SecSign ID Plugin: Windows Remote Desktop

This article gives an overview of securing your Remote Desktop Login with two-factor authentication. For a detailed tutorial on how to integrate two-factor authentication with your Remote Desktop setup, have a look at the plugin tutorial.

The following video gives an overview on the authentication process. The complex process can easily be integrated in a few simple steps.

With the SecSign ID Two-Factor Authentication the user can log in to Remote Desktop in just one convenient and quick step – without inconvenient and complex codes.
To login the user simply needs to provide user credentials like he is used to, and select the displayed symbol in his mobile app – that’s it. Next level security with minimal complexity.

If required you can choose mobile or Email OTP (one-time passwords) as alternative authentication option.

With SecSign enrollment of your users is quick and convenient for both the user and the administrator.

You have several options to enroll your users for 2FA with SecSign. Most commonly, the 2FA ID should be identical to the Windows user name (for example sAMAccountName or userPrincipalName), and only successfully authenticated (user name and password) users should be able to create a 2FA account.
SecSign offers several options to achieve a default 2FA activation and link of the 2FA with the AD user. The two most popular are described below.

With Schema Extension to add a 2FA attribute to the user in the Active Directory, or without Schema Extension and read-only access from the SecSign ID Server.

For both options the enrollment procedure can either proceed via the Custom ID App or a custom landing page for the users to enroll.

An overview on how the Active Directory can be integrated with you 2FA setup is available here.

Windows Login: Prerequisites

The SecSign ID Credential Provider looks up the SecSign ID user name of a Windows user in the Active Directory of the Windows domain. If the user is not yet associated with an ID, he is prompted to create one either manually, or by being automatically redirected to the onboarding website. The following pre-requisites need to be fulfilled:

• The PC on which the credential provider is install must be member of a Windows domain and
• Active Directory Configuration

In some cases the Active Directory needs to be connected with the SecSign ID On-premise server. To realize the following situations a connection must be established:

• If the SecSign ID should match the Windows user name. This can be realized during the enrollment with the Active Directory.
• If the SecSign ID should not match the Windows user name. This can be realized both with and without Active Directory schema extension. With an Active Directory Schema Extension the plugin receives the ID from the AD. If no Active Directory Schema Extension is set up, the plugin can store the users ID.
• If the 2FA should only be activated for specific Active Directory groups or IP ranges. This setting can either be activated in the plugin or in the Active Directory. The Active Directory needs to be connected to the on-premise server if the settings are defined via the AD. A connection is also required if selective 2FA should be centrally activated for several plugins at once.

All Windows Plugins are available as a MSI for a convenient and quick install

2FA for MS Remote Desktop Web Access

Microsoft’s Remote Desktop Web Access service allows to run published Windows applications from a browser. If the SecSign ID log-in has been added to the RD Web Access site then after the usual log-in with Windows user name and password a second page asks for confirmation of the log- in using SecSign ID:

MS Remote Desktop Web Access: Installation

Log-in using a domain administrator account an the Windows Server which has the RD Web Access role. Then run SecSign-RD-WebAccess-Setup.exe:

After installing the SecSign ID plug-in for Microsoft Remote Desktop Gateway the shared secret has to be copied there. The SecSign ID RD Web Access plug-in uses the secret to sign a gateway access token which it inserts into the RDP files of each published application. The SecSign ID RD Gateway plug-in will validate the signature using the same secret.

Finally, open your RD Web Access URL in a browser, log-in using your Windows user name and password and test the SecSign ID log-in. If anything fails the Windows Event Log will contain more information in Windows Logs → Application with the source SecSign ID RD Web Access.

2FA for Microsoft Remote Desktop Gateway

The SecSign ID log-in integration into RD Web Access alone only protects the RD Web Access log-in in a browser. A user who knows the necessary details to create an RDP file could log-in directly at the RD Gateway using the Remote Desktop Client. Furthermore, users could download RDP files generated by RD Web Access and use them again later without logging in at the RD Web Access site again.

The SecSign ID PAA (pluggable authentication and authorization) plug-in for Microsoft’s Remote Desktop Gateway prevents the aforementioned unwanted direct log-ins at the RD Gateway. To achieve this, the SecSign ID plug-in validates the signature of the gateway access token which has been inserted into the RDP file by the SecSign ID RD Web Access plug-in after a successful SecSign ID log-in at the RD Web Access site using a browser.

• Log-in using a domain administrator account an the Windows Server which has the RD Gateway role.
• Run SecSign-RD-Gateway-Setup.
• Run regedit.exe.
• Open HKEY_LOCAL_MACHINE\SOFTWARE\SecSign\RDGatewayAuthentication.
• SharedSecretWithRDWebAccess has to contain exactly the same 64 bytes as the respective
  value SharedSecretWithRDGateway in the adjacent registry key RDWebAccess.
• AccessTokenMaxAgeSeconds defines for how many seconds after a RD Web Access log-in the generated RDP files are allowed to run the published applications. The remote desktop client’s connection to the RD session host remains open for a certain time. During this time the opening of published applications is still possible even if AccessTokenMaxAgeSeconds has expired already. A user may always generate fresh RDP files by reloading the RD Web Access page in his browser. Only someone you downloads and copies an RDP file cannot use it after the RD Web Access log-out or on another computer when AccessTokenMaxAgeSeconds has expired.

The Windows Event Log will contain information about SecSign ID log-ins in „Windows Logs → Application“ with the source „SecSign ID RD Gateway“.

For more information about the individual Windows Plugins select your user case below.