Security

Create a Self-Signed Certificate Using PowerShell

security-red-hero-img

In today’s Ask the Admin, I’ll show you how to quickly create a self-signed certificate.

Self-signed certificates are not recommended for use in production environments, but come in handy for test scenarios where a certificate is a requirement but you don’t have the time or resources to either buy a certificate or deploy your own Public Key Infrastructure (PKI).

Create a self-signed certificate using PowerShell (Image Credit: Russell Smith)
Create a self-signed certificate using PowerShell (Image Credit: Russell Smith)

But generating self-signed certificates in Windows has traditionally been a bit of a pain, at least if you didn’t have Visual Studio or IIS on hand, as both these products include the ability to generate self-signed certificates. The makecert command line tool was otherwise the “go to” tool, but was only available as part of the Windows SDK, which is a hefty product to download and install just for the sake of using makecert.

Sponsored Content

Read the Best Personal and Business Tech without Ads

Staying updated on what is happening in the technology sector is important to your career and your personal life but ads can make reading news, distracting. With Thurrott Premium, you can enjoy the best coverage in tech without the annoying ads.

Starting in PowerShell version 4.0, Microsoft introduced the New-SelfSignedCertificate cmdlet, making it much easier to create self-signed certificates. To get started, you’ll need a Windows device running PowerShell 4.0 or higher.

  • Open a PowerShell prompt. In Windows 10, type powershell in the search dialog on the taskbar, right-click Windows PowerShell in the list of app results, select Run as administrator from the menu and then enter an administrator username and password. The New-SelfSignedCertificate can only install certificates to the My certificate store, and that requires local administrator rights on the device.
  • If you’re running a different version of Windows, check the PowerShell version by running the code shown below.

$PSVersionTable.PSVersion

If you need to update PowerShell to version 5, you can download the Windows Management Framework for Windows 7 and Windows 8.1 here.

  • Now run the New-SelfSignedCertificate cmdlet as shown below to add a certificate to the local store on your PC, replacing testcert.petri.com with the fully qualified domain name (FQDN) that you’d like to use.

$cert = New-SelfSignedCertificate -certstorelocation cert:\localmachine\my -dnsname testcert.petri.com

The next step is to export a self-signed certificate. But first we’ll need to create a password as shown below:
$pwd = ConvertTo-SecureString -String ‘passw0rd!’ -Force -AsPlainText

Now we can export a self-signed certificate using the Export-PfxCertificate cmdlet. We’ll use the password ($pwd) created above, and create an additional string ($path), which specifies the path to the certificate created with New-SelfSignedCertificate cmdlet.
$path = 'cert:\localMachine\my\' + $cert.thumbprint Export-PfxCertificate -cert $path -FilePath c:\temp\cert.pfx -Password $pwd

Note that the c:\temp directory, or whatever directory you specify in the -FilePath parameter, must already exist. You can now import the cert.pfx file to install the certificate.

Related Topics:

BECOME A PETRI MEMBER:

Don't have a login but want to join the conversation? Sign up for a Petri Account

Register
Comments (0)

Leave a Reply

IT consultant, Contributing Editor @PetriFeed, and trainer @Pluralsight. All about Microsoft, Office 365, Azure, and Windows Server.

Download this eBook!

External Sharing and Guest User Access in Microsoft 365 and Teams

his eBook will dive into policy considerations you need to make when creating and managing guest user access to your Teams network, as well as the different layers of guest access and the common challenges that accompany a more complicated Microsoft 365 infrastructure. The eBook will also outline some of the major decision points across four general-purpose guest access policy scenarios for how an organization can set this up with standard licensing.

Download Now

Sponsored By