BeLikeSohan/arthurmorgan

Arthur Morgan

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Arthur Morgan is an experimental Flutter desktop client for storing encrypted files in Google Drive. It signs in with Google OAuth, creates or reuses an ArthurMorgan folder in Drive, encrypts local files before upload, and decrypts files locally when previewing or downloading them.

Arthur Morgan screenshot

What it does

• Signs in to a Google account with OAuth 2.0.
• Uses the Google Drive API v3 to list, upload, and download files.
• Creates an ArthurMorgan folder in Drive, either at Drive root or inside a user-selected parent folder.
• Stores a small verification file named arthurmorgan to check the encryption password on later launches.
• Encrypts file contents before upload.
• Encrypts uploaded filenames before storing them in Drive.
• Decrypts filenames locally for the in-app file grid.
• Supports multiple-file upload from the title bar upload button.
• Supports single-file download to the app documents directory.
• Supports image preview by downloading and decrypting image files in memory.
• Provides a Fluent UI desktop interface with custom window controls and configurable window effects.

Current status

This project is a work in progress. The repository contains Flutter platform folders for Android, iOS, Linux, macOS, Windows, and web, but the app code is currently desktop-oriented. It uses dart:io, desktop window APIs, local browser OAuth redirects, and desktop file picking behavior.

Implemented and planned features

Feature	Status
Google OAuth sign-in	Implemented
Remember OAuth credentials locally	Implemented
Select Drive root or a named parent folder	Implemented
Initialize an ArthurMorgan Drive folder	Implemented
Password verification for an existing folder	Implemented
Encrypt file contents	Implemented
Encrypt filenames	Implemented
Upload one or more files	Implemented
List encrypted Drive files with decrypted names	Implemented
Download a single file	Implemented
Preview decrypted image files	Implemented
Logout	Implemented
Create folders from the UI	Not implemented
Download multiple files	Not implemented
Drive thumbnails	Not implemented
Production-grade encryption/key management	Not implemented

How storage works

On first setup, Arthur Morgan creates a folder named ArthurMorgan in Google Drive. If the user enters a custom parent folder name, the app looks for that folder and creates or reads ArthurMorgan inside it. Otherwise, it uses the Drive root.

The setup password is used to create an AES key. The app stores an encrypted verification string in a Drive file named arthurmorgan. On later launches, it downloads that verification file and checks the entered password before decrypting the file list.

Uploaded files are encrypted locally first, then uploaded to Drive. Downloaded files are decrypted locally and saved under:

<application documents directory>/ArthurMorgan/Downloads/

Security notes

Arthur Morgan should be treated as experimental software, not as a production backup or password manager.

• The app requests the full Google Drive OAuth scope: https://www.googleapis.com/auth/drive.
• Encryption is implemented locally with AES-CBC through the current Dart dependencies.
• The password is padded into a 32-character key by the app code.
• The password is not recoverable from the app. Losing it means the uploaded encrypted files cannot be decrypted by this client.
• The encryption design has not been audited.
• OAuth credentials are cached with shared_preferences.

Requirements

• Flutter SDK compatible with Dart >=2.18.4 <3.0.0.
• A Google Cloud project with the Google Drive API enabled.
• OAuth credentials for a Desktop app.
• Desktop build tools for your target platform.

For Windows development, install the Flutter Windows desktop prerequisites. For Linux or macOS, install the matching Flutter desktop toolchain and any plugin-specific native dependencies required by Flutter.

Google Cloud setup

1. Open the Google Cloud Console.
2. Create or select a project.
3. Enable Google Drive API for the project.
4. Configure the OAuth consent screen.
5. Create OAuth client credentials with application type Desktop app.
6. Download the OAuth client JSON file.
7. Place the JSON file in the app's working directory before launching Arthur Morgan.

The app scans the current working directory for a .json file and reads installed.client_id and installed.client_secret from it. Keep only the intended OAuth client JSON beside the executable or in the project root when running from source.

If your Google Cloud app is still in testing mode, add your Google account as a test user on the OAuth consent screen.

Running from source

Clone the repository and install dependencies:

git clone https://github.com/BeLikeSohan/arthurmorgan.git
cd arthurmorgan
flutter pub get

Put the downloaded OAuth desktop client JSON file in the repository root, then run the desktop app:

flutter run -d windows

Use the matching device id for another desktop target:

flutter run -d linux
flutter run -d macos

Building

Build a release binary for your platform:

flutter build windows
flutter build linux
flutter build macos

After building, place the Google OAuth desktop client JSON file next to the executable or launch the app from a working directory that contains the JSON file.

Basic usage

1. Start the app with the OAuth client JSON available in the working directory.
2. Click Sign in with Google Account and complete the browser-based OAuth flow.
3. Choose where Arthur Morgan should look for its Drive folder. Leave the folder name empty to use Drive root.
4. For a new Drive setup, choose Setup Arthur Morgan and enter an encryption password.
5. For an existing setup, enter the same password used when the folder was created.
6. Use Upload in the title bar to pick one or more files.
7. Select a file in the grid to view details, preview images, or download the decrypted file.

Project structure

lib/
  main.dart                         App bootstrap, providers, navigation, OAuth JSON loading
  functions/
    googleoauthmanager.dart         Browser OAuth flow and OAuth client creation
    gdrivemanager.dart              Google Drive API operations
    filehandler.dart                File picking, encryption, decryption, password verification
    preferencesmanager.dart         Local persisted settings and OAuth credential cache
    stylehandler.dart               Desktop window effect handling
  providers/                        ChangeNotifier state for auth, Drive, settings, sheets, tasks
  pages/                            Sign-in, dashboard, and settings UI
  widgets/                          Custom title bar and shared UI widgets
  models/                           File metadata models

Development notes

• State management is based on provider.
• The UI uses fluent_ui.
• Google API access is provided by googleapis and oauth2.
• Local file selection uses file_picker.
• Window effects use flutter_acrylic and window_manager.
• The default app theme is currently dark.

Known limitations

• The New Folder button is disabled.
• Downloads are single-file only.
• There is no delete, rename, move, search, or conflict handling UI.
• Image previews require downloading and decrypting the file first.
• Folder lookup is name-based, so duplicate Google Drive folder names may cause ambiguous behavior.
• The app currently picks the first JSON-looking file it finds in the working directory.
• Some settings UI is present but not fully connected to app-wide theme behavior.