Encrypt uploads in the browser and send them in chunks

A 6 GB upload kept a customer waiting long after its progress bar
reached 100%. The server wrote every upload three times: PHP's
temporary file, Livewire's copy of it ("Processing files...") and the
encrypted file ("Create Share Link"), each a full rewrite of a slow
disk. The unencrypted copy also stayed behind in livewire-tmp.

Now the uploader's browser encrypts each file in 16 MB chunks with
WebCrypto and PUTs them one at a time; the server checks each chunk in
memory and writes it once, already encrypted. Creating the share only
wraps its key and saves the options. A 200 MB upload through the
Docker image took 2.8 s, and its download matched byte for byte.

- SEALCHK2: a 19-byte header (chunk size, 7-byte nonce prefix), then
  ciphertext and tag per chunk. Each nonce holds the chunk index and a
  last-chunk flag (the STREAM construction), so cut or reordered files
  fail to decrypt. SEALCHK1 and the single-block format still read.
- Envelope encryption: one random key per share. With a password it is
  wrapped with Argon2id (sodium, libsodium's interactive limits) in
  shares.wrapped_key, which names its parameters. Password shares from
  before keep their PBKDF2-derived key.
- The upload page registers each selection with FileUploader into a
  pending share of its own, lists the files with their progress, retries
  a failed chunk after 1-16 s, then offers Retry; Remove and Cancel
  abort. UploadChunkController only accepts chunks from the session that
  started the share: a repeat is acknowledged, a skip gets 409 with the
  count stored. Chunks go out as Blobs, which Chromium sends about eight
  times faster than ArrayBuffers.
- Uploads need a secure context: over plain HTTP the page says HTTPS is
  needed and takes no files. The Docker image gains AUTO_HTTPS, which
  serves Let's Encrypt on 443 for SERVER_NAME and redirects 80; without
  it the container stays on HTTP 80 behind a proxy. docker/Caddyfile was
  never loaded and is gone; docker/healthcheck.sh covers both modes.
- "Download all" streams the ZIP with maennchen/zipstream-php (STORE,
  ZIP64) instead of decrypting whole files into memory and writing the
  archive unencrypted to /tmp.
- Pending shares count towards the quota, stay out of the admin
  dashboard and 404 everywhere else. shares:cleanup deletes uploads idle
  for 4 hours and Livewire temporary files older than that.
- PHP's upload limits no longer cap the admin's max file size and
  default to 64M; LIVEWIRE_MAX_UPLOAD_TIME is gone and
  UPLOAD_CHUNK_SIZE_MB is new.
- Tests cover the format, key wrapping, registration limits, the chunk
  endpoint's answers, completing a share, the streamed ZIP, cleanup,
  and in Chromium a real chunked upload and the HTTPS warning; the
  selected-files overflow test runs again. README, website, CHANGELOG
  and .ai/rules follow.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/Feature/SecurityAuditTest.php

@@ -4,8 +4,8 @@ use App\Livewire\Admin\AdminSettings;
 use App\Livewire\FileUploader;
 use App\Livewire\ShareDownload;
 use App\Models\Share;
+use App\Models\ShareFile;
 use App\Models\User;
-use App\Services\FileEncryptionService;
 use App\Services\ShareService;
 use Illuminate\Http\UploadedFile;
 use Illuminate\Support\Facades\RateLimiter;
@@ -94,23 +94,17 @@ test('rate limiter clears after successful password verification', function () {
 test('share password must be at least 8 characters', function () {
     Storage::fake('shares');
 
-    $file = UploadedFile::fake()->create('file.txt', 100);
-
     Livewire::test(FileUploader::class)
-        ->set('files', [$file])
         ->set('usePassword', true)
         ->set('password', 'short')
         ->call('createShare')
-        ->assertHasErrors(['password']);
+        ->assertHasErrors(['password' => 'min']);
 });
 
 test('share password of 8 characters is accepted', function () {
     Storage::fake('shares');
 
-    $file = UploadedFile::fake()->create('file.txt', 100);
-
     Livewire::test(FileUploader::class)
-        ->set('files', [$file])
         ->set('usePassword', true)
         ->set('password', 'longenough')
         ->call('createShare')
@@ -151,42 +145,17 @@ test('setup wizard createAdmin is blocked when admin already exists', function (
 test('content disposition handles special characters in filename', function () {
     Storage::fake('shares');
 
-    $service = app(ShareService::class);
-    $encryptionService = app(FileEncryptionService::class);
-
-    $file = UploadedFile::fake()->create('normal.txt', 100);
-
-    $share = $service->createShare([
-        ['file' => $file, 'relativePath' => null],
+    $share = app(ShareService::class)->createShare([
+        ['file' => UploadedFile::fake()->createWithContent('normal.txt', 'test content'), 'relativePath' => null],
     ]);
-
-    $share->load('files');
     $shareFile = $share->files->first();
+    $shareFile->update(['original_name' => 'file"with"quotes.txt']);
 
-    $shareFile->original_name = 'file"with"quotes.txt';
-    $shareFile->save();
+    $response = $this->get(route('share.download.file', [$share, $shareFile]));
 
-    $encryptedDir = Storage::disk('shares')->path($share->token);
-    if (! is_dir($encryptedDir)) {
-        mkdir($encryptedDir, 0755, true);
-    }
-    $encryptedPath = $encryptedDir.'/'.basename($shareFile->stored_path);
-    $tempSource = tempnam(sys_get_temp_dir(), 'test');
-    file_put_contents($tempSource, 'test content');
-    $encryptionService->encryptFile($tempSource, $encryptedPath, $share->encryption_key);
-    unlink($tempSource);
-
-    $response = $encryptionService->decryptFileStream(
-        $encryptedPath,
-        $share->encryption_key,
-        'file"with"quotes.txt',
-        'text/plain',
-        12,
-    );
-
-    $contentDisposition = $response->headers->get('Content-Disposition');
-    expect($contentDisposition)->not->toContain('file"with"quotes.txt');
-    expect($contentDisposition)->toContain('attachment');
+    expect($response->headers->get('Content-Disposition'))
+        ->toContain('attachment')
+        ->not->toContain('file"with"quotes.txt');
 });
 
 // --- SVG upload rejected ---
@@ -194,11 +163,9 @@ test('content disposition handles special characters in filename', function () {
 test('svg upload is rejected for site logo', function () {
     $admin = User::query()->where('is_admin', true)->first();
 
-    $phpMaxMb = AdminSettings::phpMaxUploadMb();
-
     Livewire::actingAs($admin)
         ->test(AdminSettings::class)
-        ->set('maxFileSize', $phpMaxMb)
+        ->set('maxFileSize', 100)
         ->set('siteLogo', UploadedFile::fake()->create('logo.svg', 100, 'image/svg+xml'))
         ->call('saveSettings')
         ->assertHasErrors(['siteLogo']);
@@ -206,52 +173,26 @@ test('svg upload is rejected for site logo', function () {
 
 // --- Relative path validation (Zip Slip prevention) ---
 
-test('relative paths with directory traversal are sanitized', function () {
+test('relative paths from a dropped folder that could reach outside the share are dropped', function (string $relativePath) {
     Storage::fake('shares');
 
-    $file = UploadedFile::fake()->create('file.txt', 100);
-
     Livewire::test(FileUploader::class)
-        ->set('files', [$file])
-        ->set('relativePaths', ['../../etc/passwd'])
-        ->call('createShare')
-        ->assertRedirectContains('/share/');
+        ->call('registerFiles', [['name' => 'file.txt', 'size' => 100, 'path' => $relativePath]]);
 
-    $share = Share::query()->first();
-    $shareFile = $share->files->first();
-    expect($shareFile->relative_path)->toBeNull();
-});
-
-test('relative paths with absolute paths are sanitized', function () {
-    Storage::fake('shares');
-
-    $file = UploadedFile::fake()->create('file.txt', 100);
-
-    Livewire::test(FileUploader::class)
-        ->set('files', [$file])
-        ->set('relativePaths', ['/etc/passwd'])
-        ->call('createShare')
-        ->assertRedirectContains('/share/');
-
-    $share = Share::query()->first();
-    $shareFile = $share->files->first();
-    expect($shareFile->relative_path)->toBeNull();
-});
+    expect(ShareFile::query()->sole()->relative_path)->toBeNull();
+})->with([
+    'directory traversal' => '../../etc/passwd',
+    'absolute path' => '/etc/passwd',
+    'windows traversal' => '..\\..\\windows\\system.ini',
+]);
 
 test('valid relative paths are preserved', function () {
     Storage::fake('shares');
 
-    $file = UploadedFile::fake()->create('file.txt', 100);
-
     Livewire::test(FileUploader::class)
-        ->set('files', [$file])
-        ->set('relativePaths', ['folder/subfolder/file.txt'])
-        ->call('createShare')
-        ->assertRedirectContains('/share/');
+        ->call('registerFiles', [['name' => 'file.txt', 'size' => 100, 'path' => 'folder/subfolder/file.txt']]);
 
-    $share = Share::query()->first();
-    $shareFile = $share->files->first();
-    expect($shareFile->relative_path)->toBe('folder/subfolder/file.txt');
+    expect(ShareFile::query()->sole()->relative_path)->toBe('folder/subfolder/file.txt');
 });
 
 // --- Security headers ---