How to enable dual authentication factor in Zimbra (2FA)

How it works

The use of two-factor authentication to prove your users’ identity is based on the premise that an unauthorized actor is unlikely to be able to supply both factors required for access. If, in an authentication attempt, at least one of the components is missing or incorrect, the user’s identity is not established with sufficient certainty and access to the user Zimbra Mailbox being protected by two-factor authentication remains blocked.

How to enable two-factor authentication feature (User Web Client)

Once the Admin has been enabled and configured the 2FA, users will see a new option under Preferences > Accounts > Account Security, called Setup two-step authentication

If the user clicks on the Setup two-step authentication link, the configuration process will begin.

The first step shows a brief description about two-step authentication. The user must click on Begin Setup.

Next step will be introduce the user current password, if you remember the theory of 2FA, this will be “the component the user knows”. Once the user wrote the password, click on Next.

The next step retrieves the other component the user must have, in this case an app in the smartphone. The Two Factor authentication wizard will show a Wiki link with the OTP Apps Zimbra recommends to use.

Once the user has installed the App, the 2FA wizard will show a unique key that the user must enter in the Smartphone OTP App.

How to Install and Configure an OTP smartphone app

In this example, I will use Google authenticator, but please visit our Wiki where you can find other options. In the App Store or Play Store, search by Google authenticator, then click Install.

Once the app is installed, open it, and click Begin Setup.

The app will ask if you want to configure a Manual entry or Scan a barcode. Zimbra Collaboration 8.7 supports only manual entry for now. However, keep in mind the next Bug where it is being discussed to add the option to support barcodes.

To configure the App, the users must add an email address and the unique Key from the Zimbra Web Client.

All done! Now the app is configured and will show a 6-digit code that changes after 15 seconds.

File:Zcs87-2fa-014.png

Finishing the configuration in the Web Client

Once the user has the App configured and showing the 6 digit code, the user can enter the Code in the wizard window and click Next.

The two-step authentication feature is now enabled, and the user will be prompted for a code in each new Browser, smartphone, computer, or app where he or she tries to access the account.

In the users’ Preferences > Accounts > Account Security (if the Admin has enabled these options under the COS), the user will see more options like the one-time codes, Trusted devices, and Applications. as

Testing Zimbra Two-factor authentication

Testing a new Web Browser session in a new Computer

If the user now goes to another Web Browser, computer, smartphone, or if he or she tries to configure Zimbra Desktop, the user will successfully pass the two-factory authentication. For example on the Web Client: One-time Codes

With the two-factor authentication enabled, there may be a situation when the smartphone doesn’t have battery to answer the code challenge, or the device has been lost, etc. For cases like this, Zimbra introduces the One-time codes functionality. This function allow users to generate multiple codes to use in case of emergency. The total number of one-time codes can be configured by the Admin.

The user can click on the One-time codes View option to see the codes. The user must keep the codes secure (written somewhere, in another device, etc.).

Testing Zimbra Desktop with 2FA

• Pending

Testing Zimbra Connector for Outlook with 2FA

• Pending

Trusted Devices

Zimbra Web Client and Zimbra Touch Client can be specified trusted during the second stage of two-factor authentication. Once the computer/device is trusted user will only need to provide standard credentials, bypassing the two-factor code.

How to trust a computer/device

Once the user enters two-factor code in the login screen the user will have to select the check box Trust this computer and click Verify to trust the current computer/device. User can trust more than one computer/device.

How to revoke trusted computer/device

Once the user trust some computer/device user can revoke the trusted computer/device by navigating to Preferences > Accounts > Trusted Devices in Zimbra Web Client. User can revoke trust for the current device by clicking revoke this device link and all other trusted devices by clicking revoke all other devices link.

Application Passcode

Clients such as IMAP or ActiveSync do not support the UI flow needed for TOTP authentication. For these users need to generate application passcode.

Application passcodes:

• Randomly generated.
• Can be created by giving a label and revoked by their label.
• Changing account password will revoke all application passcodes.

How to create an application passcode

User can create an application passcode by navigating to Preferences > Accounts > Applications and selecting Add Application Code button. User can enter the application name in the Add Application Code dialog and click Next. Application passcode will get generated and it can be used to sign in to your account.

How to revoke an application passcode

Once the user generates application passcode user can revoke it by navigating to Preferences > Accounts > Applications in Zimbra Web Client. User can revoke this application passcode after selecting the required name in the list.