DokanCloudFS

DokanCloudFS is a virtual filesystem for various publicly accessible cloud storage services on the Microsoft Windows platform.

Objective

DokanCloudFS implements a virtual filesystem that allows direct mounting of various publicly accessible cloud storage services on the Microsoft Windows platform.

Mounted cloud storage drives appear as ordinary removable drives in Windows Explorer (albeit very slow ones) and can be used just about like any local drive or file share. All content written through DokanCloudFS is transparently encrypted on the cloud storage backend.

Some limitations apply concerning transfer speed, maximum file size, permissions, and alternate streams depending on parameters of the cloud storage service used as a backend.

Features

• Mounting of cloud storage volumes as removable drives into Windows Explorer
  • number of mounted volumes only limited by available drive letters
  • mounting of multiple accounts of the same cloud storage service in parallel
• Full support for interactive file manipulation in Winows Explorer including but not limited to
  • copying and moving of multiple files and folders between DokanCloudFS drives and other drives
  • opening of files in default application via Mouse double click
  • right-click-menu on drive, files, and folders with access to menu commands and drive/file properties
  • thumbnails display for media files
• transparent encryption and decryption of all file content via AESCrypt
  • encryption key configurable per drive

Supported Cloud storage services

DokanCloudFS requires a gateway assembly for any cloud storage service to be used as a backend.

The expected gateway interface types and a set of prefabricated gateways can be taken from the GitHub repository of the related CloudFS project.
The associated NuGet packages CloudFS and CloudFS-Signed include preconfigured API keys for the included cloud storage services and are ready to use.

System Requirements

• Platform
  • .NET 4.6
• Drivers
  • Dokany driver 0.8.0 or greater
• Operating system
  • tested on Windows 8.1 x64 and Windows Server 2012 R2
  • expected to run on Windows 7/8/8.1/10 and Windows Server 2008(R2)/2012(R2)

Local compilation

• Compile the CloudFS solution
• Copy all assemblies from the Gateways directory in the build output of CloudFS.GatewayTests to the Library directory of DokanCloudFS
• Compile the DokanCloudFS solution
• Check that the Gateways directory in the build output of DokanCloudFS.Mounter contains all desired gateway assemblies and their dependencies (e.g. Newtonsoft.JSON.dll)

Usage

• Configure the desired mount points in DokanCloudFS.Mounter's configuration file App.config. See below for a sample configuration.
• Run IgorSoft.DokanCloudFS.Mounter.exe from the command line

Sample configuration

  <mount threads="5">
    <drives>
      <drive schema="onedrive" userName="OneDriveUser" root="Q:" encryptionKey="MyOneDriveSecret&amp;I" timeout="300" />
      <!--<drive schema="box" userName="BoxUser" root="R:" encryptionKey="MyBoxSecret&amp;I" timeout="300" />
      <drive schema="copy" userName="CopyUser" root="S:" encryptionKey="MyCopySecret&amp;I" timeout="300" />
      <drive schema="gdrive" userName="GDriveUser" root="T:" encryptionKey="MyGDriveSecret&amp;I" timeout="300" />
      <drive schema="mega" userName="MegaUser" root="U:" encryptionKey="MyMegaSecret&amp;I" timeout="300" />
      <drive schema="pcloud" userName="pCloudUser" root="V:" encryptionKey="MypCloudSecret&amp;I" timeout="300" />-->
    </drives>
  </mount>

Configuration options:

• Global
  • threads: Number of concurrent threads used by the Dokan driver.
    Defaults to 5.
• Per drive
  • schema: Selects the cloud storage service gateway to be used.
    Must correspond to one of the CloudFS gateways installed in the Gateways\ subdirectory. Presently supports the following values:
    • onedrive (tested)
    • box, copy, gdrive, mega, pcloud (test pending)
  • userName: User account to be displayed in the mounted drive label.
  • root: The drive letter to be used as mount point for the cloud drive.
    Choose a free drive letter such as L:.
  • encryptionKey: An arbitrary symmetric key for the transparent client-side AES encryption.
    Leave this empty only if you really want to store content without encryption.
  • timeout: The timeout value for file operations on this drive measured in seconds.
    A value of 300 should suffice for all but the slowest connections.

Limitations

• DokanCloudFS only supports mounting of a cloud storage volume's root directory.
• The maximum supported file size varies between different cloud storage services. Moreover, the precise limits are not always disclosed.
  Exceeding the size limit in a file writing operation will result in either a timout or a service error.
• The files in a DokanCloudFS drive do not allow true random access, instead they are rather read or written as a whole.
  Depending on the target application it may be possible to edit a file directly in the DokanCloudFS drive, otherwise it must be copied to a conventional drive for processing.
• DokanCloudFS keeps an internal cache of directory metadata for increased performance. Changes made to the cloud storage volume outside of DokanCloudFS will not be automatically synchronized with this cache, therefore any form of concurrent write access may lead to unexpected results or errors.
• The only encrypted file format supported by DokanCloudFS is the AESCrypt file format.
• DokanCloudFS distinguishes encryption keys on a per-drive scale only. It is not possible to assign encryption keys to specific subdirectories or to individual files.
  Although you could, in theory, mount several copies of the same cloud service volume in parallel, these copies will not synchronize their cached directory structures in any way (see above).
  A future version of DokanCloudFS will support read-only access to unencrypted content on the cloud storage volume.

Remarks

Due to the nature of the Dokan kernel-mode drivers involved, any severe errors inside DokanCloudFS can result in Windows Bluescreens.

Don't install this project on production environments.

You have been warned.

Release Notes

• 2015-12-30 Version 1.0.0.0 - Initial release. This version has not been extensively tested apart from the OneDrive gateway - expect bugs.

Future plans

• improve stability
• improve performance
• allow alternate encryption schemes
• allow read-access to unencrypted content on cloud storage volumes
• allow mounting and unmounting of individual drives without restarting the mounter process

References

DokanCloudFS would not have been possible without the expertise and great effort devoted by their respective creators to the following projects:

• Dokany - The User mode file system library for windows (see Dokan for the entire Dokany ecosystem, Dokany for the specific driver)
• Dokan.NET - The Dokan DotNET wrapper (see Dokan.NET Binding)
• SharpAESCrypt - A C# implementation of the AESCrypt file format (see SharpAESCrypt)
• Moq - The most popular and friendly mocking framework for .NET (see Moq)
• SemanticTypes - Support for implementing semantic types (see SemanticTypes)