!.pipeTo(Writable.toWeb(bb)).catch(() => {}); // busboy will handle the error
-  });
-};
--- a/src/routes/api/file/upload/+server.ts
+++ b/src/routes/api/file/upload/+server.ts
@@ -1,108 +0,0 @@
-import Busboy from "@fastify/busboy";
-import { error, json } from "@sveltejs/kit";
-import { Readable, Writable } from "stream";
-import { authorize } from "$lib/server/modules/auth";
-import {
-  fileUploadRequest,
-  fileUploadResponse,
-  type FileUploadResponse,
-} from "$lib/server/schemas";
-import { uploadFile } from "$lib/server/services/file";
-import type { RequestHandler } from "./$types";
-
-type FileMetadata = Parameters<typeof uploadFile>[0];
-
-const parseFileMetadata = (userId: number, json: string) => {
-  const zodRes = fileUploadRequest.safeParse(JSON.parse(json));
-  if (!zodRes.success) error(400, "Invalid request body");
-  const {
-    parent,
-    mekVersion,
-    dek,
-    dekVersion,
-    hskVersion,
-    contentHmac,
-    contentType,
-    contentIv,
-    name,
-    nameIv,
-    createdAt,
-    createdAtIv,
-    lastModifiedAt,
-    lastModifiedAtIv,
-  } = zodRes.data;
-  if ((createdAt && !createdAtIv) || (!createdAt && createdAtIv))
-    error(400, "Invalid request body");
-
-  return {
-    userId,
-    parentId: parent,
-    mekVersion,
-    encDek: dek,
-    dekVersion: new Date(dekVersion),
-    hskVersion,
-    contentHmac,
-    contentType,
-    encContentIv: contentIv,
-    encName: { ciphertext: name, iv: nameIv },
-    encCreatedAt: createdAt && createdAtIv ? { ciphertext: createdAt, iv: createdAtIv } : null,
-    encLastModifiedAt: { ciphertext: lastModifiedAt, iv: lastModifiedAtIv },
-  } satisfies FileMetadata;
-};
-
-export const POST: RequestHandler = async ({ locals, request }) => {
-  const { userId } = await authorize(locals, "activeClient");
-
-  const contentType = request.headers.get("Content-Type");
-  if (!contentType?.startsWith("multipart/form-data") || !request.body) {
-    error(400, "Invalid request body");
-  }
-
-  return new Promise<Response>((resolve, reject) => {
-    const bb = Busboy({ headers: { "content-type": contentType } });
-    const handler =
-      <T extends unknown[]>(f: (...args: T) => Promise<void>) =>
-      (...args: T) => {
-        f(...args).catch(reject);
-      };
-
-    let metadata: FileMetadata | null = null;
-    let content: Readable | null = null;
-    const checksum = new Promise<string>((resolveChecksum, rejectChecksum) => {
-      bb.on(
-        "field",
-        handler(async (fieldname, val) => {
-          if (fieldname === "metadata") {
-            // Ignore subsequent metadata fields
-            if (!metadata) {
-              metadata = parseFileMetadata(userId, val);
-            }
-          } else if (fieldname === "checksum") {
-            // Ignore subsequent checksum fields
-            resolveChecksum(val);
-          } else {
-            error(400, "Invalid request body");
-          }
-        }),
-      );
-      bb.on(
-        "file",
-        handler(async (fieldname, file) => {
-          if (fieldname !== "content") error(400, "Invalid request body");
-          if (!metadata || content) error(400, "Invalid request body");
-          content = file;
-
-          const { fileId } = await uploadFile(metadata, content, checksum);
-          resolve(json(fileUploadResponse.parse({ file: fileId } satisfies FileUploadResponse)));
-        }),
-      );
-      bb.on("finish", () => rejectChecksum(new Error("Invalid request body")));
-      bb.on("error", (e) => {
-        content?.emit("error", e) ?? reject(e);
-        rejectChecksum(e);
-      });
-    });
-
-    request.body!.pipeTo(Writable.toWeb(bb)).catch(() => {}); // busboy will handle the error
-  });
-};
--- a/src/routes/api/upload/[id]/chunks/[index]/+server.ts
+++ b/src/routes/api/upload/[id]/chunks/[index]/+server.ts
@@ -0,0 +1,37 @@
+import { error, text } from "@sveltejs/kit";
+import { Readable } from "stream";
+import type { ReadableStream } from "stream/web";
+import { z } from "zod";
+import { parseContentDigestHeader } from "$lib/modules/http";
+import { authorize } from "$lib/server/modules/auth";
+import { uploadChunk } from "$lib/server/services/upload";
+import type { RequestHandler } from "./$types";
+
+export const POST: RequestHandler = async ({ locals, params, request }) => {
+  const { userId } = await authorize(locals, "activeClient");
+
+  const zodRes = z
+    .object({
+      id: z.uuidv4(),
+      index: z.coerce.number().int().positive(),
+    })
+    .safeParse(params);
+  if (!zodRes.success) error(400, "Invalid path parameters");
+  const { id: sessionId, index: chunkIndex } = zodRes.data;
+
+  const encContentHash = parseContentDigestHeader(request.headers.get("Content-Digest"));
+  if (!encContentHash) {
+    error(400, "Invalid request headers");
+  } else if (!request.body) {
+    error(400, "Invalid request body");
+  }
+
+  await uploadChunk(
+    userId,
+    sessionId,
+    chunkIndex,
+    Readable.fromWeb(request.body as ReadableStream),
+    encContentHash,
+  );
+  return text("Chunk uploaded", { headers: { "Content-Type": "text/plain" } });
+};
--- a/src/service-worker/constants.ts
+++ b/src/service-worker/constants.ts
@@ -0,0 +1 @@
+export * from "../lib/constants";
--- a/src/service-worker/handlers/decryptFile.ts
+++ b/src/service-worker/handlers/decryptFile.ts
@@ -0,0 +1,156 @@
+import { DECRYPTED_FILE_URL_PREFIX, CHUNK_SIZE, ENCRYPTED_CHUNK_SIZE } from "../constants";
+import { decryptChunk, getEncryptedRange, getDecryptedSize } from "../modules/crypto";
+import { parseRangeHeader, getContentRangeHeader } from "../modules/http";
+import { getFile } from "../modules/opfs";
+import { fileMetadataStore } from "../stores";
+import type { FileMetadata } from "../types";
+
+const createResponse = (
+  stream: ReadableStream<Uint8Array>,
+  isRangeRequest: boolean,
+  range: { start: number; end: number; total: number },
+  contentType?: string,
+  downloadFilename?: string,
+) => {
+  const headers: Record<string, string> = {
+    "Accept-Ranges": "bytes",
+    "Content-Length": String(range.end - range.start + 1),
+    ...(isRangeRequest ? getContentRangeHeader(range) : {}),
+  };
+
+  if (contentType) {
+    headers["Content-Type"] = contentType;
+  }
+
+  if (downloadFilename) {
+    headers["Content-Disposition"] =
+      `attachment; filename*=UTF-8''${encodeURIComponent(downloadFilename)}`;
+  }
+
+  return new Response(stream, {
+    status: isRangeRequest ? 206 : 200,
+    headers,
+  });
+};
+
+const streamFromOpfs = async (
+  file: File,
+  metadata?: FileMetadata,
+  range?: { start?: number; end?: number },
+  downloadFilename?: string,
+) => {
+  const start = range?.start ?? 0;
+  const end = range?.end ?? file.size - 1;
+  if (start > end || start < 0 || end >= file.size) {
+    return new Response("Invalid range", { status: 416 });
+  }
+
+  return createResponse(
+    file.slice(start, end + 1).stream(),
+    !!range,
+    { start, end, total: file.size },
+    metadata?.contentType,
+    downloadFilename,
+  );
+};
+
+const streamFromServer = async (
+  id: number,
+  metadata: FileMetadata,
+  range?: { start?: number; end?: number },
+  downloadFilename?: string,
+) => {
+  const totalSize = getDecryptedSize(metadata.encContentSize, metadata.isLegacy);
+  const start = range?.start ?? 0;
+  const end =
+    range?.end ??
+    (range && !metadata.isLegacy ? Math.min(start + CHUNK_SIZE, totalSize) : totalSize) - 1;
+  if (start > end || start < 0 || end >= totalSize) {
+    return new Response("Invalid range", { status: 416 });
+  }
+
+  const encryptedRange = getEncryptedRange(start, end, metadata.encContentSize, metadata.isLegacy);
+  const apiResponse = await fetch(`/api/file/${id}/download`, {
+    headers: { Range: `bytes=${encryptedRange.start}-${encryptedRange.end}` },
+  });
+  if (apiResponse.status !== 206 || !apiResponse.body) {
+    return new Response("Failed to fetch encrypted file", { status: 502 });
+  }
+
+  if (metadata.isLegacy) {
+    const fileEncrypted = await apiResponse.arrayBuffer();
+    const decrypted = await decryptChunk(fileEncrypted, metadata.dataKey);
+    return createResponse(
+      new ReadableStream<Uint8Array>({
+        start(controller) {
+          controller.enqueue(new Uint8Array(decrypted.slice(start, end + 1)));
+          controller.close();
+        },
+      }),
+      !!range,
+      { start, end, total: totalSize },
+      metadata.contentType,
+    );
+  }
+
+  const totalChunks = encryptedRange.lastChunkIndex - encryptedRange.firstChunkIndex + 1;
+  let currentChunkIndex = 0;
+  let buffer = new Uint8Array(0);
+
+  const decryptingStream = new TransformStream<Uint8Array, Uint8Array>({
+    async transform(chunk, controller) {
+      const newBuffer = new Uint8Array(buffer.length + chunk.length);
+      newBuffer.set(buffer);
+      newBuffer.set(chunk, buffer.length);
+      buffer = newBuffer;
+
+      while (buffer.length >= ENCRYPTED_CHUNK_SIZE && currentChunkIndex < totalChunks - 1) {
+        const encryptedChunk = buffer.slice(0, ENCRYPTED_CHUNK_SIZE);
+        buffer = buffer.slice(ENCRYPTED_CHUNK_SIZE);
+
+        const decrypted = await decryptChunk(encryptedChunk.buffer, metadata.dataKey);
+        const sliceStart = currentChunkIndex === 0 ? start % CHUNK_SIZE : 0;
+        controller.enqueue(new Uint8Array(decrypted.slice(sliceStart)));
+        currentChunkIndex++;
+      }
+    },
+    async flush(controller) {
+      if (buffer.length > 0) {
+        const decrypted = await decryptChunk(buffer.buffer, metadata.dataKey);
+        const sliceStart = currentChunkIndex === 0 ? start % CHUNK_SIZE : 0;
+        const sliceEnd = (end % CHUNK_SIZE) + 1;
+        controller.enqueue(new Uint8Array(decrypted.slice(sliceStart, sliceEnd)));
+      }
+    },
+  });
+
+  return createResponse(
+    apiResponse.body.pipeThrough(decryptingStream),
+    !!range,
+    { start, end, total: totalSize },
+    metadata.contentType,
+    downloadFilename,
+  );
+};
+
+const decryptFileHandler = async (request: Request) => {
+  const url = new URL(request.url);
+  const fileId = parseInt(url.pathname.slice(DECRYPTED_FILE_URL_PREFIX.length), 10);
+  if (isNaN(fileId)) {
+    throw new Response("Invalid file id", { status: 400 });
+  }
+
+  const downloadFilename = url.searchParams.get("download") ?? undefined;
+  const metadata = fileMetadataStore.get(fileId);
+  const range = parseRangeHeader(request.headers.get("Range"));
+  const cache = await getFile(`/cache/${fileId}`);
+  if (cache) {
+    return streamFromOpfs(cache, metadata, range, downloadFilename);
+  } else if (metadata) {
+    return streamFromServer(fileId, metadata, range, downloadFilename);
+  } else {
+    return new Response("Decryption not prepared", { status: 400 });
+  }
+};
+
+export default decryptFileHandler;
--- a/src/service-worker/handlers/index.ts
+++ b/src/service-worker/handlers/index.ts
@@ -0,0 +1 @@
+export { default as decryptFile } from "./decryptFile";
--- a/src/service-worker/index.ts
+++ b/src/service-worker/index.ts
@@ -0,0 +1,43 @@
+/// <reference no-default-lib="true"/>
+/// <reference lib="esnext" />
+/// <reference lib="webworker" />
+/// <reference types="@sveltejs/kit" />
+
+import { DECRYPTED_FILE_URL_PREFIX } from "./constants";
+import { decryptFile } from "./handlers";
+import { fileMetadataStore } from "./stores";
+import type { ServiceWorkerMessage, ServiceWorkerResponse } from "./types";
+
+const self = globalThis.self as unknown as ServiceWorkerGlobalScope;
+
+self.addEventListener("message", (event) => {
+  const message: ServiceWorkerMessage = event.data;
+  switch (message.type) {
+    case "decryption-prepare":
+      fileMetadataStore.set(message.fileId, message);
+      event.source?.postMessage({
+        type: "decryption-ready",
+        fileId: message.fileId,
+      } satisfies ServiceWorkerResponse);
+      break;
+    default: {
+      const exhaustive: never = message.type;
+      return exhaustive;
+    }
+  }
+});
+
+self.addEventListener("fetch", (event) => {
+  const url = new URL(event.request.url);
+  if (url.pathname.startsWith(DECRYPTED_FILE_URL_PREFIX)) {
+    event.respondWith(decryptFile(event.request));
+  }
+});
+
+self.addEventListener("install", () => {
+  self.skipWaiting();
+});
+
+self.addEventListener("activate", (event) => {
+  event.waitUntil(self.clients.claim());
+});
--- a/src/service-worker/modules/crypto.ts
+++ b/src/service-worker/modules/crypto.ts
@@ -0,0 +1,40 @@
+import { ENCRYPTION_OVERHEAD, CHUNK_SIZE, ENCRYPTED_CHUNK_SIZE } from "../constants";
+
+export * from "../../lib/modules/crypto";
+
+export const getEncryptedRange = (
+  start: number,
+  end: number,
+  totalEncryptedSize: number,
+  isLegacy: boolean,
+) => {
+  if (isLegacy) {
+    return {
+      firstChunkIndex: 0,
+      lastChunkIndex: 0,
+      start: 0,
+      end: totalEncryptedSize - 1,
+    };
+  }
+
+  const firstChunkIndex = Math.floor(start / CHUNK_SIZE);
+  const lastChunkIndex = Math.floor(end / CHUNK_SIZE);
+  return {
+    firstChunkIndex,
+    lastChunkIndex,
+    start: firstChunkIndex * ENCRYPTED_CHUNK_SIZE,
+    end: Math.min((lastChunkIndex + 1) * ENCRYPTED_CHUNK_SIZE - 1, totalEncryptedSize - 1),
+  };
+};
+
+export const getDecryptedSize = (encryptedSize: number, isLegacy: boolean) => {
+  if (isLegacy) {
+    return encryptedSize - ENCRYPTION_OVERHEAD;
+  }
+
+  const fullChunks = Math.floor(encryptedSize / ENCRYPTED_CHUNK_SIZE);
+  const lastChunkEncSize = encryptedSize % ENCRYPTED_CHUNK_SIZE;
+  return (
+    fullChunks * CHUNK_SIZE + (lastChunkEncSize > 0 ? lastChunkEncSize - ENCRYPTION_OVERHEAD : 0)
+  );
+};
--- a/src/service-worker/modules/http.ts
+++ b/src/service-worker/modules/http.ts
@@ -0,0 +1 @@
+export * from "../../lib/modules/http";
--- a/src/service-worker/modules/opfs.ts
+++ b/src/service-worker/modules/opfs.ts
@@ -0,0 +1 @@
+export * from "../../lib/modules/opfs";
--- a/src/service-worker/stores.ts
+++ b/src/service-worker/stores.ts
@@ -0,0 +1,3 @@
+import type { FileMetadata } from "./types";
+
+export const fileMetadataStore = new Map<number, FileMetadata>();
--- a/src/service-worker/types.ts
+++ b/src/service-worker/types.ts
@@ -0,0 +1 @@
+export * from "../lib/serviceWorker/types";
--- a/src/trpc/router.server.ts
+++ b/src/trpc/router.server.ts
@@ -9,6 +9,7 @@ import {
  fileRouter,
  hskRouter,
  mekRouter,
+  uploadRouter,
  userRouter,
 } from "./routers";

@@ -20,6 +21,7 @@ export const appRouter = router({
  file: fileRouter,
  hsk: hskRouter,
  mek: mekRouter,
+  upload: uploadRouter,
  user: userRouter,
 });

--- a/src/trpc/routers/category.ts
+++ b/src/trpc/routers/category.ts
@@ -1,14 +1,14 @@
 import { TRPCError } from "@trpc/server";
 import { z } from "zod";
+import { CategoryIdSchema } from "$lib/schemas";
 import { CategoryRepo, FileRepo, IntegrityError } from "$lib/server/db";
-import { categoryIdSchema } from "$lib/server/schemas";
 import { router, roleProcedure } from "../init.server";

 const categoryRouter = router({
  get: roleProcedure["activeClient"]
    .input(
      z.object({
-        id: categoryIdSchema,
+        id: CategoryIdSchema,
        recurse: z.boolean().default(false),
      }),
    )
@@ -65,7 +65,7 @@ const categoryRouter = router({
  create: roleProcedure["activeClient"]
    .input(
      z.object({
-        parent: categoryIdSchema,
+        parent: CategoryIdSchema,
        mekVersion: z.int().positive(),
        dek: z.base64().nonempty(),
        dekVersion: z.date(),
--- a/src/trpc/routers/directory.ts
+++ b/src/trpc/routers/directory.ts
@@ -1,15 +1,15 @@
 import { TRPCError } from "@trpc/server";
 import { z } from "zod";
+import { DirectoryIdSchema } from "$lib/schemas";
 import { FileRepo, IntegrityError } from "$lib/server/db";
 import { safeUnlink } from "$lib/server/modules/filesystem";
-import { directoryIdSchema } from "$lib/server/schemas";
 import { router, roleProcedure } from "../init.server";

 const directoryRouter = router({
  get: roleProcedure["activeClient"]
    .input(
      z.object({
-        id: directoryIdSchema,
+        id: DirectoryIdSchema,
      }),
    )
    .query(async ({ ctx, input }) => {
@@ -59,7 +59,7 @@ const directoryRouter = router({
  create: roleProcedure["activeClient"]
    .input(
      z.object({
-        parent: directoryIdSchema,
+        parent: DirectoryIdSchema,
        mekVersion: z.int().positive(),
        dek: z.base64().nonempty(),
        dekVersion: z.date(),
--- a/src/trpc/routers/file.ts
+++ b/src/trpc/routers/file.ts
@@ -19,12 +19,12 @@ const fileRouter = router({

      const categories = await FileRepo.getAllFileCategories(input.id);
      return {
+        isLegacy: !!file.encContentIv,
        parent: file.parentId,
        mekVersion: file.mekVersion,
        dek: file.encDek,
        dekVersion: file.dekVersion,
        contentType: file.contentType,
-        contentIv: file.encContentIv,
        name: file.encName.ciphertext,
        nameIv: file.encName.iv,
        createdAt: file.encCreatedAt?.ciphertext,
@@ -53,12 +53,12 @@ const fileRouter = router({
      const files = await FileRepo.getFilesWithCategories(ctx.session.userId, input.ids);
      return files.map((file) => ({
        id: file.id,
+        isLegacy: !!file.encContentIv,
        parent: file.parentId,
        mekVersion: file.mekVersion,
        dek: file.encDek,
        dekVersion: file.dekVersion,
        contentType: file.contentType,
-        contentIv: file.encContentIv,
        name: file.encName.ciphertext,
        nameIv: file.encName.iv,
        createdAt: file.encCreatedAt?.ciphertext,
@@ -100,6 +100,10 @@ const fileRouter = router({
    return await MediaRepo.getMissingFileThumbnails(ctx.session.userId);
  }),

+  listLegacy: roleProcedure["activeClient"].query(async ({ ctx }) => {
+    return await FileRepo.getLegacyFileIds(ctx.session.userId);
+  }),
+
  rename: roleProcedure["activeClient"]
    .input(
      z.object({
@@ -158,7 +162,7 @@ const fileRouter = router({
        throw new TRPCError({ code: "NOT_FOUND", message: "File or its thumbnail not found" });
      }

-      return { updatedAt: thumbnail.updatedAt, contentIv: thumbnail.encContentIv };
+      return { updatedAt: thumbnail.updatedAt };
    }),
 });

--- a/src/trpc/routers/index.ts
+++ b/src/trpc/routers/index.ts
@@ -5,4 +5,5 @@ export { default as directoryRouter } from "./directory";
 export { default as fileRouter } from "./file";
 export { default as hskRouter } from "./hsk";
 export { default as mekRouter } from "./mek";
+export { default as uploadRouter } from "./upload";
 export { default as userRouter } from "./user";
--- a/src/trpc/routers/upload.ts
+++ b/src/trpc/routers/upload.ts
@@ -0,0 +1,362 @@
+import { TRPCError } from "@trpc/server";
+import { createHash } from "crypto";
+import { createReadStream, createWriteStream } from "fs";
+import { copyFile, mkdir } from "fs/promises";
+import mime from "mime";
+import { dirname } from "path";
+import { v4 as uuidv4 } from "uuid";
+import { z } from "zod";
+import { DirectoryIdSchema } from "$lib/schemas";
+import { FileRepo, MediaRepo, UploadRepo, IntegrityError } from "$lib/server/db";
+import db from "$lib/server/db/kysely";
+import env from "$lib/server/loadenv";
+import { safeRecursiveRm, safeUnlink } from "$lib/server/modules/filesystem";
+import { router, roleProcedure } from "../init.server";
+
+const UPLOADS_EXPIRES = 24 * 3600 * 1000; // 24 hours
+
+const sessionLocks = new Set<string>();
+
+const generateSessionId = async () => {
+  const id = uuidv4();
+  const path = `${env.uploadsPath}/${id}`;
+  await mkdir(path, { recursive: true });
+  return { id, path };
+};
+
+const uploadRouter = router({
+  startFileUpload: roleProcedure["activeClient"]
+    .input(
+      z.object({
+        chunks: z.int().positive(),
+        parent: DirectoryIdSchema,
+        mekVersion: z.int().positive(),
+        dek: z.base64().nonempty(),
+        dekVersion: z.date(),
+        hskVersion: z.int().positive().optional(),
+        contentType: z
+          .string()
+          .trim()
+          .nonempty()
+          .refine((value) => mime.getExtension(value) !== null),
+        name: z.base64().nonempty(),
+        nameIv: z.base64().nonempty(),
+        createdAt: z.base64().nonempty().optional(),
+        createdAtIv: z.base64().nonempty().optional(),
+        lastModifiedAt: z.base64().nonempty(),
+        lastModifiedAtIv: z.base64().nonempty(),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      const oneMinuteAgo = new Date(Date.now() - 60 * 1000);
+      const oneMinuteLater = new Date(Date.now() + 60 * 1000);
+      if (input.dekVersion <= oneMinuteAgo || input.dekVersion >= oneMinuteLater) {
+        throw new TRPCError({ code: "BAD_REQUEST", message: "Invalid DEK version" });
+      }
+
+      const { id, path } = await generateSessionId();
+
+      try {
+        await UploadRepo.createFileUploadSession({
+          id,
+          userId: ctx.session.userId,
+          path,
+          totalChunks: input.chunks,
+          expiresAt: new Date(Date.now() + UPLOADS_EXPIRES),
+          parentId: input.parent,
+          mekVersion: input.mekVersion,
+          encDek: input.dek,
+          dekVersion: input.dekVersion,
+          hskVersion: input.hskVersion ?? null,
+          contentType: input.contentType,
+          encName: { ciphertext: input.name, iv: input.nameIv },
+          encCreatedAt:
+            input.createdAt && input.createdAtIv
+              ? { ciphertext: input.createdAt, iv: input.createdAtIv }
+              : null,
+          encLastModifiedAt: { ciphertext: input.lastModifiedAt, iv: input.lastModifiedAtIv },
+        });
+        return { uploadId: id };
+      } catch (e) {
+        await safeRecursiveRm(path);
+
+        if (e instanceof IntegrityError) {
+          if (e.message === "Inactive MEK version") {
+            throw new TRPCError({ code: "BAD_REQUEST", message: "Invalid MEK version" });
+          } else if (e.message === "Inactive HSK version") {
+            throw new TRPCError({ code: "BAD_REQUEST", message: "Invalid HSK version" });
+          }
+        }
+        throw e;
+      }
+    }),
+
+  completeFileUpload: roleProcedure["activeClient"]
+    .input(
+      z.object({
+        uploadId: z.uuidv4(),
+        contentHmac: z.base64().nonempty().optional(),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      const { uploadId } = input;
+      if (sessionLocks.has(uploadId)) {
+        throw new TRPCError({ code: "CONFLICT", message: "Completion already in progress" });
+      } else {
+        sessionLocks.add(uploadId);
+      }
+
+      let filePath = "";
+
+      try {
+        const session = await UploadRepo.getUploadSession(uploadId, ctx.session.userId);
+        if (session?.type !== "file") {
+          throw new TRPCError({ code: "NOT_FOUND", message: "Invalid upload id" });
+        } else if (
+          (session.hskVersion && !input.contentHmac) ||
+          (!session.hskVersion && input.contentHmac)
+        ) {
+          throw new TRPCError({ code: "BAD_REQUEST", message: "Invalid content HMAC" });
+        } else if (session.uploadedChunks < session.totalChunks) {
+          throw new TRPCError({ code: "BAD_REQUEST", message: "Upload not completed" });
+        }
+
+        filePath = `${env.libraryPath}/${ctx.session.userId}/${uuidv4()}`;
+        await mkdir(dirname(filePath), { recursive: true });
+
+        const hashStream = createHash("sha256");
+        const writeStream = createWriteStream(filePath, { flags: "wx", mode: 0o600 });
+
+        for (let i = 1; i <= session.totalChunks; i++) {
+          for await (const chunk of createReadStream(`${session.path}/${i}`)) {
+            hashStream.update(chunk);
+            writeStream.write(chunk);
+          }
+        }
+
+        await new Promise<void>((resolve, reject) => {
+          writeStream.end((e: any) => (e ? reject(e) : resolve()));
+        });
+
+        const hash = hashStream.digest("base64");
+        const fileId = await db.transaction().execute(async (trx) => {
+          const { id: fileId } = await FileRepo.registerFile(trx, {
+            ...session,
+            userId: ctx.session.userId,
+            path: filePath,
+            contentHmac: input.contentHmac ?? null,
+            encContentHash: hash,
+            encContentIv: null,
+          });
+          await UploadRepo.deleteUploadSession(trx, uploadId);
+          return fileId;
+        });
+
+        await safeRecursiveRm(session.path);
+        return { file: fileId };
+      } catch (e) {
+        await safeUnlink(filePath);
+        throw e;
+      } finally {
+        sessionLocks.delete(uploadId);
+      }
+    }),
+
+  startFileThumbnailUpload: roleProcedure["activeClient"]
+    .input(
+      z.object({
+        file: z.int().positive(),
+        dekVersion: z.date(),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      const { id, path } = await generateSessionId();
+
+      try {
+        await UploadRepo.createThumbnailOrMigrationUploadSession({
+          id,
+          type: "thumbnail",
+          userId: ctx.session.userId,
+          path,
+          totalChunks: 1, // Up to 4 MiB
+          expiresAt: new Date(Date.now() + UPLOADS_EXPIRES),
+          fileId: input.file,
+          dekVersion: input.dekVersion,
+        });
+        return { uploadId: id };
+      } catch (e) {
+        await safeRecursiveRm(path);
+
+        if (e instanceof IntegrityError) {
+          if (e.message === "File not found") {
+            throw new TRPCError({ code: "NOT_FOUND", message: "Invalid file id" });
+          } else if (e.message === "Invalid DEK version") {
+            throw new TRPCError({ code: "BAD_REQUEST", message: e.message });
+          }
+        }
+        throw e;
+      }
+    }),
+
+  completeFileThumbnailUpload: roleProcedure["activeClient"]
+    .input(
+      z.object({
+        uploadId: z.uuidv4(),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      const { uploadId } = input;
+      if (sessionLocks.has(uploadId)) {
+        throw new TRPCError({ code: "CONFLICT", message: "Completion already in progress" });
+      } else {
+        sessionLocks.add(uploadId);
+      }
+
+      let thumbnailPath = "";
+
+      try {
+        const session = await UploadRepo.getUploadSession(uploadId, ctx.session.userId);
+        if (session?.type !== "thumbnail") {
+          throw new TRPCError({ code: "NOT_FOUND", message: "Invalid upload id" });
+        } else if (session.uploadedChunks < session.totalChunks) {
+          throw new TRPCError({ code: "BAD_REQUEST", message: "Upload not completed" });
+        }
+
+        thumbnailPath = `${env.thumbnailsPath}/${ctx.session.userId}/${uploadId}`;
+        await mkdir(dirname(thumbnailPath), { recursive: true });
+        await copyFile(`${session.path}/1`, thumbnailPath);
+
+        const oldThumbnailPath = await db.transaction().execute(async (trx) => {
+          const oldPath = await MediaRepo.updateFileThumbnail(
+            trx,
+            ctx.session.userId,
+            session.fileId,
+            session.dekVersion,
+            thumbnailPath,
+            null,
+          );
+          await UploadRepo.deleteUploadSession(trx, uploadId);
+          return oldPath;
+        });
+        await Promise.all([safeUnlink(oldThumbnailPath), safeRecursiveRm(session.path)]);
+      } catch (e) {
+        await safeUnlink(thumbnailPath);
+
+        if (e instanceof IntegrityError && e.message === "Invalid DEK version") {
+          // DEK rotated after this upload started
+          throw new TRPCError({ code: "CONFLICT", message: e.message });
+        }
+        throw e;
+      } finally {
+        sessionLocks.delete(uploadId);
+      }
+    }),
+
+  startMigrationUpload: roleProcedure["activeClient"]
+    .input(
+      z.object({
+        file: z.int().positive(),
+        chunks: z.int().positive(),
+        dekVersion: z.date(),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      const { id, path } = await generateSessionId();
+
+      try {
+        await UploadRepo.createThumbnailOrMigrationUploadSession({
+          id,
+          type: "migration",
+          userId: ctx.session.userId,
+          path,
+          totalChunks: input.chunks,
+          expiresAt: new Date(Date.now() + UPLOADS_EXPIRES),
+          fileId: input.file,
+          dekVersion: input.dekVersion,
+        });
+        return { uploadId: id };
+      } catch (e) {
+        await safeRecursiveRm(path);
+
+        if (e instanceof IntegrityError) {
+          if (e.message === "File not found") {
+            throw new TRPCError({ code: "NOT_FOUND", message: "Invalid file id" });
+          } else if (e.message === "File is not legacy") {
+            throw new TRPCError({ code: "BAD_REQUEST", message: e.message });
+          }
+        }
+        throw e;
+      }
+    }),
+
+  completeMigrationUpload: roleProcedure["activeClient"]
+    .input(
+      z.object({
+        uploadId: z.uuidv4(),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      const { uploadId } = input;
+      if (sessionLocks.has(uploadId)) {
+        throw new TRPCError({ code: "CONFLICT", message: "Completion already in progress" });
+      } else {
+        sessionLocks.add(uploadId);
+      }
+
+      let filePath = "";
+
+      try {
+        const session = await UploadRepo.getUploadSession(uploadId, ctx.session.userId);
+        if (session?.type !== "migration") {
+          throw new TRPCError({ code: "NOT_FOUND", message: "Invalid upload id" });
+        } else if (session.uploadedChunks < session.totalChunks) {
+          throw new TRPCError({ code: "BAD_REQUEST", message: "Upload not completed" });
+        }
+
+        filePath = `${env.libraryPath}/${ctx.session.userId}/${uuidv4()}`;
+        await mkdir(dirname(filePath), { recursive: true });
+
+        const hashStream = createHash("sha256");
+        const writeStream = createWriteStream(filePath, { flags: "wx", mode: 0o600 });
+
+        for (let i = 1; i <= session.totalChunks; i++) {
+          for await (const chunk of createReadStream(`${session.path}/${i}`)) {
+            hashStream.update(chunk);
+            writeStream.write(chunk);
+          }
+        }
+
+        await new Promise<void>((resolve, reject) => {
+          writeStream.end((e: any) => (e ? reject(e) : resolve()));
+        });
+
+        const hash = hashStream.digest("base64");
+        const oldPath = await db.transaction().execute(async (trx) => {
+          const { oldPath } = await FileRepo.migrateFileContent(
+            trx,
+            ctx.session.userId,
+            session.fileId,
+            filePath,
+            session.dekVersion!,
+            hash,
+          );
+          await UploadRepo.deleteUploadSession(trx, uploadId);
+          return oldPath;
+        });
+
+        await Promise.all([safeUnlink(oldPath), safeRecursiveRm(session.path)]);
+      } catch (e) {
+        await safeUnlink(filePath);
+
+        if (e instanceof IntegrityError && e.message === "File is not legacy") {
+          // File migrated after this upload started
+          throw new TRPCError({ code: "CONFLICT", message: e.message });
+        }
+        throw e;
+      } finally {
+        sessionLocks.delete(uploadId);
+      }
+    }),
+});
+
+export default uploadRouter;
--- a/src/workers/hmac.ts
+++ b/src/workers/hmac.ts
@@ -0,0 +1,25 @@
+import { hmac } from "@noble/hashes/hmac.js";
+import { sha256 } from "@noble/hashes/sha2.js";
+
+export interface ComputeMessage {
+  stream: ReadableStream;
+  key: Uint8Array;
+}
+
+export interface ResultMessage {
+  result: Uint8Array;
+}
+
+self.onmessage = async (event: MessageEvent<ComputeMessage>) => {
+  const h = hmac.create(sha256, event.data.key);
+  const reader = event.data.stream.getReader();
+
+  while (true) {
+    const { done, value } = await reader.read();
+    if (done) break;
+    h.update(value);
+  }
+
+  const result = h.digest();
+  self.postMessage({ result } satisfies ResultMessage, { transfer: [result.buffer] });
+};
--- a/svelte.config.js
+++ b/svelte.config.js
@@ -8,6 +8,7 @@ const config = {
    adapter: adapter(),
    alias: {
      $trpc: "./src/trpc",
+      $workers: "./src/workers",
    },
  },
 };
				`@@ -0,0 +1 @@`
				`export const DECRYPTED_FILE_URL_PREFIX = "/_internal/decryptedFile/";`
				`@@ -0,0 +1 @@`
				`export { default as decryptFile } from "./decryptFile";`
				`@@ -0,0 +1 @@`
				`export * from "../lib/serviceWorker/types";`