Always On VPN and the PSPKI PowerShell Module

Certificates are a crucial part of a secure Always On VPN implementation. Certificates are phishing-resistant forms of authentication that, when configured correctly, provide robust and multifactor authentication for remote access users and devices.

AD CS

Most commonly, certificates are issued by an on-premises Microsoft Active Directory Certificate Services (AD CS) server. Administrators configure and deploy a Certification Authority infrastructure to issue and manage user and device authentication certificates in their organization. CA certificates are also required on the VPN server to support Always On VPN device tunnel connections and IKEv2 user tunnel connections. The NPS server also requires an enterprise CA certificate. Of course, the CA can issue certificates for other purposes, including Wi-Fi authentication, document signing, and code signing, just to name a few.

PSPKI

PSPKI is a PowerShell module available in the PowerShell Gallery for configuring, managing, and troubleshooting Microsoft AD CS. Created by Vadims Podans of PKI Solutions, PSPKI includes over 100 functions for various AD CS and certificate-related tasks. Always On VPN administrators will find this PowerShell module helpful when configuring and troubleshooting certificate-related issues for their Always On VPN deployments.

Note: The AD CS remote server administration tools (RSAT) must be installed to access all of the PSPKI module’s functionality.

Installation

Run the following PowerShell command to install the PSPKI PowerShell module.

Install-Module -Name PSPKI

Always On VPN and PSPKI

Always On VPN Administrators will immediately find a few PSPKI functions helpful when implementing and supporting Always On VPN.

Test-WebServerSSL – This function will connect to a remote web server and display details about the TLS certificate included in the response. This can be especially helpful when troubleshooting SSTP VPN connections.

Convert-PfxToPem – This is a handy utility for converting a PFX file to the PEM format. This is commonly required when importing CA certificates on non-Microsoft platforms, security devices, and load balancers.

Convert-PemToPfx – Occasionally, administrators must convert a certificate and private key in PEM format to PFX to install on a Windows server. This tool allows administrators to perform this task easily.

Get-CertificationAuthority – This function quickly enumerates all enterprise CA servers and displays information about their hostname, accessibility, service status, and type.

Ping-ICertInterface – This function helps troubleshoot CA connectivity issues. Administrators can quickly determine if a CA is reachable and capable of issuing a certificate using this command.

Get-CaTemplate – This command displays a list of certificate templates published on the specified target CA server. The certificate template’s display name and the minimum support CA version are provided. In addition, the output indicates if certificate autoenrollment is enabled on the template.

Much More

The PSPKI PowerShell module for AD CS has many tools for configuring and managing AD CS. PSPKI recently received a major update to version 4.0. Download and install PSPKI today. It will make your life easier, I can assure you!

Additional Information

PSPKI PowerShell Module – PowerShell Gallery

PSPKI PowerShell Module – GitHub

AOVPNTools PowerShell Module – PowerShell Gallery

AOVPNTools PowerShell Module – GitHub

InboxAccountingDatabaseManagement PowerShell Module

InboxAccontingDatabaseManagement – PowerShell Gallery

InboxAccountingDatabaseManagement – GitHub

Intune Certificate Connector Configuration Failed

Troubleshooting Always On VPN Error 691 and 812 – Part 2

The Microsoft Intune Certificate Connector must be deployed on-premises to provision and manage enterprise PKI certificates using Intune. The Intune Certificate Connector supports the deployment of SCEP, PKCS, PKCS imported certificates, or any combination of these. The connector can be configured to run under the SYSTEM account or optionally (and recommended) a domain service account. When using a service account, the service account must have permission to log on as a service on the server where the Intune Certificate Connector server.

Access is Denied

Even when all prerequisites are met, administrators may still find the installation of the Intune Certificate Connector fails with the following error message.

“Configuring Microsoft Intune Certificate Connector failed. No changes were made to Feature or Proxy settings. Please try again.”

“Unexpected Failure. Error: System.lnvalidOperationException: Cannot open PFXCertificateConnectorSvc service on computer ‘.’ System.ComponentModel.Win32Exception: Access is denied”

Workaround

After the connector installation fails, open the file explore and navigate to C:\Program Files\Microsoft Intune\PFXCertificateConnector\ConnectorUI. Right-click PFXCertificateConnectorUI.exe and choose ‘Run as administrator’.

Run through the connector installation wizard again, and it should install without issue.

To avoid this problem for future Intune Certificate Connector deployments, administrators can right-click the Intune Certificate Connector installer (IntuneCertificateConnector.exe) and choose ‘Run as administrator’.

Additional Information

Microsoft Intune Certificate Connector Configuration Failure (Part 1)

Microsoft Intune Certificate Connector Service Account and PKCS

Microsoft Intune Learning Resources for Always On VPN Admins

Microsoft Intune Certificate Connector Overview

Always On VPN RRAS and Stale Connections

Always On VPN Updates for RRAS and IKEv2

Always On VPN administrators may be familiar with an issue that affects Windows Server Routing and Remote Access Service (RRAS) servers, where many stale VPN connections appear in the list of active connections. The issue is most prevalent when using IKEv2, either for the Always On VPN device tunnel or the user tunnel. Typically, this does not cause problems, but some administrators have reported issues related to port exhaustion or failed IKEv2 connections when many stale connections are present. Stale connections happen so frequently that I created a PowerShell script to clean them up on the RRAS server. Restarting the RemoteAccess service or rebooting the server also clears stale connections.

Microsoft Fix

Thankfully, Microsoft has addressed these issues in Windows Server 2019 and Windows Server 2022 this month. An update is now available in the March 2023 security update that resolves this problem.

You can find more information about the updates here.

The update was not made available for Windows Server 2016, however. Organizations are encouraged to upgrade to Windows Server 2019 or later to address this problem.

Additional Information

Always On VPN Updates for RRAS and IKEv2

Always On VPN IKEv2 Load Balancing and NAT

Always On VPN and IKEv2 Fragmentation