How to enable Single Sign-On for my Terminal Server connections

How to enable Single Sign-On for my Terminal Server connections

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Note: This post was updated on March 12, 2009, to include the latest information. 

What is Single Sign-On?

When applied to Terminal Services, Single Sign-On means using the credentials of the currently logged on user (also called default credentials) to log on to a remote computer. If you use the same user name and password logging on to your local computer and connecting to a Terminal Server, enabling Single Sign-On will allow you to do it seamlessly, without having to type in your password again.

Locally logged on credentials are used for connecting to TS Web Access, however, they cannot be shared across TS Web Access and TS or TS Gateway. Thus you will need to enable the Group Policy settings described below in order to use locally logged on credentials for TS or TS Gateway connections.

How to enable Single Sign-On?

Single sign-On can be enabled using domain or local group policy.

  1. Log on to your local machine as an administrator.
  2. Start Group Policy Editor - "gpedit.msc".
  3. Navigate to "Computer Configuration\Administrative Templates\System\Credentials Delegation".
    Group Policy Editor
  4. Double-click the "Allow Delegating Default Credentials" policy.
  5. Enable the policy and then click on the "Show" button to get to the server list.
    Group Policy 
  6. Add "TERMSRV/<Your server name>" to the server list. You can add one or more server names. Using one wildcard (*) in a name is allowed. For example to enable Single Sign-On to all servers in "MyDomain.com" you can type "TERMSRV/*.MyDomain.com". (Notice the "Concatenate OS defaults with input above" checkbox on the picture above. When this checkbox is selected your servers are added to the list of servers enabled by OS by default. For Single Sign-On this default list is empty, so the checkbox has no effect.)
    Group Policy Value
  7. Confirm the changes by clicking on the "OK" button until you return back to the main Group Policy Object Editor dialog.
  8. At a command prompt, run "gpupdate" to force the policy to be refreshed immediately on the local machine.
  9. Once the policy is enabled you will not be asked for credentials when connecting to the specified servers.

What are the limitations when using Single Sign-on?

  • Single Sign-On works only when connecting from an XP SP3, Vista or a Windows Server 2008 machine to a Vista or Windows Server 2008 machine. Please see this KB article about enabling CredSSP on XP SP3 which is required for Single Sign-On.
  • If the server you are connecting to cannot be authenticated via Kerberos or SSL certificate, Single Sign-On will not work. You can circumvent this restriction by enabling "Allow Default Credentials with NTLM-only Server Authentication" policy, which is less secure. (NTLM-only Server Authentication is less secure compared to using Certificates or Kerberos.)
  • If you have saved credentials for the target machine they take precedence over the current credentials.
  • Single Sign-On works only when using domain user accounts. Please see section below regarding user experience for non-domain clients.
  • If the Terminal Server connection is configured to go through a TS Gateway server then in some cases the settings of the TS Gateway server can override the TS Single Sign-on setting.
  • If the terminal server is configured to Always prompt or RDP file setting Always prompt, then Single Sign-on to TS will not work.
  • Single Sign-on only works with Passwords. Does not work with Smartcards.

Why is Single Sign-On controlled by Group Policy?

As a part of the logon process TS Client sends the actual user credentials (user name and password) to the server. If a code running as a regular user were allowed to enable Single Sign-On, any malicious software (virus, Trojan, spyware etc.) running in the user's session would be able to send the user's password to any machine on the network. So, only administrators should be allowed to decide which servers are safe for Single Sign-On.

Thus Single Sign-On can only be enabled on domain-joined client machines.

What if I have Single Sign-On enabled but want to use different credentials this time?

Start TS Client. Click the "Options" button. Select the "Always ask for credentials" checkbox. You will be asked for credentials next time you connect.

TS Client

How do I enable Single Sign-on for TS Gateway Server?

  1. On a Vista machine open up the "Group Policy Object Editor" by entering "gpedit.msc" at a command prompt.
  2. Navigate to "User Configuration", "Administrative Templates", "Windows Components", "Terminal Services", "TS Gateway" and select the "Set TS Gateway server authentication method" setting:
    Group Policy Editor
  3. Select the "Enabled" radio button.
  4. Under "Set TS Gateway server authentication method", click on the combo-box and select "Use locally logged-on credentials".
  5. If you want the users to be able to override this authentication method then select "Allow users to change this setting" checkbox.
    Group Policy
  6. Confirm the changes by clicking on the "OK" button until you return back to the main Group Policy Object Editor dialog.
  7. At a command prompt, run "gpupdate" to force the policy to be refreshed immediately on the local machine.
  8. Start up the TS client and navigate to "Options", "Advanced", click on "Settings" under "connect from anywhere". You should see the status text indicate the following: "Your Windows logon credentials will be used to connect to this TS Gateway server".
    image
  9. That's it! The client will now be able to connect to the gateway server ("gateway.microsoft.com" in the above example) using locally logged on credentials. Of course, if you want to use another set of credentials, you should select the "Allow users to change this setting" checkbox in the Group Policy Editor in Step-5 to bypass using the locally logged on credentials.

What if I am connecting from a non-domain joined client machine?

If you have a non-domain client, then you cannot get single sign-on by using locally logon credentials to authenticate with TSG and TS since administrator cannot deploy single sign-on group policies to the non-domain client machines.

Thus, to provide the best connection experience for non-domain clients through TS Gateway, set the option “Use my TS Gateway credentials with remote server option” in RDP file or in the mstsc client advanced setting menu as per screenshot below. This will ensure that end users are prompted for credentials only once during the connection experience.

 

image

Can the user get Single Sign-On experience when logging on using a Smart Card?

No. Unfortunately if a Smart Card is used to log on locally to the machine, these credentials cannot be used for Single Sign-On. Please also note that you cannot save Smart Card credentials in TS connections either.

Leave a Comment
  • Please add 7 and 1 and type the answer here:
  • Post
  • Can we get SSO on a thin client with windows XP SP3 embedded?

    I have a Session broker with NLB and I keep getting double prompts and on remote apps although I have setup credssp I am still being asked for a prompt. Is there something different I need to do for getting SSO on remote apps? I am doing all this on XP SP3 (standard) and later.

    TS and SSB are windows 2008 R2.

    TIA.

  • I cannot get this work with my Vista x64

    When I enable this policy, I can see registy:

    HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Policies\Microsoft\Windows\CredentialsDelegation

    I think this is wrong place. Should not be under wow6432Node?

    Anybody lucky with x64 OS?

  • Sorry, Not Vista, I have Windows 7

  • Dah, it did work. I just forget that I need use full domain name to connect.

  • why is this not working for me???  i have added the reg values and still get prompted for credentials when i click the .rpd remote app icon.  xp-sp3

    am i missing something else??

  • GOT IT!

    ...darn quotes...

    THANKS FOR THIS POST!

  • Is there a utility which can APPEND these values on XP SP3 platform which can be deployed via. GPO? Quite tricky going to 25x PCs to manually edit, and if I roll out a reg key, it will REPLACE the data, and I might replace something that I didn't know was there in the first place.

  • I have a 4 node RDS farm, 2 host , 1 broker and 1 web. My users use the web   http:\\myserver.local\rdweb to connect to thier applications. When I try the above settings, they are still prompted for user/pass. Is there more to do for this type of connection?

  • Hi,

    I have 02 disjoint domains, I want to provide  SSO to users from one the domain when accessing TSE to the other domain. In this case how can I do?

    Regards

  • Here is another resource with interesting tips on configuring terminal services:

    www.ericom.com/Configuring-Terminal-Services-Access.asp

    There is also information on load balancing.

  • Can someone tell me a script to enable this setting

    I am able to add the registry in via reg add however the settings it not enabled when i go into gpedit.msc on the local machine

  • > Single Sign-on only works with Passwords. Does not work with Smartcards

    Is this statement still valid? For Windows 8 / Server 2012 in particular?

    Ben,

    > I am able to add the registry in via reg add however the settings it not enabled when i go into gpedit.msc on the local machine

    If you change the registry using Regedit  or REG command, it could not appear in policy settings. Group Policy has its own database, and it is not refreshed automatically when a registry value get changed.

  • > Single Sign-on only works with Passwords. Does not work with Smartcards

    Is this statement still valid? For Windows 8 / Server 2012 in particular?

    Yes, this statement is still valid for Windows 8  and Server 2012.

  • Hi there does this apply to 2012 r2

  • Yes, the same applies to 2012 r2

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