Strong Certificate Mapping for Intune PKCS and SCEP Certificates

Always On VPN LockDown Mode

With the October 2024 Intune update, Microsoft introduced support for strong certificate mapping for certificates issued by Intune via the Intune Certificate Connector. Enabling strong certificate mapping support in Intune is an important change for those organizations using Microsoft Intune to issue and manage certificates for their users and devices, as it resolves a critical implementation blocker.

Note: This post was updated to clarify that adding the {{OnPremisesSecurityIdentifier}} for PKCS certificates is not required. This variable is only used for SCEP certificates.

Background

In May 2022, Microsoft released security update KB5014754, which added functionality to domain controllers and enterprise issuing certification authority (CA) servers, allowing the Kerberos Key Distribution Center (KDC) to enforce strong certificate mapping. Specifically, with KB5014754 installed, issuing CAs now add the requesting principal’s Security Identifier (SID) to the certificate in a new certificate extension. Domain controllers can be configured to reject authentication requests using certificates that do not include this information.

Today, DCs with KB5014754 installed will still allow authentication without strong certificate mapping. However, Microsoft has stated they will begin enforcing strong certificate mapping in February 2025, with an option to disable it via the registry. Starting in September 2025, full enforcement will be mandatory.

Reference: https://support.microsoft.com/en-us/topic/kb5014754-certificate-based-authentication-changes-on-windows-domain-controllers-ad2c23b0-15d8-4340-a468-4d4f3b188f16

Limitation

The initial changes in KB5014754 applied only to online certificate templates, meaning those that build the subject name from Active Directory. However, deploying certificates with Intune using either PKCS or SCEP requires using an offline certificate template that allows the requestor to supply the subject name in the request. When using offline templates, a certificate is issued but does not embed the SID in the certificate. Using offline templates presents unique challenges to organizations moving to modern management with Intune and Entra ID.

Intune Changes

The October 2024 Intune update addresses this limitation by providing a method to include SID information in certificates using either SCEP or PKCS.

SCEP

To include the SID information in SCEP certificates, create or edit an existing SCEP device configuration policy and define a URI Subject Alternative Name (SAN) attribute with the value {{OnPremisesSecurityIdentifier}} as shown here.

PKCS

To include SID information in PKCS certificates, administrators must ensure the Intune Certificate Connector is updated to at least version 6.2406.0.1001. In addition, a registry setting must be enabled on the Intune Certificate Connector server.

On the server where the Intune Certificate Connector is installed, open the registry editor, navigate to HKLM\Software\Microsoft\MicrosoftIntune\PFXCertificateConnector, and change the value of EnableSidSecurityExtension to 1.

Optionally, administrators can update this setting at the command line by running the following PowerShell command.

Set-ItemProperty -Path ‘HKLM:\SOFTWARE\Microsoft\MicrosoftIntune\PFXCertificateConnector’ -Name EnableSidSecurityExtension -Value 1 -Force

Once complete, restart the Intune Certificate Connector server for the changes to take effect.

Certificates

SID information is added to certificates differently depending on which Intune device configuration policy type is used.

PCKS

PKCS certificates have the SID embedded in the certificate extension 1.3.6.1.4.1.311.25.2, as shown here.

SCEP

SCEP certificates have the SID embedded in the Subject Alternative Name (SAN) field in the format “tag:microsoft.com,2022-09-14:sid:<SID>” as shown here.

Migration

When making these changes to embed the SID in Intune-issued certificates in an existing Intune PKCS or SCEP configuration policy, the change will only affect certificates issued after the change is made. To update all certificate holders, you must create and deploy a new device configuration policy to targeted users or devices. Deleting the old profile (or ensuring it no longer applies) will remove the old certificate from the endpoint. If you’ve configured your Intune Certificate Connector to support revocation, the old certificate will also be revoked.

Entra Conditional Access

Entra Conditional Access certificates have included SID information since July 2023. More details here.

Intune Cloud PKI

The changes above will also work with certificates issued by Cloud PKI for Intune.

Other Cloud PKI Providers

Many other Cloud PKI providers, such as SCEPman and KEYTOS, already include the embedded SID in their certificates. Other cloud PKI providers may also include embedded SID. Consult your provider to confirm.

Additional Information

Microsoft Intune October 2024 Strong Certificate Mapping Update

Microsoft Intune Certificate Connector Strong Certificate Mapping Update for PKCS

Entra ID Conditional Access Certificates with SID Information Now Available

Implementing Strong Certificate Mapping in Microsoft Intune PKCS and SCEP Certificates

Certificate-Based Authentication Changes and Always On VPN

Free Entra Certificate-Based Authentication Training Course

I’m pleased to announce I’ll present a FREE online training course on Microsoft Entra Certificate-Based Authentication (CBA). The course will be delivered through the ViaMonstra Online Academy on Wednesday, November 6, beginning at 10:00 AM CST. Once again, this training course is entirely FREE, so don’t hesitate to register now! If you can’t attend the live session, you can always view the presentation recording later.

Course Highlights

Join me for this 90-minute live, online training session where you will learn:

  • How certificate-based authentication offers more robust protection than passwords alone and mitigates phishing and MFA bypass risks
  • How Entra CBA enables a seamless, passwordless user experience while maintaining high security and assurance
  • How Entra CBA eliminates the need for physical authentication devices such as FIDO keys or security tokens, reducing costs and complexity
  • How to configure and manage affinity binding and authentication strength policies for Entra CBA

When you attend the live event, you’ll have the opportunity to ask questions directly during the presentation, so be sure to register today and join us for this free training session!

Additional Information

Mini-Course – Microsoft Entra Certificate-Based Authentication

Microsoft DirectAccess Formally Deprecated

Today, Microsoft has announced the formal deprecation of DirectAccess. Microsoft DirectAccess is a widely deployed enterprise secure remote access solution that provides seamless, transparent, always-on remote network connectivity for managed (domain-joined) Windows clients. First introduced in Windows Server 2008 R2, it’s been a popular solution with many advantages over ordinary VPN technologies of the past.

Windows Server 2012

DirectAccess was almost entirely rewritten in Windows Server 2012. Many of the features and enhancements offered for DirectAccess with the Unified Access Gateway (UAG – a separate product with additional costs) were built into the operating system directly. In addition, Microsoft introduced integrated load balancing and geographic redundancy features.

Demise of DirectAccess

DirectAccess relies heavily on classic on-premises technologies like Active Directory. All DirectAccess servers and clients must be joined to a domain. In addition, all DirectAccess clients must be running the Enterprise edition of Windows. With organizations rapidly adopting cloud services such as Azure and Entra ID, Microsoft began to develop an alternative solution that better integrated with the cloud. That solution is Always On VPN. With that, Microsoft stopped developing DirectAccess after the release of Windows Server 2012 R2. No new features or capabilities have been added to DirectAccess since that time.

Deprecation

We’ve been speculating about the end of life for DirectAccess for quite some time now. However, this formal deprecation announcement from Microsoft is official. It is the end of the road for this technology. To be clear, though, DirectAccess is available today in Windows Server 2022 and Windows 11. DirectAccess will be included in the upcoming release of Windows Server 2025. However, formal deprecation from Microsoft means they will remove DirectAccess components from the next release of the operating system.

What Happens Now?

Organizations should begin formal planning efforts to migrate away from DirectAccess. Here are a few popular solutions to consider.

Always On VPN

Always On VPN is the direct replacement for DirectAccess. It was designed to provide feature parity for DirectAccess, with seamless, transparent, always-on remote network connectivity. However, Always On VPN better integrates with Entra ID and supports conditional access. It does not require domain-joined devices or servers and works well with cloud-native endpoints. Always On VPN is a good choice for organizations that employ hybrid Entra-joined devices.

Entra Private Access

Entra Private Access, part of the Entra Global Secure Access suite, is an identity-centric zero-trust network access (ZTNA) solution from Microsoft. It is in public preview now and has some compelling advantages over traditional VPNs. However, Entra Private Access is not feature complete today. In addition, it is best suited to cloud-native (Entra-joined only) endpoints.

Absolute Secure Access

Absolute Secure Access (formerly NetMotion Mobility) is a premium enterprise remote access solution with many advanced options. It is by far the best solution on the market today. Absolute Secure Access is a software solution that supports zero-trust configuration and includes many features to improve and enhance security, performance, and visibility. In addition, it provides cross-platform support, including Windows, macOS, iOS, and Android operating systems.

Learn More

We have several decades of experience working with secure remote access technologies. We can help you and your organization find the best solution for your needs. Fill out the form below for a free one-hour consultation to discuss your DirectAccess migration strategy today.

Additional Information

Deprecated Features for Windows Client