All posts tagged CertKit

CertKit Agent Support for Always On VPN SSTP and DirectAccess IP-HTTPS TLS Certificates

With public TLS certificate lifetimes set to drop to 200 days soon (next week!), Always On VPN and DirectAccess administrators face an increased risk of service disruption if certificates aren’t renewed on time. These shorter certificate lifetimes require more frequent renewals, substantially increasing management overhead. Although 200 days equate to roughly a twice-a-year renewal, lifetimes will decrease further to 100 days next year and eventually to just 47 days in 2029. SSTP and IP-HTTPS are TLS-based tunneling protocols used by Always On VPN and DirectAccess, respectively, tying their certificate health directly to remote access availability. Now is the time to automate the enrollment and renewal of Always On VPN SSTP and DirectAccess IP-HTTPS/TLS certificates to ensure reliable operation in the future.

Always On VPN

Previously, I wrote about using CertKit.io to automate the enrollment and renewal of public TLS certificates for Always On VPN. CertKit is an online service that administrators can use to delegate the task of enrolling for short-lived certificates from Let’s Encrypt. In that post, I shared some sample code to retrieve the certificate from CertKit and assign it to the SSTP listener for the Routing and Remote Access Service (RRAS). However, CertKit added new features to its solution, eliminating the need for additional code.

CertKit Agents

Recently, CertKit introduced CertKit Agents. These lightweight software agents are installed on Windows Servers (other operating systems are supported as well) to automate the process of downloading CertKit certificates and installing them in the local computer certificate store. Importantly, they now specifically support both the Always On VPN (SSTP) and DirectAccess (IP-HTTPS) workloads natively.

Always On VPN

The CertKit agent automatically detects the Routing and Remote Access (RRAS) workload and updates the certificate binding for the SSTP listener accordingly. Since this process requires a service restart, which terminates all current VPN connections, CertKit allows you to select an outage window for certificate updates.

Here, administrators can define the day(s) and time window during which the agent is authorized to restart the RemoteAccess service when updating the TLS certificate for SSTP. The day and time are based on the server’s configured time zone settings.

DirectAccess

Beginning with CertKit agent v1.6.2, the agent automatically detects whether DirectAccess is configured, enabling IP-HTTPS TLS certificates to be automatically enrolled and renewed. However, additional configuration is required. The following changes must be made to support CertKit for DirectAccess.

Service Account – Administrators must configure a service account in Active Directory for the CertKit agent. A Group Managed Service Account (gMSA) is preferred, but a standard domain service account is also supported.
GPO Delegation – CertKit service account must be delegated the ‘Edit settings, delete, and modify security’ permission on the DirectAccess server and client settings GPOs.
Log On as a Service – When using a domain service account, administrators must grant the CertKit service the ‘Log on as a service’ right on the DirectAccess server. However, when using gMSA, the ‘Log on as a service’ right is not required.
Local Administrator – Administrators must also add the CertKit agent service account to the Local Administrators group on the server.

Configuration Script

I have published a PowerShell script to simplify configuring the CertKit agent on DirectAccess servers. The script automatically performs all required tasks for the CertKit agent to work with DirectAccess. You will find the Enable-DACertKit.ps1 PowerShell script on GitHub. Alternatively, you can install the script directly from the PowerShell Gallery.

Install-Script -Name Enable-DACertKit -Scope CurrentUser

After installing the CertKit agent, run the PowerShell script to complete the configuration. Next, authorize the agent in the CertKit management portal and assign a certificate. Once complete, CertKit can fully manage the IP-HTTPS TLS certificate for DirectAccess.

Note: Like Always On VPN, changes to the DirectAccess IP-HTTPS certificate require a service restart, which is disruptive. Be sure to define a maintenance window (as shown previously) to ensure the change is made during non-peak times.

Summary

As TLS certificate lifecycles continue to shrink, automating certificate enrollment and renewal has become essential for both Always On VPN and DirectAccess environments. CertKit agents streamline this process by automatically retrieving, installing, and binding certificates for SSTP and IP-HTTPS, all while supporting scheduled outage windows to minimize disruption. With these new capabilities, administrators can significantly reduce operational overhead and ensure consistent, reliable remote access services without manual intervention. Visit CertKit.io to get started today.

More Information

If you would like to learn more about CertKit or see a demonstration with Always On VPN or DirectAccess, fill out the form below, and I’ll provide you with more details.

Additional Information

Always On VPN SSTP Certificate Automation with CertKit

CertKit Agents

Enable-DACertKit.ps1 on GitHub

Enable Group Managed Service Accounts

Always On VPN SSTP Certificate Automation with CertKit

With public TLS certificates moving to significantly shorter certificate lifetimes, eventually just 47 days, Always On VPN administrators supporting Secure Socket Tunneling Protocol (SSTP) connections must prepare to address this eventuality. The first milestone for shortened public TLS certificate lifetimes is a few months, on March 15, 2026, when public TLS certificate lifetimes will be reduced from a maximum of 398 days to 200 days. One year later, on March 15, 2027, they will be reduced to just 100 days. Now is the time to begin planning an automated certificate enrollment solution to reduce administrative overhead and ensure uninterrupted connectivity for remote users.

Previous Approaches: PowerShell and Posh-ACME

In the past, I’ve written about using Let’s Encrypt Certificates for Always On VPN using the Po s h-ACME PowerShell module. I’ve also posted some sample code to demonstrate how to integrate with a DNS provider to automate publishing the ACME challenge to public DNS for certificate enrollment verification. However, this assumes your DNS provider supports this option. Some do not. In addition, granting write permissions to public DNS via an API key introduces significant security risks. So, if direct ACME DNS automation isn’t viable in your environment, CertKit is an excellent alternative.

CertKit: Automated Certificate Issuance, Monitoring, and Alerting

To address these limitations, administrators can use the CertKit service. With CertKit, you delegate the Let’s Encrypt certificate enrollment process to them by simply creating a CNAME record in your public DNS. Once complete, CertKit handles the entire process transparently.

Issuance

Today, CertKit supports issuing certificates using Let’s Encrypt. In the future, support for additional certificate providers such as Google Trust and ZeroSSL will be added. CertKit supports Let’s Encrypt certificates using RSA (2048-bit) and Elliptic Curve (recommended). Certificates can be issued for an individual resource, a group of resources (multi-SAN), and a domain wildcard (e.g., *.example.net).

Monitoring

In addition to certificate issuance and management, CertKit offers domain TLS certificate monitoring to track your public assets. You can monitor your CertKit-managed certificates easily, but you can also add other services using TLS and track them on the same console. In this example, I’m using CertKit to manage certificates for two VPN servers (indicated by solid green dots) and to monitor my public websites, for which certificate management is handled by their respective hosting providers.

Alerts and Notifications

CertKit will automatically send emails to let you know when a certificate is expiring and if a CertKit-managed certificate has been renewed.

Pending certificate expiration.

Successful certificate renewal.

Certificate Retrieval

Once CertKit completes the enrollment process on your behalf, it stores all certificate files (.PFX, .PEM, and .KEY) in a secure S3-compatible storage bucket. While an administrator could easily retrieve and install them manually, automation will help reduce administrative overhead, especially as public TLS certificate lifetimes are further reduced. You can download certificate files programmatically in several ways.

PowerShell

The first way to download the certificate files from CertKit is to use the AWSPowerShell module. However, the AWSPowerShell is relatively heavy and is overkill for this specific use case. A better alternative is to use the MinIO client.

MinIO

The MinIO client (mc.exe) is an open-source command-line tool developed by MinIO. It provides access to any S3-compatible storage, which CertKit uses in its environment. MinIO is a single, portable executable installer that’s easy to use and well-documented.

Sample Code

I’ve published some sample code to demonstrate how to use the MinIO client to retrieve certificates from CertKit and install them on a Windows Server Routing and Remote Access (RRAS) server. You can find the sample code on GitHub here.

https://github.com/richardhicks/aovpn/blob/master/Install-SstpLetsEncryptCertificate-Certkit.ps1

Note: This sample code demonstrates how to download a .PFX file from CertKit and install it on the RRAS server. It is designed to run as a scheduled task in Windows during non-peak times. The code includes robust checks for service viability and will reboot the server if they fail. As such, this sample code could cause service disruptions, so use it with caution.

Cost

Today, CertKit is in beta and is free for everyone to use. In the future, there will be both free and paid tiers. You can learn more about their pricing models and sign up for the service at CertKit.io.

Learn More

If you’d like to learn more about CertKit and how you can leverage it for Always On VPN and other workloads in your environment, or you’d like to see a demonstration of CertKit, fill out the form below, and I’ll provide you with more information.

Additional Information

CertKit

Install-SstpLetsEncryptCertificate-Certkit.ps1 on GitHub

Always On VPN SSTP and 47-Day TLS Certificates

Always On VPN SSTP with Let’s Encrypt Certificates

Richard M. Hicks Consulting, Inc.

Microsoft MVP

Consulting

Pluralsight

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All posts tagged CertKit

CertKit Agent Support for Always On VPN SSTP and DirectAccess IP-HTTPS TLS Certificates

Always On VPN

CertKit Agents

Always On VPN