Keep previous versions when editing files

Cyberduck 9 adds a new custom file versioning feature for protocols with no native versioning support, such as FTP/SFTP and WebDAV.

The feature is added as a security measure to reduce the risk of file loss when editing changes. You can enable the option by default in the Editor tab in Preferences.

The versions can be previewed, deleted or restored in Edit Info Versions with the same user interface as when working with revisions from protocols with native versioning support such as a versioned bucket in S3.

Technically instead of overwriting files, previous versions are moved to a folder named .duckversions created adjacent to the edited file. The documentation has more details.

Connect to ownCloud Infinite Scale (oCIS) using OAuth

ownCloud Infinite Scale is a user-centric, cloud-native, open source, file sharing and collaboration platform that offers infinite scalability and enables complete digital sovereignty. 

ownCloud Infinite Scale uses federated authentication with Keycloak as the identity provider by default. To connect using Cyberduck or Mountain Duck.

We will provide sample steps to connect to ownCloud Infinite Scale (oCIS) using OAuth 2.0/OpenID Connect (OIDC). It requires the client registration in the identity provider in ownCloud and a custom connection profile for Cyberduck & Mountain Duck. To allow to test this without a custom deployment, the sample makes use of the public instance running at with the identity provider at You can login with the username “admin” and password “admin”. Note that these demo instances are wiped periodically and all data and configuration is temporarily available only.

Import client configuration

You will need to import a client configuration for Keycloak to allow OAuth authentications from Cyberduck & Mountain Duck. The configuration registers a OAuth Client ID with the redirect URIs x-cyberduck-action:oauth and x-mountainduck-action:oauth set to allow a seamless login integration.

Connection Profile

The connection profile defines the custom OAuth Client ID to be used to connect to ownCloud including the authorization and token URLs used for authentication with the Keycloak identity provider. The connection profile matching the above client registration is

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "">
<plist version="1.0">
        <string>ownCloud Infinite Scale</string>
        <key>Default Nickname</key>
        <string>ownCloud Infinite Scale</string>
        <key>Default Hostname</key>
        <key>Default Path</key>
        <key>Path Configurable</key>
        <key>Hostname Configurable</key>
        <key>OAuth Configurable</key>
        <key>OAuth Authorization Url</key>
        <key>OAuth Token Url</key>
        <key>OAuth Client ID</key>
        <key>OAuth Client Secret</key>
        <key>OAuth Redirect Url</key>
        <key>Password Configurable</key>
        <key>Username Configurable</key>

Save the file with the suffix .cyberduckprofile and double click to install and register with Cyberduck & Mountain Duck. This will enable the protocol option ownCloud Infinite Scale in the bookmark configuration.

Connect to S3 with web identity federation

The latest versions of Cyberduck & Mountain Duck now allow to connect to S3 by authenticating with an OpenID Connect (OIDC) identity provider.

Connections to S3 with web identity federation use AWS Security Token Service (STS) API to obtain temporary security credentials to authenticate with S3.

With web identity federation, you don’t need to (…) manage your own user identities. Instead, users of your app can sign in using a well-known external OpenID Connect (OIDC)-compatible IdP. They can receive an authentication token, and then exchange that token for temporary security credentials in AWS that map to an IAM role with permissions to use the resources in your AWS account. Using an IdP helps you keep your AWS account secure, because you don’t users to have long-term security credentials.

Default connection profiles for Google and Azure

Default connection profiles are provided to use Google or Azure AD as an identity provider in conjunction with AWS.

These default profiles will prompt users for the Role ARN configured in AWS IAM referencing the trust relationship configured with the identity provider. Assigned by AWS this has a format similar to arn:aws:iam::930717317329:role/my-role-name.

Configuration in AWS IAM

  1. Add an identity provider in IAM. Refer to the documentation from AWS.
  2. Assign a role. The role is crucial as it contains both the trust relationship with the identity provider and permission policy:
  • The trust policy restricts access to users authenticated with a specific identity provider and allows to filter for specific users in the Condition statement with access to the JSON Web Token (JWT) claims that can be matched.
  • With the permission policy attached it limits access to a predefined set of buckets or keys.

Refer to the AWS documentation on Creating a role for web identity or OpenID Connect Federation.

The role that your application assumes must trust the identity provider that is associated with the identity token. In other words, the identity provider must be specified in the role’s trust policy. The call to AssumeRoleWithWebIdentity should include the ARN of the role that is specific to the provider through which the user signed in.

Custom Integration

We have made available documentation to write your own connection profile for different combinations of S3/STS and identity provider such as MinIO S3 authenticating with MinIO STS and Keycloak (OIDC).


Refer to our S3 documentation.

SMB Protocol Support

SMB (Server Message Block) is used to access Windows File Shares or a Samba Linux Server. Cyberduck 8.7.0 adds support to access SMB shares as an light-weight, performant alternative to built-in support in macOS and Windows. Support in Mountain Duck is forthcoming in version 5.

Connecting to SMB

To connect to your SMB (formerly known as CIFS (Common Internet File System) server such as a NAS (Network Attached Storage) using NTLM authentication, select SMB (Server Message Block) in Open Connection or the Bookmark configuration. The default domain name is set to “WORKGROUP” and can be changed to meet the username format requirement depending on the server setup.

SMB Share

You will provided with a list of available shares from the server or alternatively if not supported prompted to input the share name manually. Specify the share name as a Path in the bookmark to avoid connect to a single share.

Up-to-date information about SMB interoperability can be found in out documentation.

Alternative to the official Dropbox client

Dropbox recently adopted the File Provider API available on macOS to be used as the exclusive way to synchronize files with their own app. The most prominent change from a user perspective is the limitation to store all synchronized files in ~/Library/CloudStorage as required by the File Provider API. Many users with large data sets preferred to set a custom location on an external disk previously which is no longer an option.

Use Mountain Duck instead of the official Dropbox client

Mountain Duck is a viable alternative to the official Dropbox client. It allows to connect to and synchronize your files in Dropbox without any additional bloat. In Mountain Duck Preferences, you can change your cache location to a different folder or even to an external drive.

Connecting to Dropbox

Mounting your Dropbox in Finder is straight forward using Mountain Duck:

  • Select Open Connection within the Mountain Duck dropdown menu
  • A new bookmark window will pop up
  • Select Dropbox from the protocol section on the top and choose Connect
  • Your web browser will open leading you through the authentication and authorization flow

Once successfully connected, your files from Dropbox will open in Finder. To connect to a single folder instead of the root, add a path to your bookmark configuration. Without adding a Path to the bookmark configuration, you will be connected to the root of your Dropbox.

Connect to multiple accounts

Connect to and work with multiple Dropbox accounts simultaneously. Repeat the above steps to connect to an additional Dropbox account you may have access. Open a new bookmark and login to the other Dropbox account in your web browser when authorizing access for Mountain Duck.

Use Cyberduck to retrieve files from Dropbox without syncing

Alternatively, use Cyberduck to browse your Dropbox without syncing the files to your computer.

Boxcryptor Alternative

Boxcryptor has been acquired by Dropbox and will terminate free accounts as of January 31, 2023. Till then, all users have to look for an alternative. It is not clear how customers with existing contracts are served in the future and no new accounts are accepted. So why not use Mountain Duck with support for the Cryptomator vault format independent from a single provider?

Smart Synchronization

Mountain Duck allows you to mount multiple cloud storages and servers as network drives on macOS and Windows using Smart Synchronization for offline access. Use the built-in, fully interoperable support for Cryptomator vaults to encrypt your sensitive data in password-protected vaults with end-to-end and zero-knowledge encryption. You do not need to have the Cryptomator apps installed but can access the same vault using Cryptomator for iOS for example.


Cryptomator is free and open-source software with no security by obscurity, no hidden backdoors from third parties, no need to trust anyone except yourself. No online services, no subscriptions, no accounts.


Follow these steps to migrate documents currently in Boxcryptor to a Cryptomator vault accessible through Mountain Duck:


Follow our documentation for step-by-step instructions to create a new vault or access an existing vault stored on your preferred cloud storage (including Dropbox).

Local Cache Size Limitation

Mountain Duck 4.12 introduces new settings to allow cache management — a top requested feature.

In Smart Synchronization connect mode all files you work with (e.g. open, save, upload or explicitly choose to keep offline) are saved in the local cache to shorten access times and to make them editable when offline. Depending on the size of your files, this might eat up your local disk space. This can be problematic in particular for computers with a small SSD disk. The new cache management feature gives you the ability to define a retention time for files and to limit the size of the cache in general. Both settings can be enabled either separately or in combination.

The first option defines the retention time in days after which a file is purged from the cache when it was not accessed during this period. The size option is a soft limit that does apply on a bookmark basis and excludes files marked to be kept offline by the user. In any case, older files are always purged first.

View and Retrieve Previous File Versions

Cyberduck 8.4 and Mountain Duck 4.12 revamp support to view and retrieve previous versions. Instead of the context menu, previous versions are now listed into the Versions tab of the Info window.

Using the buttons in the lower-left corner, you can perform different actions on the selected version:

  • Revert to this version
  • Delete the version permanently
  • View the version using QuickLook on macOS or open this version in the default editor application on Windows.

The versioning feature is now available for Amazon S3, Backblaze B2, Dropbox, Google Drive, Google Cloud Storage, Microsoft OneDrive, and Microsoft Sharepoint connections. You can find full interoperability information in the documentation available.