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>

database/factories/ShareFactory.php

@@ -27,9 +27,22 @@ class ShareFactory extends Factory
             'max_downloads' => null,
             'download_count' => 0,
             'total_size' => 0,
+            'completed_at' => now(),
         ];
     }
 
+    /**
+     * A share whose files are still being uploaded.
+     */
+    public function pending(): static
+    {
+        return $this->state(fn (array $attributes) => [
+            'encryption_key' => bin2hex(random_bytes(32)),
+            'encryption_salt' => null,
+            'completed_at' => null,
+        ]);
+    }
+
     public function withPassword(string $password = 'secret'): static
     {
         return $this->state(fn (array $attributes) => [

database/factories/ShareFileFactory.php

@@ -25,6 +25,20 @@ class ShareFileFactory extends Factory
             'stored_path' => 'shares/'.fake()->uuid().'.enc',
             'file_size' => fake()->numberBetween(1024, 10485760),
             'mime_type' => 'text/plain',
+            'uploaded_chunks' => 1,
+            'completed_at' => now(),
         ];
     }
+
+    /**
+     * A file whose chunks have not all arrived yet.
+     */
+    public function uploading(): static
+    {
+        return $this->state(fn (array $attributes) => [
+            'mime_type' => null,
+            'uploaded_chunks' => 0,
+            'completed_at' => null,
+        ]);
+    }
 }

database/migrations/2026_09_16_181040_add_upload_state_to_shares_and_share_files.php

@@ -0,0 +1,44 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * Shares and files that exist already were complete when they were created.
+     */
+    public function up(): void
+    {
+        Schema::table('shares', function (Blueprint $table) {
+            $table->text('wrapped_key')->nullable()->after('encryption_salt');
+            $table->timestamp('completed_at')->nullable()->after('total_size');
+        });
+
+        Schema::table('share_files', function (Blueprint $table) {
+            $table->unsignedInteger('uploaded_chunks')->default(0)->after('mime_type');
+            $table->timestamp('completed_at')->nullable()->after('uploaded_chunks');
+        });
+
+        DB::table('shares')->update(['completed_at' => DB::raw('created_at')]);
+        DB::table('share_files')->update(['completed_at' => DB::raw('created_at')]);
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('shares', function (Blueprint $table) {
+            $table->dropColumn(['wrapped_key', 'completed_at']);
+        });
+
+        Schema::table('share_files', function (Blueprint $table) {
+            $table->dropColumn(['uploaded_chunks', 'completed_at']);
+        });
+    }
+};