Configure Agentless Desktop Single Sign-on - new implementations
Desktop Single Sign-on (DSSO) is the functionality that allows users to be automatically authenticated by Okta, and any apps accessed through Okta, whenever they sign-in to your Windows network. It provides a superior user-experience as users don’t have to sign in multiple times.
Traditionally, enabling Desktop SSOAn acronym for single sign-on. In a SSO system, a user logs in once to the system and can access multiple systems without being prompted to sign in for each one. Okta is a cloud-based SSO platform that allows users to enter one name and password to access multiple applications. Users can access all of their web applications, both behind the firewall and in the cloud, with a single sign in. Okta provides a seamless experience across PCs, laptops, tablets, and smartphones. required deploying IWA agents. Agentless desktop SSO eliminates the need to deploy IWA agents across Active DirectoryActive Directory (AD) is a directory service that Microsoft developed for the Windows domain networks. It is included in most Windows Server operating systems as a set of processes and services. Initially, Active Directory was only in charge of centralized domain management. domains to enable DSSO. This enables you to have no maintenance overhead and also removes the burden of worrying about High Availability as Okta handles the KerberosKerberos is a computer-network authentication protocol that works on the basis of tickets to allow nodes communicating over a non-secure network to prove their identity to one another in a secure manner. validation. Diagram
As you configure Desktop SSO (on prem or agentless) in your environment, be aware of how the Desktop SSO flow works when importing users and how Just in Time (JIT) authentication will occur.
- If using on-prem DSSO IWA always sends Okta the Universal Principal Name (UPN). This is the only data Okta uses to look up a user. Okta does not perform authentication for users because Kerberos validation is already done on the IIS side.
If using Agentless Desktop SSO, your web browser sends the Kerberos ticket to Okta, and relies on the AD agentA software agent is a lightweight program that runs as a service outside of Okta. It is typically installed behind a firewall and allows Okta to tunnel communication between an on-premises service and Okta's cloud service. Okta employs several agent types: Active Directory, LDAP, RADIUS, RSA, Active Directory Password Sync, and IWA. For example, users can install multiple Active Directory agents to ensure that the integration is robust and highly available across geographic locations. to look up the UPN. The Kerberos validation is now done in the cloud in Okta.
When a user tries to sign in using Desktop SSO:
- If the user is already imported and active in Okta: Okta uses the UPN to look up the user. If Okta finds the user, the profile reloads from AD and the user signs in.
- If the user is imported but not yet active in Okta: Okta uses the UPN to look up the user. If Okta finds the user, the profile loads from AD, is activated and the user signs in.
- If the user has not been imported into Okta and JIT is on: Okta can only validate the user by the UPN. So the Okta user name format must be the UPN in order for the user to be successfully imported with JIT turned on. If the user name format is something other than the UPN, for example the email address or SamAccountName, the search will fail to locate the user.
- If the user has not been imported into Okta and JIT is off: User sign in will fail.
- Custom URL —
If you are using a custom URL:
- Agents – Use the actual domainA domain is an attribute of an Okta organization. Okta uses a fully-qualified domain name, meaning it always includes the top-level domain (.com, .eu, etc.), but does not include the protocol (https). (example.okta.com) and not the custom domain (example.customname.com).
- IWA SSO – Modify the web.config file to include the custom url.
- Agentless DSSO – Make sure that all sign-in flows and browser bookmarks use the correct URL.
- Using AES128 or AES256 encryption — If you want to use AES128/256 with Agentless Desktop SSO or MS AppAn abbreviation of application. Essentially, it is a web-based site used to perform any number of specific tasks, and requires authentication from end users by signing in. silent activation, you must enable AES for both the AD domain as well as the service account for Okta DSSO. If it isn't enabled for the AD domain you will see a Kerberos error KDC_ERR_ETYPE_NOTSUPP in the Kerberos events.
For details on how to enable each of these, refer to Windows Configurations for Kerberos Supported Encryption Type.
You have an Active Directory domain (or multiple domains) integrated with your Okta orgThe Okta container that represents a real-world organization..
You have permissions in Active Directory to configure a Service Principal Name (SPN). For more info on permissions, see Delegating Authority to Modify SPNs at the following URL: https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/cc731241(v=ws.11).
- You will need to create a service account, as described below. For this service account:
- A domain user account is recommended, for the Okta tenant Kerberos service, instead of a domain adminAn abbreviation of administrator. This is the individual(s) who have access to the Okta Administrator Dashboard. They control the provisioning and deprovisioning of end users, the assigning of apps, the resetting of passwords, and the overall end user experience. Only administrators have the Administration button on the upper right side of the My Applications page. account as a security best practice.
- To further lock down the account, the logon to restriction can be turned on with a fictitious host name, and the account can be marked as Account is sensitive and cannot be delegated. This is also for security reasons.
- Agentless DSSO will not work if a single user has memberships to more than 600 security groupsGroups allow you to organize your end users and the apps they can access. Assigning apps to large sets of end users is made easier with groups. — If an end user tries to go through the Agentless DSSO flow and has more than 600 security groups, they will see a 400 response and be redirected to the regular sign in page.
- The following browsers are not supported:
- Firefox on Windows
- Chrome on macOS.
- MS Edge
- If you are using Windows functional level 2008 or below, be aware that it uses a less secure encryption RC4. We recommend that you upgrade to at least Windows functional level 2008 or above to use the most secure encryption algorithm.
- When re-enabling Agentless DSSO, Identity Provider (IDPAn acronym for Identity Provider. It is a service that manages end user accounts analogous to user directories such as LDAP and Active Directory, and can send SAML responses to SPs to authenticate end users. Within this scenario, the IdP is Okta.) routing rules must be manually reactivated.
Setting up Agentless Desktop SSO involves the following steps:
- Create a service account and configure an SPN
- Configure Browsers on Windows or Mac
- Enable Agentless Desktop SSO
- Update the default DSSO Identity Provider routing rule
- Validate Agentless Desktop SSO
- Steps that may apply to your environment:
Complete the procedures in the order they are presented.
In order for Okta to negotiate Kerberos authentication for Agentless Desktop SSO, you will need to create a new service account and set a Service Principal Name (SPN) for that service account.
- Sign in to a server from which you can access Active Directory Users and Computers.
- Create a new account with the following properties. The service account itself does not need admin permissions, but you will need specific permissions to set an SPN as mentioned in Delegating Authority to Modify SPNs
User logon name: <username>
User logon name (pre-Windows 2000) : <username>
where <username> is any username of your choice.
Select a password and set to Password never expires.
In a command window configure an SPN for the service account using the following syntax:
setspn -S HTTP/<myorg>.kerberos.<okta|oktapreview|okta-emea>.com <ServiceAccountName>>
Where HTTP/<myorg>.kerberos.okta.com is the SPN. <ServiceAccountName> is the value you used when configuring the Early AccessEarly Access (EA) features are opt-in features that you can try out in your org by asking Okta Support to enable them. Additionally, the Features page in the Okta Admin Console (Settings > Features) allows Super Admins to enable and disable some EA features themselves. version of Agentless DSSO and <oktaorg> is your Okta org (either oktapreview, okta-emea or okta). For example,
setspn -S HTTP/atko.kerberos.oktapreview.com atkospnadmin.
The next step is to configure your browsers.
Configuring changes on Internet Explorer (IE) will be enough as Chrome will recognize these settings.
Note: Firefox and Edge are not supported.
There are three main steps involved in configuring the browsers on Windows:
- Enabling IWA on the browsers.
- Adding Okta to the local intranet in Internet Explorer (IE). The Okta URLs must include https://<myorg>.kerberos.okta.com.
- Creating a GPO to apply these setting across all our clientEssentially, a client is anything that talks to the Okta service. Within the traditional client-server model, Okta is the server. The client might be an agent, an Okta mobile app, or a browser plugin. machines.
To configure your browsers:
- Enable IWA on the browsers:
- In Internet Explorer select Tools > Internet Options.
- Click the Advanced tab, scroll down to the Security settings, and select Enable Integrated Windows AuthenticationAuthentication is distinct from authorization, which is the process of giving individuals access to system objects based on their identity. Authentication merely ensures that the individual is who he or she claims to be, but says nothing about the access rights of the individual. Authentication methods and protocols include direct auth, delegated auth, SAML, SWA, WS-Fed, and OpenID Connect..
- Click OK.
Note: Make sure that Internet Explorer can save session cookies (Internet Options > Privacy tab). If it cannot, neither SSO nor standard sign in can work.
- Configure the Local Intranet Zone to trust Okta:
- In IE, open Options > Security.
- Click Local Intranet > Sites > Advanced and add the URL for your Okta org as configured in earlier steps. For example: https://<myorg>.kerberos.okta.com.
- Click Close and OK on the other configuration options.
- Create a GPO to roll this out to all client machines that will use Agentless DSSO.
Agentless Desktop SSO is currently not supported on Chrome on macOS.
DSSO is enabled automatically in Safari on OS/X. Make sure that the macOS host is a Windows domain member. For how to add your Macintosh OS/X host to a Windows domain, see the article macOS Sierra: Join your Mac to a network account server.
Agentless Desktop SSO is currently not supported on Chrome.
You can enable Agentless Desktop SSO for testing or for production.
- Test — allows you to test by signing in using the direct Agentless DSSO endpoint URL:
- On — allows end usersEnd users are people in your org without administrative control. They can authenticate into apps from the icons on their My Applications home page, but they are provisioned, deprovisioned, assigned, and managed by admins. to sign in from the default sign in endpoint, routing through the Agentless DSSO sign in endpoint. The end user doesn't need to explicitly type in the DSSO URL.
- On the Okta Admin Console, click Security > Delegated Authentication.
- Scroll to Agentless Desktop SSO.
- Click Edit and select a Desktop SSO mode:
- Test — For testing in your Preview environment.
- On — For enabling SSO in Production.
- For Allowed network zones, add the zones that are associated with the machines from which you will be implementing Agentless SSO.
Note: If IdP Discovery is turned on, the network zone options will not be available. When IdP Discovery and Agentless DSSO are both on, Agentless DSSO network zones are controlled through the IdP Routing Rules. You will update the default IdP routing rule in Update the default DSSO Identity Provider routing rule .
- In AD Instances, select the Active Directory instance on which you configured the SPN.
- Complete these fields to configure Agentless Desktop SSO for the selected Active Directory domain:
Desktop SSO — Select Enabled or Disabled depending on whether you are enabling for production or testing.
Service account username — This is the AD sign-on name that you created in Create a service account and configure an SPN above, without any domain suffix or Netbios name prefix. It can be the sAMAccountName or the username part of the UPN. These two may be the same string unless the Org admin chose to use different values.
This field is case sensitive. When the UPN prefix differs from sAMAccountName, the service account username needs to be the same as the UPN and include the domain suffix. For example, agentlessDsso@mydomain.com.
Service account password — Password for the account that you created in AD.
- Validate service account credential on save — (Optional) Validates the service account credentials as an optional step in saving the Kerberos realm configuration. If it's checked, the service account will be authenticated by the AD agent. If the credentials cannot be validated, an error message appears. If you don't want to validate or can't because the AD agent isn't responsive, the box can be unchecked to skip the validation.
- Click Save. Once a domain has been configured and enabled, users can sign in with Agentless DSSO.
To complete this step you must already have an Identity Provider configuration.
After you turn on Desktop SSO, a default DSSO routing rule is created. You must configure the network information for this rule.
- Click Security > Identity Providers > Routing Rules.
- Select the Default Route to AgentlessDSSO rule. By default the network information is not configured and the rule is Inactive.
- Click Edit.
- Indicate your routing specifications.
- User's IP is: Select Anywhere to apply the rule to any user location, select In zone to apply the rule to a specific zone, or select Not in zone to apply the rule to users outside of a specific zone. For information on zones, see IP Zones.
- User's device platform is: Select Any device to apply the rule to users with any device type, or to apply the rule to users with specific devices, select Any of these devices and select specific devices.
- User is accessing: Select Any application to apply the rule when a user accesses any application, or to apply the rule when a user accesses specific applications, select Any of the following applications and enter an application name.
- Use this identity provider: Select AgentlessDSSO.
- Click Update Rule to save your changes.
- Click Inactive, Activate, and then Activate in the Activate Rule dialog box to activate the rule.
The next step is to verify that Agentless DSSO is configured correctly.
After configuring Agentless DSSO, you can verify that everything is correctly configured by doing the following:
- Sign in to a domain-joined, on-network device that is joined to the Active Directory environment on which you have enabled Agentless Desktop SSO. Ensure that you are logged in as a user that is already active in Okta.
- If you haven’t already, add your Okta environment to your Local Intranet settings.
- In a browser, open Options > Security.
- Click Local Intranet > Sites > Advanced and add the URL for your Okta org as configured in earlier steps. For example, https://<myorg>.kerberos.okta.com.
- Click Close and OK on the other configuration options.
- On a Windows machine, sign into your Okta org. If Agentless DSSO is configured correctly, you will be automatically redirected to your end user apps dashboard without entering any credentials.
- Verify in the system log that the user authenticated through Agentless Desktop SSO. In your Okta org, you will see an entry for Authenticate user via IWA with no entries referring to an on-prem IWA server.
Procedures that may apply to your environment
Okta recommends that you test the Agentless DSSO changes in a limited scopeA scope is an indication by the client that it wants to access some resource. before rolling out widespread changes to your org.
To test Agentless DSSO, follow these general steps:
- Create a service account and configure an SPN
- Perform the steps in Configure browsers for SSO on Windows and Configure browsers for SSO on Mac as appropriate.
- Enable Agentless Desktop SSO in test mode
- Optional — Enable Kerberos event logging. For more information, see https://support.microsoft.com/en-us/help/262177/how-to-enable-kerberos-event-logging.
- Validate Agentless Desktop SSO
by signing in using the direct Agentless DSSO endpoint URL:
If Agentless DSSO is configured correctly, you will be able to sign in without being prompted for credentials. If you experience problems signing in, ensure you have completed all the steps listed above. You can check the Troubleshooting section for additional help.
You may want to have a back up plan in the event that Agentless DSSO fails. There are two fail over options:
- Okta will automatically fail over to the default sign-in page.
- You can use on-prem IWA DSSO as a backup.
Choosing to fail over to on-prem IWA DSSO, requires you to install and configure the on-prem IWA DSSO. If on-prem IWA DSSO is configured and enabled, it will automatically take over if Agentless DSSO stops working. For details, see Install and configure the Okta IWA Web agent for Desktop Single Sign-on.
If you have trouble after enabling the registry changes you can roll back the registry key changes you've made.
To roll back the registry settings using the GPO, simply edit the previously added registry keys changing the action item from Create to Delete.
Can I run Agentless DSSO and IWA Web App for Desktop SSO at the same time?
Yes. When both are enabled and the user tries to sign in, Okta first tries authenticating against Agentless DSSO and if that fails, it falls back to the on-prem IWA server.
Can I use Agentless DSSO while remote?
No. You need to be on-network to sign in through Agentless DSSO. However if using a VPN, Agentless DSSO will work.
Do I need to open any special ports for this to work?
Do computers need to be domain joined?
Yes. In order for Agentless DSSO to work, the computer needs to be domain joined.
Do I need to install an agent on my machines?
No. Agentless DSSO removes the need to have any IWA agents on your machines. Instead the Kerberos validation is done on Okta's servers.
When troubleshooting I see a 401 error from Okta, does this mean something is failing?
No that's expected. When the end user goes to the browser and types in <myorg>.okta.com, Okta sees your org has Agentless DSSO enabled and kicks off a 401 authenticate challenge to your KDC which then returns a Kerberos ticket back to Okta.
Can I recreate re-write rules?
Does my UPN domain name suffix need to be the same as the AD domain’s primary DNS suffix?
No. Okta uses the user SID to locate and authenticate the user. So it shouldn't matter if they don't match because the request resolves to the user object using SID.
Does Agentless DSSO have any rate limits?
The current rate limit for the Agentless DSSO endpoint /login/agentlessDSSO is 1000/minute. This is double the on-prem rate limit as described in Concurrent Rate Limits because each successful login performs two http commands to the Agentless DSSO endpoint. The number of successful logins per minute will be the same as on-prem IWA.
With Agentless DSSO enabled, you browse to your Okta tenant and see the regular sign in page.
You were not routed to the Agentless DSSO endpoint. Confirm your IP address is added to the correct zone and that zone is used for the Agentless DSSO.
I am working remote and Agentless DSSO doesn't work.
In order for Agentless DSSO to work your browser must be able to connect to the Key Distribution Center (KDC) on your domain. This is crucial to the Kerberos validation. If you are unable to reach the KDC you will not obtain a Kerberos ticket and will not be able to authenticate. If available, join your network through a Virtual Private Network (VPN). If the KDC is available through the VPN, Agentless DSSO will work.
I am in the right zone and on-prem and Agentless DSSO still fails.
Confirm the username and password are correct for the SPN account both in AD and as stored in the Okta configuration. If the account expired or was changed it will break the flow.
I have verified I am in the correct zone, verified the account used for the SPN is correct, I am on-premises and Agentless DSSO still fails.
This could suggest some type of Kerberos failure. Using tools such as Wireshark, capture your network traffic during your Agentless DSSO attempt. Once captured, filter for Kerberos traffic. Compare this traffic to the Event Viewer logs on your KDC. Using these two tools (or similar) you should be able to uncover Kerberos failures.
Note: In order to see debug-level Kerberos events you may need to enable Kerberos event logging. For more information, see https://support.microsoft.com/en-us/help/262177/how-to-enable-kerberos-event-logging.
Kerberos validator and sign in failure
If the clock skew between your corporate network and Okta Agentless SSO becomes too great, Kerberos validation and sign in will fail. This issue will not occur if your domain controller's clock is synced to an external time server.
Slow or failed sign-on experience
During Agentless DSSO sign-in Okta does a SID look-up. During the EA time frame this is being done with a call to the AD Agent. If you experience a slow sign-in experience or failed sign-ins consider increasing the number of polling threads for your AD Agents or adding new AD Agents for your domains. For details on how to do this, see Install multiple Okta AD agents and Change the number of Okta Active Directory (AD) agent threads.
If this occurs, you will see the AD Agent logs filled with a large number of read LDAPLightweight Directory Access Protocol (LDAP) is a lightweight client-server protocol for accessing directory services, specifically X.500-based directory services. LDAP runs over TCP/IP or other connection oriented transfer services. calls, without any Next action = NONE lines shown. For example:
2018/06/11 23:14:34.441 Debug -- N079-H076(57) -- Sending result for READ_LDAP action (id=ADS2n15k1yGW23cn10g7) finished, (executionTime=00:00:00.2196026)